ประกวดราคาจ้างซ่อมหม้อแปลงไฟฟ้า 50 MVA สถานีไฟฟ้าตะพานหิน (ชั่วคราว) จ.พิจิตร

• ซ่อมหม้อแปลงไฟฟ้ากำลัง สถานีไฟฟ้าตะพานหิน (ชั่วคราว) ให้กลับมาใช้งานได้ตามปกติ
• จัดหาและติดตั้งอุปกรณ์ใหม่ทดแทนอุปกรณ์เดิมที่ชำรุด
• คืนสภาพหม้อแปลงให้พร้อมใช้งาน และทำการทดสอบตามมาตรฐาน

• จัดหาอุปกรณ์ใหม่ตามรายการที่กำหนดใน TOR
  • ตู Remote control cabinet (RCC)
  • ตู Local control cabinet (LCC)
  • Winding temperature indicator
  • Oil temperature indicator
  • Pressure relief device สำหรับ Main tank
  • Pressure relief device สำหรับ OLTC
  • Buchholz relay สำหรับ Main tank
  • Protective relay สำหรับ OLTC
  • Valve ทุกจุดของหม้อแปลงฯ
  • Oil Conservator tank พร้อม Rubber bag สำหรับ Main tank
  • Dehydrating Breather
  • Control cable สำหรับเปลี่ยนทดแทนของเดิม จากอุปกรณ์ประกอบทุกตัว มายังตู้ LCC
  • Control cable สำหรับเปลี่ยนทดแทนของเดิม จากตู้ LCC มายังตู้ RCC
• เปลี่ยนอุปกรณ์ที่จัดหามาทดแทนของเดิม และจัดเก็บอุปกรณ์เดิมอย่างมิดชิด
• คืนสภาพหม้อแปลงไฟฟ้ากำลังให้พร้อมใช้งาน
  • เติมน้ำมันกลับคืน พร้อมกรองน้ำมัน
  • ทดสอบ Field test
  • ทดสอบ Commissioning test ร่วมกับ กฟภ.
• ออกแบบ Wiring ของอุปกรณ์ทั้งหมด และส่งแบบให้ กฟภ. อนุมัติก่อนดำเนินการ
• จัดหาทรัพยากร ได้แก่ แรงงาน พาหนะ เครื่องมือ เครื่องใช้ และอุปกรณ์ที่จำเป็นในการดำเนินงาน
• ปฏิบัติตามพระราชบัญญัติความปลอดภัย อาชีวอนามัย และสภาพแวดล้อมในการทำงาน พ.ศ. 2554 และกฎหมายอื่นๆ ที่เกี่ยวข้อง
• จัดทำแผนการทำงานในทุกกระบวนการตั้งแต่เริ่มต้นจนแล้วเสร็จ แจ้งให้กับ กฟภ. ทราบ ก่อนเริ่มดำเนินการ

• อุปกรณ์ใหม่ตามรายการที่กำหนด
• หม้อแปลงไฟฟ้ากำลังที่ได้รับการซ่อมแซมและคืนสภาพพร้อมใช้งาน
• แบบ Wiring ของอุปกรณ์ทั้งหมดที่ได้รับการอนุมัติจาก กฟภ.
• รายงานผลการทดสอบ Field test และ Commissioning test
• แผนการทำงาน

ภายใน 240 วัน นับถัดจากวันลงนามในสัญญา

• Standards Compliance: อ้างอิงมาตรฐาน IEC 60214-1 หรือเทียบเท่า สำหรับ OLTC

รายละเอียดตามเอกสาร TOR

• อ้างอิงตามเอกสารแนบ Specification No. RTRN-014/2559
• Vector group: Dyn1 หรือ YNyn0(d1)
• Short circuit impedance: 7.5% ที่ self-cooled rating
• Limits of temperature rise: ตามที่กำหนดใน TOR
• Core: ทำจาก high quality non-aging, high permeability silicon steel
• Tank: สามารถทนต่อแรงดันภายในและสูญญากาศได้
• Insulating oil: เป็นไปตามมาตรฐาน IEC 60296 หรือเทียบเท่า
• Oil preservation system: Conservator system แบบ air-bag type
• Bushings: เป็นไปตามมาตรฐาน IEC 60137 สำหรับ HV และ IEC หรือ DIN สำหรับ MV
• On-Load Tap-Changer (OLTC): เป็นไปตามมาตรฐาน IEC 60214-1 หรือเทียบเท่า

• การเบิกจ่ายเงิน: เบิกจ่ายเงินเป็น 1 งวด เมื่อผู้รับจ้างดำเนินการตามขอบเขตงานฯ แล้วเสร็จ ถูกต้องครบถ้วน และผ่านการตรวจรับจากคณะกรรมการตรวจรับพัสดุของ กฟภ. แล้ว
• ค่าปรับ: กรณีส่งมอบงานล่าช้าเกินกำหนด (240 วันนับถัดจากวันลงนามในสัญญา) กฟภ. จะคิดค่าปรับในอัตราร้อยละ 0.2 ต่อวัน ของราคางานจ้างทั้งหมด

• คำถาม: จะต้องจัดเก็บอุปกรณ์เดิมที่ถอดออกมาอย่างไร?
  คำตอบ: ผู้รับจ้างจะต้องจัดหาลังไม้สำหรับจัดเก็บอุปกรณ์ที่ถอดออกมาให้มิดชิด

  • คำถาม: การคืนสภาพหม้อแปลงให้พร้อมใช้งาน รวมถึงขั้นตอนอะไรบ้าง?
    คำตอบ: รวมถึงการเติมน้ำมันกลับคืน พร้อมกรองน้ำมัน จากนั้นจึงทำการทดสอบ Field test และร่วมทดสอบ Commissioning test กับ กฟภ.

  • คำถาม: ผู้รับจ้างต้องรับผิดชอบอย่างไรหากอุปกรณ์ของ กฟภ. เสียหาย?
    คำตอบ: ผู้รับจ้างจะต้องรับผิดชอบกรณีเกิดความเสียหายกับอุปกรณ์ต่างๆ ที่เป็นทรัพย์สินของ กฟภ. หรืออุปกรณ์ต่างๆ ที่อยู่ระหว่างการส่งมอบงานจ้าง อันเกิดจากการกระทำของผู้รับจ้าง ที่ส่งผลทำให้อุปกรณ์ดังกล่าวชำรุดในระหว่างขั้นตอนการดำเนินการ

  • คำถาม: ต้องส่งเอกสารอะไรให้ กฟภ. ก่อนเริ่มดำเนินการ?
    คำตอบ: ผู้รับจ้างจะต้องทำแผนการทำงานในทุกกระบวนการตั้งแต่เริ่มต้นจนแล้วเสร็จ ตามระยะเวลาที่กำหนดในสัญญา แจ้งให้กับ กฟภ. ทราบ ก่อนเริ่มดำเนินการ

  • คำถาม: หาก กฟภ. พบว่าการทำงานของผู้รับจ้างไม่เหมาะสม จะดำเนินการอย่างไร?
    คำตอบ: คณะกรรมการตรวจรับหรือตัวแทนของ กฟภ. สามารถเข้าตรวจสอบทุกขั้นตอนในการดำเนินการ หากพบว่าการทำงานของผู้รับจ้างไม่เหมาะสม กฟภ. มีสิทธิ์สั่งระงับการปฏิบัติงาน

  • คำถาม: ค่าใช้จ่ายในการดำเนินการจะต้องแจกแจงรายละเอียดอย่างไรในการเสนอราคา?
    คำตอบ: ในการเสนอราคา ผู้รับจ้างจะต้องเสนอราคาโดยแจกแจงราคาตามรายละเอียดดังนี้ ค่าอุปกรณ์ตามรายการในข้อ 1 (ราคาต่อหน่วยแยกตามรายการ) พร้อมทั้งระบุผลิตภัณฑ์ รุ่น และประเทศผู้ผลิตอุปกรณ์, ค่าแรง

  • คำถาม: คุณสมบัติของ Insulating oil ที่ใช้ในหม้อแปลงไฟฟ้าต้องเป็นอย่างไร
    คำตอบ: คุณภาพของ Insulating oil ต้องเป็นไปตามมาตรฐาน IEC 60296 หรือเทียบเท่า โดยต้องจัดเป็น Uninhibited insulating oil class 1

  • คำถาม: ระบบ Oil preservation ของหม้อแปลงไฟฟ้าต้องเป็นแบบใด
    คำตอบ: ต้องเป็นระบบ Conservator system แบบ Air-bag type พร้อม Buchholz relay ที่จุดสูงสุด

  • คำถาม: ระบุยี่ห้อของ Pressure relief device ได้หรือไม่
    คำตอบ: สำหรับ Main tank (Messko รุ่น MPrec), สำหรับ OLTC (Messko รุ่น MPrec)

  • คำถาม: ผู้ผลิต Buchholz relay ต้องเป็นผลิตภัณฑ์จากที่ไหน
    คำตอบ: ผลิตภัณฑ์ EMB

งานจ างซ อมหม อแปลงไฟฟ ากำลัง สถานีไฟฟ าตะพานหิน (ชั่วคราว) เลขที่ N2.EB(กสฟ.) - 003/2567
รายละเอียดดังนี้
รายการ
จำนวน (แผ น)
เลขหน า
ร างขอบเขตงานงานจ างซ อมหม อแปลงไฟฟ ากำลัง สถานีไฟฟ าตะพานหิน (ชั่วคราว)
3
1-3
รายการที่ 1, 2, 10 : ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION (RTRN-014/2559)
84
4-87
รายการที่ 3, 4 : TEMPERATURE MEASUREMENT (RTRN-032/2549)
5
88 - 92
รายการที่ 5, 6 : PRESSURE RELIEF DEVICE
1
93
รายการที่ 11 : DEHYDRATING BREATHER
2
94 - 95
รายการที่ 12, 13 : CONTORL CABLE (RCBL-303/2551)
12
96 - 107
เอกสารด านความปลอดภัย
15
108 - 122
รวม
122

1
ร างขอบเขตของงาน
งานจางซ อมหมอแปลงไฟฟ ากำลัง สถานีไฟฟ าตะพานหิน (ชั่วคราว)

1. การจัดหาอุปกรณ+
   ผู รับจ าง จะต องจัดหาอุปกรณ)ซึ่งเป,นของใหม และไม เคยใช งานมาก อน ตามรายละเอียดในตารางต อไปนี้
   ที่
   รายการ
   จำนวน
   หน วย
   1
   ตู Remote control cabinet (RCC) พร อมอุปกรณ)ประกอบภายใน ให เป,นไปตามฟAงก)ชั่น เดิมของหม อแปลงฯ และมีรูปแบบตามที่กำหนดใน Specification No. RTRN-014/2559
   1
   set
   2
   ตู Local control cabinet (LCC) พร อมอุปกรณ)ประกอบภายใน ให เป,นไปตามฟAงก)ชั่นเดิม ของหม อแปลงฯ และมีรูปแบบตามที่กำหนดใน Specification No. RTRN-014/2559
   1
   set
   3
   Winding temperature indicator (ตามที่กำหนดใน Specification No. RTRN-032/2549 PEA Material No. 05100112)
   3
   set
   4
   Oil temperature indicator (ตามที่กำหนดใน Specification No. RTRN-032/2549 PEA Material No. 05100111)
   1
   set
   5
   Pressure relief device สำหรับใช งานกับ Main tank (Messko รุ น MPrec)
   1
   set
   6
   Pressure relief device สำหรับใช งานกับ OLTC (Messko รุ น MPrec)
   1
   set
   7
   Buchholz relay สำหรับใช งานกับ Main tank (2 ลูกลอย พร อม Contact) (ผลิตภัณฑ) EMB)
   1
   set
   8
   Protective relay สำหรับใช งานกับ OLTC (ผลิตภัณฑ) MR รุ น RS2001)
   1
   set
   9
   Valve ทุกจุดของหม อแปลงฯ
   1
   lots
   10
   Oil Conservator tank พร อม Rubber bag สำห รับ Main tank (ต ามที ่กำหนดใน Specification No. RTRN-014/2559)
   1
   set
   11
   Dehydrating Breather
   2
   set
   12
   Control cable สำหรับเปลี่ยนทดแทนของเดิม จากอุปกรณ)ประกอบทุกตัว มายังตู LCC
   1
   lots
   13
   Control cable สำหรับเปลี่ยนทดแทนของเดิม จากตู LCC มายังตู RCC
   1
   lots

2. รายละเอียดการดำเนินการ
   2.1 ผู รับจ างจะต องทำการเปลี่ยนอุปกรณ)ที่จัดหาตามข อ 1. ทดแทนของเดิม โดยที่อุปกรณ)ที่ถอดออกมา ผู รับจ างจะต องจัดหาลังไม สำหรับจัดเก็บให มิดชิด ทั้งนี้ การเปลี่ยนอุปกรณ)รวมถึงการออกแบบดัดแปลงตาม ความจำเป,น เพื่อให อุปกรณ)ใหม ที่จัดหามา สามารถติดตั้งใช งานทดแทนของเดิมได อย างมีประสิทธิภาพโดย ไม เกิดปAญหา
   2.2 ผู รับจ างจะต องทำการคืนสภาพหม อแปลงไฟฟ ากำลังให พร อมใช งาน ได แก การเติมน้ำมันกลับคืน พร อมกรองน้ำมัน จากนั้น จึงทำการทดสอบ Field test และร วมทดสอบ Commissioning test กับ กฟภ. โดยทุกกระบวนการ ให เป,นไปตามมาตรฐานที่ กฟภ. ยอมรับ
   2.3 ผู รับจ างจะต องทำการออกแบบ Wiring ของอุปกรณ)ทั้งหมด และทำการส งแบบเหล านั้นมาให กฟภ. เพื่อทำการอนุมัติก อนดำเนินการ
   งานจ างซ อมหม อแปลงไฟฟ ากำลัง สถานีไฟฟ าตะพานหิน (ชั่วคราว)
   2
   2.4 ผู้รับจ้างจะต้องจัดหาทรัพยากร ได้แก่ แรงงาน พาหนะ เครื่องมือ เครื่องใช้ และอุปกรณ์ที่จำเป็นใน การดำเนินงานทั้งหมด

3. ขอกําหนดดานความปลอดภัย
   3.1 ผู้รับจ้างต้องปฏิบัติตามพระราชบัญญัติความปลอดภัย อาชีวอนามัย และสภาพแวดล้อมในการทำงาน พ.ศ. 2554 และกฎกระทรวงกําหนดมาตรฐานในการบริหาร จัดการ และดําเนินการด้านความปลอดภัย อาชีวอนามัย และสภาพแวดล้อมในการทํางานเกี่ยวกับไฟฟ้า พ.ศ.2558 รวมทั้งกฎกระทรวงและกฎหมายอื่นๆ ที่เกี่ยวข้องกับลักษณะงานตามขอบเขตงาน
   3.2 ผู้รับจ้างต้องจัดเจ้าหน้าที่ความปลอดภัยในการทำงานระดับหัวหน้างาน (จป.หัวหน้างาน) ตามที่ กฎหมายกำหนด และปฏิบัติตามกฎกระทรวงกำหนดมาตรฐานในการบริหารและการจัดการด้านความ ปลอดภัย อาชีวอนามัย และสภาพแวดล้อมในการทำงาน พ.ศ. 2549 โดย จป.หัวหน้างานดังกล่าวต้อง ประสานงานกับตัวแทนของผู้ว่าจ้าง ในการปฏิบัติงานที่เกี่ยวข้องด้านความปลอดภัยในการทำงาน พร้อมทั้ง จัดส่งหลักฐานการประสานงานกันเป็นลายลักษณ์อักษรให้ผู้ว่าจ้างรับทราบด้วย
   3.3 ผู้รับจ้างจะต้องจัดหาอุปกรณ์ป้องกันภัยส่วนบุคคล (PPE) ให้แก่ผู้ปฏิบัติงานของผู้รับจ้างอย่าง ครบถ้วนและเพียงพอสำหรับทุกคน
   3.4 ผู้รับจ้างจะต้องจัดส่งเอกสารขออนุญาตทำงาน กฟภ. (PEA Work Permit) สำหรับการลงนามขอเข้า ปฏิบัติงานภายในสถานีไฟฟ้าของการไฟฟ้าส่วนภูมิภาค ตามแบบฟอร์มที่ กฟภ. กำหนด
   3.5 ผู้รับจ้างจะต้องจัดทำเอกสารการประชุมด้านความปลอดภัยในการทำงานก่อนเริ่มปฏิบัติงาน (Safety Talk) รวมทั้งการประชุมเรื่องการหยั่งรู้อันตราย (KYT) ในการปฏิบัติงาน แยกเป็นรายวันและต้องดำเนินการ ทุกวันที่เข้าปฏิบัติงานในสถานีไฟฟ้า ทั้งนี้ผู้รับจ้างจะต้องควบคุมให้ผู้ปฏิบัติงานเข้าร่วมประชุมและให้ลงนามไว้ เป็นหลักฐานทุกคน
   หมายเหตุ หากผู้รับจ้างไม่ปฏิบัติตามข้อตกลงด้านความปลอดภัยในการทำงานข้อ 3.1 – 3.5 ให้ครบถ้วนแล้ว กฟภ. มีสิทธิ์สั่งระงับการปฏิบัติงาน และผู้รับจ้างไม่สามารถนำเหตุดังกล่าวมาขอสงวนสิทธิ์ในการงดเว้นค่าปรับ กรณีส่งมอบงานล่าช้าได้

4. ขอกําหนดอื่นๆ
   4.1 ผู้รับจ้างจะต้องทำแผนการทำงานในทุกกระบวนการตั้งแต่เริ่มต้นจนแล้วเสร็จ ตามระยะเวลาที่ กำหนดในสัญญา แจ้งให้กับ กฟภ. ทราบ ก่อนเริ่มดำเนินการ
   4.2 คณะกรรมการตรวจรับหรือตัวแทนของ กฟภ. สามารถเข้าตรวจสอบทุกขั้นตอนในการดำเนินการ หากพบว่าการทำงานของผู้รับจ้างไม่เหมาะสม กฟภ. มีสิทธิ์สั่งระงับการปฏิบัติงาน และผู้รับจ้างไม่สามารถนำ เหตุดังกล่าวมาขอสงวนสิทธิ์ในการงดเว้นค่าปรับกรณีส่งมอบงานล่าช้าได้
   4.3 ผู้รับจ้างจะต้องรับผิดชอบกรณีเกิดความเสียหายกับอุปกรณ์ต่างๆ ที่เป็นทรัพย์สินของ กฟภ. หรือ อุปกรณ์ต่างๆ ที่อยู่ระหว่างการส่งมอบงานจ้าง อันเกิดจากการกระทำของผู้รับจ้าง ที่ส่งผลทำให้อุปกรณ์ ดังกล่าวชำรุดในระหว่างขั้นตอนการดำเนินการ
   งานจ้างซ่อมหม้อแปลงไฟฟ้ากำลัง สถานีไฟฟ้าตะพานหิน (ชั่วคราว)
   3
   4.4 ในการขอเข้าพื้นที่เพื่อปฏิบัติงาน ผู้รับจ้างจะต้องปฏิบัติตามข้อกำหนด หรือประกาศของหน่วยงานที่ เกี่ยวข้องตามแต่ละพื้นที่

5. การเสนอราคา
   ในการเสนอราคา ผู้รับจ้างจะต้องเสนอราคาโดยแจกแจงราคาตามรายละเอียดดังนี้
   5.1 ค่าอุปกรณ์ตามรายการในข้อ 1 (ราคาต่อหน่วยแยกตามรายการ) พร้อมทั้งระบุผลิตภัณฑ์ รุ่น และ ประเทศผู้ผลิตอุปกรณ์
   5.2 ค่าแรง

6. กําหนดส งมอบงาน
   ภายใน 240 วัน นับถัดจากวันลงนามในสัญญา

7. การเบิกจ ายเงิน
   เบิกจ่ายเงินเป็น 1 งวด เมื่อผู้รับจ้างดำเนินการตามขอบเขตงานฯ แล้วเสร็จ ถูกต้องครบถ้วน และผ่านการ ตรวจรับจากคณะกรรมการตรวจรับพัสดุของ กฟภ. แล้ว

8. ค าปรับ
   กรณีส่งมอบงานล่าช้าเกินกำหนด (240 วันนับถัดจากวันลงนามในสัญญา) กฟภ. จะคิดค่าปรับในอัตราร้อยละ 0.2 ต่อวัน ของราคางานจ้างทั้งหมด
   งานจ้างซ่อมหม้อแปลงไฟฟ้ากำลัง สถานีไฟฟ้าตะพานหิน (ชั่วคราว)
   4
   ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
   Contents
   C1 General material and packing instructions
   1a Scope…………………………………………………………………………………………………………………..1 1b Standards……………………………………………………………………………………………………………1 1c Principal requirements……………………………………………………………………………………….2 1c.1 General………………………………………………………………………………………………………………..2 1c.2 Design requirements…………………………………………………………………………………………..2 1c.3 Site and service conditions…………………………………………………………………………………….3 1c.4 Equipments characteristics…………………………………………………………………………………….3 1c.4.1 Transformers………………………………………………………………………………………………………..3 1c.4.1.1 Requirements……………………………………………………………………………………………………….3 1c.4.1.2 Ratings………………………………………………………………………………………………………………..7 1c.4.2 On-Load Tap-Changer (OLTC) …………………………………………………………………………..8 1c.4.2.1 Requirements……………………………………………………………………………………………………….8 1c.4.2.2 OLTC compartment …………………………………………………………………………………………….8 1c.4.2.3 Operation……………………………………………………………………………………………………………..9 1c.4.2.4 Driving mechanism………………………………………………………………………………………………9 1c.4.3 Cooling equipment……………………………………………………………………………………………….10 1c.4.3.1 Requirements……………………………………………………………………………………………………….10 1c.4.3.2 Cooling local control…………………………………………………………………………………………….11
   1c.4.3.3 Cooling remote control…………………………………………………………………………………………11 1c.4.4 Control cabinet……………………………………………………………………………………………………..11 1c.4.4.1 Local control cabinet…………………………………………………………………………………………….11 1c.4.4.2 Remote control cabinet…………………………………………………………………………………………12 1c.4.4.3 Remote controlled functions………………………………………………………………………………….13 1c.4.4.4 Annunciator panel………………………………………………………………………………………………..13 1c.4.5 Safety factor…………………………………………………………………………………………………………14 1c.4.6 Instrument transformers………………………………………………………………………………………..15 1c.4.6.1 Current transformer………………………………………………………………………………………………15 1c.4.6.2 Voltage transformer………………………………………………………………………………………………16 1c.4.7 Earthing……………………………………………………………………………………………………………….17 1c.4.8 Wiring, Terminal box and Power supply……………………………………………………………….17 1c.4.8.1 Wiring………………………………………………………………………………………………………………….17 1c.4.8.2 Power supplies……………………………………………………………………………………………………..18
   Contents: page 1 of 2
   5
   1c.4.9 Accessories…………………………………………………………………………………………………………..18 1c.4.10 Painting………………………………………………………………………………………………………………..19 1c.4.11 Spare partsand Special tools…………………………………………………………………………………19 1d Packing……………………………………………………………………………………………………………….19 1e Tests, inspection and test report (according to IEC 60076 and TIS 384)…………20 1f Losses in Bid evaluation……………………………………………………………………………………..22
   C2 Material and packing data to be given by bidder………………………………………..24 Note: Conditions for documentation and consideration………………………………………………..33
   APPENDIX 1
   (115-22 OR 33 kV POWER TRANSFORMER RATING AND FEATURES)………37 APPENDIX 2
   (ON LOAD TAP CHANGER SCHEMATIC DRAWING) …………………………………….39 APPENDIX 3
   (115 – 22 OR 33 KV POWER TRANSFORMER TYPICAL INFORMATION
   AND COMMANDS FOR CSCS) …………………………………………………………………………………41 APPENDIX 4
   (115-22 OR 33 kV POWER TRANSFORMERS BUSHING CURRENT
   TRANSFORMERS)………………………………………………………………………………………………………43 APPENDIX 5 (SMALL WIRING) …………………………………………………………………………………..45 APPENDIX 6 (Bill Of Material) ……………………………………………………………………………………….57
   C3 Schedule of Detailed Requirement 11 pages C4 Price Schedule 11 pages Drawing 3 pages
   Contents: page 2 of 2
   6
   PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 1 of 60
Invitation to Bid No.:
C Material equipment, and specifications for ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
C1 General material and packing instructions
Additional to the general instructions, the following shall be observed:
1a Scope
These specifications cover three-phase power transformers with on-load tap-changing equipment, air cooling system and accessories suitable for outdoor installation at 115 kV substations.
1b Standards
The transformers shall be manufactured and tested in accordance with the following standards:
International Electrotechnical Commission (IEC):
IEC 61869-1: 2007 Instrument transformers – Part 1: General requirements
IEC 61869-2: 2012 Instrument transformers – Part 2: Additional requirements for current transformers
IEC 61869-3: 2011 Instrument transformers – Part 3: Additional requirements for inductive voltage transformers
IEC 60076-1: 2011 Power transformers – Part 1: General
IEC 60076-2: 2011 Power transformers – Part 2: Temperature rise
IEC 60076-3: 2013 Power transformers – Part 3: Insulation levels, dielectric tests and external clearance in air
IEC 60076-5: 2006 Power transformers – Part 5: Ability to withstand short circuit
IEC 60076-7: 2005 Power transformers – Part 7: Loading guide for oil-immersed power transformers IEC 60076-10: 2001 Power transformers – Part 10: Determination of sound levels
IEC 60099-4: 2006 Surge arrester – Part 4: Metal-oxide surge arresters without gap for a.c. system IEC 60137: 2008 Insulated bushings for alternating voltages above 1 000 V
IEC 60156: 1995 Insulating liquids – Determination of the breakdown voltage at power frequency – Test method
IEC 60214-1: 2014 Tap-changers –Part 1: Performance requirements and test methods IEC 60296: 2012 Fluids for electrotechnical applications – Unused mineral insulating oils for transformers and switchgear
IEC 60529: 2013 Degrees of protection provided by enclosures (IP Code)
IEC 60666: 2010 Detection and determination of specified additives in mineral insulating oils II

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PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 2 of 60
IEC/TS 60815-1: 2008 Selection and dimensioning of high-voltage insulators intended for use in polluted conditions – Part 1: Definitions, information and general principles
IEC/TS 60815-2: 2008 Selection and dimensioning of high-voltage insulators intended for use in polluted conditions –Part 2: Ceramic and glass insulators for a.c. systems
IEC/TS 60815-3: 2008 Selection and dimensioning of high-voltage insulators intended for use in polluted conditions –Part 3: Polymer insulators for a.c. systems
IEC 61039: 2008 Classification of insulating liquids
Thailand Industrial Standard (TIS):
TIS 384: 2543 Standard for Power Transformers
And all other relevant standards, unless otherwise specified in these specifications.
PEA will also accept the transformers and accessories tested in accordance with the later edition of the above standards.
1c Principal requirements
1c.1 General
The transformers shall have a rated power of 50 MVA or 25 MVA.
The transformer with accessories shall be designed and constructed for outdoor installation on concrete foundations and operation under the general conditions stated in clause 1c.3 Site and service conditions. The transformers shall be designed and constructed for oil-purifying and vacuum oil filling at site.
The transformers shall be able to withstand dismantling, transportation and reassemble at site without damage (tank, windings and accessories).
Special care shall be taken to prevent moisture from getting into the main tank during transportation and storage. Suitable valves shall be provided to avoid draining oil from main tank or conservator when dismantling any device. All oil valves shall be flange type with suitable blind cover plates. Oil drain and filter valve shall be double flange type.
A gas relay (Buchholz relay) shall be supplied on the oil pipe between oil conservator and main tank. Flexible metallic oil pipe shall be used between the gas relay and oil conservator for convenience of assembly.
All indicating lamps used in local or remote cabinet shall be LED type.
1c.2 Design requirements
The transformers shall be provided with On-Load Tap-Changer (OLTC) on the primary side.
The transformers shall be capable of delivering rated MVA at all tapping positions.
The transformers shall be three-phase transformers, suitable for parallel operation, and meet the following requirement.
II

8
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 3 of 60
The transformer and accessories shall not cause interference with radio set or telephone equipment.
The average sound pressure level shall be measured in accordance with IEC 60076-10 and shall not exceed 77 dB.
1c.3 Site and service conditions
The main criteria can be applied globally everywhere in Thailand. Detailed specification will specify the ambient appropriated parameters for the involved area where the substation will be located.
Seismic activity None
Maximum wind speed ≈100 km/h
Maximum recorded rainfall 250 mm/day
Number of days with thunderstorm 100 days/year
Average rainfall 20 mm/day
Mean maximum annual relative humidity 94%
Mean minimum annual relative humidity 79%
Minimum daily relative humidity 17%
Maximum temperature of surfaces exposed to sunbeam 80oC
Mean minimum daily temperature 24oC
Maximum ambient temperature 40oC(1)
Minimum ambient temperature 11oC
(1) According to IEC 60271-1 over 40oC will be possible under special requirement.
1c.4 Equipments characteristics
1c.4.1 Transformers
1c.4.1.1 Requirements

1. Vector group: Dyn1 or YNyn0(d1) (see “C3 Schedule of detailed requirement”)
   The 115-22 kV transformer shall be of vector group of Dyn1 or YNyn0(d1).
   The 115-33 kV transformer having vector group of YNyn0(d1) shall have delta connected tertiary winding of 1/3 of the total transformer capacity. The rated tertiary voltage shall be 11 kV.
   One tertiary bushing shall be brought out for grounding purpose.
2. Short circuit impedance
   The short circuit impedance, at self-cooled rating as measured on the principle tapping of 115 kV at 75oC, shall be 7.5%.
   II

9
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 4 of 60
3. Limits of temperature rise
The limits of temperature rise, over 40oC, shall be as follows:
transformer Cooling method Method of temperature
Part of
Limits of
measurement
temperature rise
Winding ONAN, ONAF1, ONAF 2 Resistance method 55 K
Top oil ONAN, ONAF1, ONAF 2 Thermometer method 50 K
4. Core
Core shall be constructed of high quality non-aging, high permeability silicon steel. The steel shall be in thin laminations, annealed after cutting and rolled to insure smooth surfaces at the edges. Both sides of each sheet shall be insulated with a durable, heat-resistant baked enamel or varnish. The cores shall be rigidly clamped with positive locking devices to ensure adequate mechanical strength to support the windings and prevent shifting of laminations during shipment, installation and short circuit and also to reduce vibration to a minimum during operation.
Core sheet and core clamp shall be grounded in separate points.
Core shall be grounded at one point and a bushing shall be provided with removable link for possible measuring insulation between core and top of tank cover (2.5 kV).
5. Windings
The design, construction, and treatment of windings shall give proper consideration to all service factors, such as high dielectric and mechanical strength of insulation, coil characteristics, uniform electrostatic flux distribution, prevention of corona formation, and minimum restriction to free oil circulation.
The completed winding assembly shall be securely held in place so that there will be no derangement or deformation by stresses incident to shipment.
The completed winding assembly shall be securely held in place so that there will be no derangement or deformation by stresses incident to shipment. Applied pressure for winding clamping shall be controlled by applied torque or pressure on clamping bolts. Torque value or pressure on clamping bolts and the coil height shall be recorded and submitted for our reference.
The coils must be capable of withstanding movement and distortion caused by all operating conditions as specified in IEC 60076-7.
To increase transformers capability of withstanding the diagram forces under short-circuit conditions, modern technology in design and construction shall be applied (Pre-drying and precompressing of the winding before installing in tank)
II

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PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 5 of 60
6. Tank
The tank shall be capable of withstanding, without leakage or permanent distortion, an internal gas pressure of 101,325 Pa and a vacuum of 76 cm of mercury, and shall be designed and constructed for vacuum filling in the field.
Cover shall be welded to the tank to avoid oil leakage.
The transformer tank shall be designed without pockets wherein gas may collect.
All valves, fittings, and piping shall be designed and constructed for vacuum filling.
The tank shall also have suitable jacking pads and pulling lugs. The tank shall be provided with a fabricated or structural steel base designed and built to allow skidding or moving on rollers in either direction.
Flat base plates are not acceptable.
The transformers shall be equipped with manholes and/or hand holes of suitable size to make installation and maintenance easy. Cover for inspection openings bushings, hand holes etc. located directly on the tank cover shall be provided with adequate gas stoppers.
It must be possible to remove any bushing without removing the tank cover.
In order to prevent tank deformation during operation, pressure relief devices with manually reset and visual indicator shall be mounted directly on the tank cover for pressure release static pressure adjustment of such devices shall be less than hydraulic test pressure.
7. Insulating oil
The insulating oil furnished for use in transformer and tap changer compartment shall be new pure mineral oil prepared and refined especially for use in transformers. The transformers shall be delivered with initial oil filling remaining in the core and windings after factory testing.
The reserved oil shall be provided at least ten (10) per cent of total filled amount and contained in steel drum(s) which shall become the property of PEA by free of charge.
The quality of the insulating oil shall be in compliance with IEC 60296 or equivalent. The oil shall be classified as uninhibited insulating oil class 1 according to IEC 60296.
8. Oil preservation system
∙ Conservator system
Conservator system shall be of air-bag type provided with Buchholz relay at the highest point.
Magnetic type oil level indicators showing the full level range shall be fitted to all oil vessels,
being clearly marked with the normal level. All conservator compartments shall be designed in
such a manner that at the same oil temperature all oil levels are nearly equal. The conservator
vessels shall be fully vacuum proof and designed in such a way that it can be completely drained
by means of the drain valve, when in service.
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PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 6 of 60
Each conservator vessel shall be furnished with a cleaning opening. A vacuum equalizing valve
between the conservators shall be provided at a convenient floor height. Conservator tank with
low-profile design shall be located at a slightly higher level than the transformer tank in such a
position that will not obstruct the maintenance of the tap changer.
∙ Main conservator tank
The main conservator tank shall be capable of withstanding, without leakage or permanent
distortion, an internal gas pressure of 101,325 Pa and a vacuum of 76 cm of mercury, and
shall be designed and constructed for vacuum filling in the field.
Main conservator tank shall be sized to accommodate the change in oil volume, which will
occur, between an ambient air temperature of zero degree C and an ambient air temperature of
40-degree C with the transformer operating at full load. The conservator tanks shall slope
towards one end with the drain valve located at the lower end.
A hand-hole for access to the interior of the conservator and a filling pipe with weather-tight
cap shall also be provided. Each conservator vessel shall be fitted with breather in which silica
gel has been filled as a dehydrating agent. The breather shall be connected to the air
expansion pipes. A suitable tool for removing the cap and operate the valve, shall be fitted to
the tank by a fly-nut at an accessible position in a convenient floor height. In view of
excessive humidity, breathers shall be larger in size and shall be provided with oil trap. The
silicagel filling capacity of each breather shall be at least 1.5 kg for the OLTC conservator and
4 kg for main conservator. The silicagel breathers as well as all filling and draining devices
shall be rigidly fastened at an accessible position in a convenient floor height.
9. Bushings
Bushings shall conform to the requirement of IEC 60137 for HV and IEC or DIN for MV.
The primary bushing (H0, H1, H2, H3) except neutral bushing shall be condenser bushing, draw lead oil-filled, gas-sealed type, with capacitance test tap and oil level gauge.
The secondary bushing shall be installed in vertical on top of main tank.
The insulation level of line bushings shall be equal to or greater than the insulation level of the winding to which they are connected. The color of all porcelain insulators shall be brown; and each porcelain shall be one (1) piece. Primary and secondary neutral point shall be brought out by separate insulated bushing with rated current the same as the line bushing. Insulation level of neutral bushing shall be equal or greater than insulation specified in APPENDIX 1.
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PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 7 of 60
Bushing shall locate as shown in the sketch below:
Right Hand Left Hand Right Hand Left Hand
High-Voltage Side High-Voltage Side
YNyn0(d1) HO H1 H2 H3
Dyn1 H1 H2 H3
X0 X1 X2 X3
X0 X1 X2 X3
Low-Voltage Side Low-Voltage Side
10. Line terminals
The line and neutral bushing terminals shall be for heavily polluted atmosphere and fitted with terminal pads. The terminal pads shall be of high conductivity material (preferably bronze, tin plated), each pad shall be drilled with four (4) holes in accordance with NEMA standards (14 mm holes on 44.5 mm center hole spacing).
The low-voltage side shall be designed as stated in “C3 schedule of detailed requirement”.
1c.4.1.2 Ratings

1. Creepage distance of outdoor insulators
   A minimum creepage distance, from live parts to ground, of outdoor bushing and insulators, shall be as follows:
   For 115-22 kV transformers

• 115 kV equipment : 3,070 mm
• 22 kV equipment : 600 mm
  For 115-33 kV transformer
• 115 kV equipment : 3,810 mm
• 33 kV equipment
  when installed without cable box : 1,110 mm
  when installed in cable box : 900 mm

2. Rating and Features
   For rating and features refer to attached APPENDIX 1.
   II

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PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 8 of 60
1c.4.2 On-Load Tap-Changer (OLTC)
1c.4.2.1 Requirements
The OLTC shall be manufactured and tested in accordance with IEC 60214-1 or equivalent.
The OLTC shall be high speed resistor type.
The OLTC shall be in-tank or tank mounted type.
The OLTC shall be vacuum technology.
The OLTC manufacturer shall be:

• MASCHINENFABRIK REINHAUSEN (MR)/Germany; or
• ABB/Sweden
  Only for the transformer having primary winding of delta-connected, on-load tap changing shall be done at the middle of the transformer winding.
  Removable bolted cover shall be provided for access to the arcing switch without having to open the main tank or lowering the oil in the main tank.
  The tap changer head shall be provided with an integrated pressure relief diaphragm (rupture disk) or other relief valve provided by OLTC manufacturer.
  The protective relay and valve mounted into the oil pipe between the tap changer and oil conservator responding to the oil-flow from the OLTC oil compartment toward the oil conservator shall be provided. Overpressure relay for protection of load tap changer is also accepted.
  1c.4.2.2 OLTC compartment
  The contact life of the moving and fixed contacts of the on load tap selector switch, at the rated current shall be 500,000 operations minimum. Mechanical life shall be more than 1,000,000 operations.
  The OLTC shall have an inspection interval, and at the maximum rated current of at least five (5) years of service or not less than 50,000 tap change operations for oil tight enclosure, and at least fifteen (15) years and not less than 150,000 tap change operations for vacuum type, which ever is earlier.
  OLTC shall be able to be loaded up to 120% of transformer rating power.
  The oil for the OLTC shall be in a separate compartment, having separate oil level gauge and dehydrate breather.
  The OLTC shall be provided with:

1. Pressure-relief device with a pressure control contact for tripping at a preset pressure
2. Protective relay or pressure relay with tripping contact
3. Oil conservator
4. Dehydrating breather with silicagel of not less than 1.5 kg
5. Drive shaft
6. Motor drive unit
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PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 9 of 60
1c.4.2.3 Operation
Refer to schematic drawing in APPENDIX 2 attached.
The OLTC shall be suitable for automatic and manual operation.
Automatic tap changing shall be operated by receiving signal from voltage regulating relay. Manually tap changing shall be operated either by electrical (push buttons) or mechanical (driving handle) operation.

• When the OLTC is being driven by hand, the electrical system shall be automatically disconnected, hand crank or hand wheel shall be furnished.
• When the OLTC is electrically operated, it can be either by remote operation performed by CSCS from control room or Area Control Center or Local operation (push buttons).
  The motor drive unit shall operated on three-phase 400 V AC 50 Hz and be provided with motor protection, i.e., open-phase, under voltage, overload, reverse rotating field, etc., and circuit-breaker to connect and disconnect the power supply to motor.
  For in tank OLTC, a manhole shall be installed on side of main tank and shall be provided for easy maintenance.
  1c.4.2.4 Driving mechanism
  OLTC driving mechanism housing shall be weatherproof type, IP 54 according to IEC 60529 with electrically heated to prevent from moisture mounted on the side of transformer, and equipped with at least following equipment:

1. Raise/Lower control switch
2. Transmitter for tap position
3. Operation counter
4. Local tap position indicator readable from outside without any obstruction
5. Limiting device to prevent from overreaching extreme tap positions
6. Equipment to operate remotely
7. Indicator when tap changer is in operation
8. Convenient outlet, for single phase 230 V and lighting with door switch
9. Heater controlled by On-Auto-Off selector switch, hygrostat shall be used for auto mode.
10. Hand crank or hand wheel for manual operation, interlocked with motor control
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PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 10 of 60
1c.4.3 Cooling equipment
1c.4.3.1 Requirements
The fans shall be automatically or manually controlled.
Fans shall be automatically controlled by a transformer winding temperature relay and shall be furnished with all necessary control and protective devices. It shall be possible to remotely control the cooling system either from the local panel of the remote control cabinet or from CSCS at the control room.
Each transformer shall be furnished and equipped with a sufficient number of radiators and cooling equipment to operate as a self-cooled and forced-cooled unit at the specified ratings.
The forced-cooled ratings will be obtained by the use of fans Class ONAN/ONAF1/ONAF2.
Radiators shall be removable type. Each radiator connection shall be equipped with a valve to permit removal of the radiator for maintenance without draining the oil out of the tank. Oil tight blank flange shall be provided for each valve, for use when radiators are detached. Each radiator shall have lifting eye(s), an oil drain, and a vent.
The loss of any fan shall reduce the output of the transformer by not more than twenty (20) per cent, with temperature rises maintained within the specified limits.
Fan motors shall be designed for three phase 400/230V 50 Hz power supply and totally enclosed, weatherproof, squirrel cage and full-voltage starting.
The motors shall have individual thermal protection installation, shall be suitable for tropical hot and humid climate.
The fans shall be made of aluminum alloy or stainless steel, balanced dynamically and equipped with hot dipped zinc galvanized guards.
The fans shall be divided in two groups operated by the two steps winding temperature relays.
Selection of either group of fan to be the first to operate will be provided at the local control board. The fan control system will be able to operate in such a way that when other group operates at the same time, when a load decrease occurs, the group which stops first will be the one which has started first.
Cooling local control cabinet shall be weatherproof type, IP 54 according to IEC 60529. The fan motors shall have necessary protection, i.e., open-phase, under voltage, overload, etc.
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PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 11 of 60
1c.4.3.2 Cooling local control
A local control for cooling system shall be equipped in local control cabinet with at least the following equipment:

1. Automatic/Manual selector switch
2. Local/Remote selector switch
3. Start-Stop control switch(es) of each group of fan.
4. Selector switch for selecting either group of fan to be the first group to operate.
5. Indicating lamps showing the operation of motor protecting equipment.
6. Circuit-breaker for connect and disconnect power supply of motors.
7. Auxiliary contact for operation and monitoring of cooling system by CSCS.
   1c.4.3.3 Cooling remote control
   A remote control for cooling system shall be equipped in remote control cabinet with at least the following equipment:
8. Automatic/Manual selector switch
9. Start – Stop control switch(es) of each group of fan
10. Indicating lamps showing the operation of motor
    1c.4.4 Control cabinet
    1c.4.4.1 Local control cabinet
    A local control cabinet shall be weatherproof type, IP54 according to IEC 60529, and shall be opaque (including door) for protecting inside equipment against ultra-violet radiation, mounted on the side of the transformer, and equipped with at least the following equipment:
11. Local/Remote selector switch
12. Indicating lamp for OLTC operation
13. Alarm bell and on/off switch
14. Voltmeter, for reading the output voltage, in kV
15. Ammeters for reading the output current of each phase
16. Instantaneous overcurrent relays, self reset, these three overcurrent relays shall have the drop off to pick up ratio of not less than 90%, in order to prevent tap change operation during a short circuit which would too greatly stress the contacts of the diverter switch. The function of protection shall be arranged to block the operation of the OLTC in case a short circuit occurred before or during tap change in progress.
17. Heater controlled by On-Auto-Off selector switch, hygrostat shall be used for auto mode.
18. Convenient outlet, for single phase 230 V AC power and lighting with door switch
19. Terminal block with at least 10% spare terminals
    All cables shall enter the cabinet from the bottom through cable glands mounted in the bottom gland plate (non-magnetic metal).
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PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 12 of 60
1c.4.4.2 Remote control cabinet
A remote control cabinet shall be indoor type, The outside dimensions of the remote control cabinet shall be 800 mm wide, 610 mm deep and the height shall be 2,250 mm plus a 50 mm channel bases. Finished panel surfaces shall be free from waves, bellies, or other imperfections. Exterior and interior surfaces shall be cleaned by sanding and steam cleaning, ground smooth, filled, primed, sanded and shall be finish-painted inside and outside with gray color (RAL 7032).
A remote control cabinet shall be equipped with at least the following equipment:-

1. Automatic/Manual selector switch
2. Individual/Parallel
3. Operation counter
4. Local/Remote selector switch
5. Indicating lamp for OLTC operation
6. Raise and lower control switches for manual control
7. Tap position indicator and contact assembly for sensing the position of tap changer suitable for use in conjunction with CSCS.
8. Automatic voltage regulating device. This device shall have provision for setting voltage, voltage band width, time delay, line drop compensation or load current controlled and test facilities to check operation of device.
9. Voltage monitoring circuit, which shall indicate alarm in case of voltage lower or higher than limit caused by the failure of automatic voltage regulating relay.
10. Alarm bell and on/off switch
11. Voltmeter, for reading the output voltage, in kV
12. Ammeters for reading the output current of each phase
13. Contact assembly for sensing the position of tap changer suitable for use in conjunction with CSCS. 14. Annunciator panel
14. Heater, controlled by On-Auto-Off selector switch, hygrostat shall used for auto mode.
15. Circuit breaker for control and power supply circuits. Circuit breaker for motor protection circuit. 17. Convenient outlet, for single phase 230 V AC power and lighting with door switch.
    All cables shall enter the cabinet from the bottom through cable glands mounted in the bottom gland plate (non-magnetic metal).
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PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 13 of 60
1c.4.4.3 Remote controlled functions
The functions at least remotely controlled by CSCS are listed in APPENDIX 3 attached.
1c.4.4.4 Annunciator panel
An annunciator panel shall be provided to indicate individual defects of each transformer. An annunciator panel shall consist of a compact group of alarm modules, complete with display unit of back-lights, flasher and auxiliary relays. Push buttons as specified shall be provided near the display unit. The alarm annunciator assemblies shall be dust-proof, fully tropicalized and flush-mounted in the remote control cabinet.
The alarm annunciator units shall be of electronic solid state design. Printed circuit card modules of the plug-in type shall be used.
The display unit shall consist of individual nameplates. Each nameplate shall be inscribed with the specified legend, describing the fault condition to be indicated.
The nameplate shall be white translucent, the legend shall be engraved in black letters. Each nameplate shall be provided with two (2) lamps in parallel.
The operation of the alarm annunciator system shall be as follows:

• When an alarm contact is initiated the audible warning shall sound continuously and the nameplate concerned shall be illuminated by a flashing light.
• An “ACKNOWLEDGE” push-button shall be provided which when pressed, shall silence the audible signal and cause the nameplate to remain illuminated steadily.
• The alarm circuit shall be designed to retain the indication after the reopening of the initiating contact, requiring to press a separate “RESET” push button to cancel the alarm.
• A “TEST” push button shall be fitted close to “ACKNOWLEDGE” and “RESET” buttons, to illuminate all nameplates on the display unit for as long as the “TEST” button is pressed.
  The operation of the “ACKNOWLEDGE” button shall not preclude the receipt of further indications giving audible alarm and visual indication. Horn and nameplate lamps shall be ready to sound and flash respectively for any other abnormality.
  Operation of an annunciator lamp shall neither interfere with nor cause false operation of any other annunciator lamp whether initiated simultaneously or in sequence.
  The audible warning shall be given by the substation alarm horn. Each initiated alarm shall operate this horn.
  For any defect which requires trip initiation, the contact of the corresponding transformer’s protective relays shall be connected to terminal blocks to connect to PEA’s auxiliary tripping relay. The fault indication on annunciator shall be of at least as follows:

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PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 14 of 60
Lists of information available at remote control cabinet
No. Fault Abbreviation Tripping contact
1 Transformer oil temperature rise (Alarm) TR. OIL TEMP. ALARM NO 2 Transformer oil temperature rise (Trip) TR. OIL TEMP. TRIP YES 3 Transformer low oil level TR. OIL LEVEL NO 4 Transformer pressure relief device operation TR. PRES. RELIEF YES 5 Transformer winding temperature rise (Alarm) TR. WIND. TEMP. ALARM NO 6 Transformer winding temperature rise (Trip) TR. WIND. TEMP. TRIP YES 7 Buchholz relay operation for main tank (Alarm) TR. BUCH. ALARM NO 8 Buchholz relay operation for main tank (Trip) TR. BUCH. TRIP YES 9 Oil surge relay operation for main tank, if any TR. OIL SURGE. TRIP YES 10 Diverter switch oil level down DIV. SW. OIL LEVEL NO 11 Diverter switch pressure relief device operation DIV. SW. PRES. RELIEF YES 12 Protective relay or Pressure relay operation for diverter
DIV. SW. PRO/PRESS. TRIP YES
switch (Trip)
13 Parallel Control Failure PARALLEL CONTROL FAILURE NO 14 OLTC overcurrent relay operation OLTC OVER CURRENT NO 15 Change-delay of OLTC TAP CHANGE DELAY NO 16 Circuit-breaker for OLTC motor failure OLTC MOTOR BKR. NO 17 Circuit-breaker for fan motor failure FAN MOTOR BKR. NO 18 Fan motor overload FAN THERM. RELAY NO 19 Circuit-breaker for oil motor failure, if any OIL MOTOR BKR. NO 20 Oil motor overload, if any OIL THERM. RELAY NO 21 Reverse phase operation AC FAILURE NO 22 AC control power source failure AC CONTROL FAILURE NO 23 DC control power source failure DC CONTROL FAILURE NO
1c.4.5 Safety factor
Lifting, moving, and jacking facilities shall be designed to provide a safety factor of five (5). This safety factor is the ratio of ultimate stress of the material used to the working stress. The working stress is the maximum combined stress developed in the lifting facilities by the static load of the component being lifted.
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PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 15 of 60
1c.4.6 Instrument transformers
1c.4.6.1 Current transformer

1. General Design
   The current transformers, not elsewhere specified, shall be bushing type on primary winding, secondary winding and neutral. They shall be removable from the transformer tank without removing the tank cover. All secondary leads of current transformers shall be brought to short circuiting type terminal blocks.
   Bushing current transformer, protection core shall have adequate output to meet the total burden of the equipment connected to them. Their characteristics, thermal, voltage, overcurrent performances, internal resistance and accuracy shall be of sufficient rating for the satisfactory operation of their associated equipment and wiring.
   It will be Bidder responsibility to calculate accuracy and burden. The calculation shall be submit with the bid proposal to Authority for approval.
   The current transformers shall be connected to other switchgear components in such a way that undue mechanical stress cannot be exerted on the transformer winding.
   The current transformers shall be designed and mounted to withstand the mechanical and thermal stress caused by short-circuits.
   The arrangement of the terminal blocks shall make it impossible, under any circumstances, accidentally to open-circuit the secondary circuits. All terminal markings on the primary and secondary terminals shall be in accordance with the requirements of IEC 61869-1 and IEC61869-2 and shall be such as not to be altered by external agents.
2. Ratings
   Ratings of current transformers are listed in APPENDIX 4 attached.
3. Tests
   The Contractor shall be responsible for ensuring that the following test have been done and carried out in accordance with IEC61869-1 and IEC61869-2, otherwise specified.
   ∙ Type Tests

• Short-time current tests
• Temperature rise test
• Determination of errors
• AC voltage test
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PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 16 of 60
∙ Routine Tests

• Verification of terminal markings
• Power frequency withstand test on secondary windings
• Power frequency withstand tests between sections
• Inter-turn overvoltage test
• Power frequency withstand test on primary winding
• Partial discharge measurement
• Measurement of ratio error and phase angle
• Excitation curve check
• Internal burden measurement
  1c.4.6.2 Voltage transformer
  A voltage transformer shall be provided for voltage regulation. It shall be installed on the transformer tank near its secondary bushings in the cable box.
  Parallel operation shall be done using circulating current method.
  Due to severe climatic conditions it shall be cast resin and outdoor type.
  Line terminal connectors, on primary bushings of voltage transformer shall be solderless clamp type (using bolts and nuts), of high conductivity bronze and hot-tin-dipped or better and suitable for aluminum and copper conductors diameters 9.0-12.69 mm (size 50-95 mm2).
  Rating will be as specified in the following table:
  Voltage
  Voltage transformers Ratio
  (kV) NO. of core Class Burden
  factor
  (VA)
  Voltage Transformer for
  22 : 0.11 1 0.5 50 1.2
  22 kV system
  continuous
  Voltage Transformer for
  33 : 0.11 1 0.5 50 1.2
  33 kV system
  continuous
  Burden is specified for simultaneous use.

1. Tests
   The Contractor shall be responsible for ensuring that the following test have been done and carried out in accordance with IEC61869-1 and IEC61869-3, otherwise specified.
   ∙ Type Tests

• Temperature rise test
• Short-circuit withstand capability test
• Lightning impulse voltage test
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PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 17 of 60
- Switching impulse voltage test

• Determination of errors
  ∙ Routine Tests
• Verification of terminal marking
• Power frequency withstand test on secondary windings
• Power frequency withstand test on primary windings
• Power frequency withstand test between sections
• Determination of errors
• Capacitance measurement
• Measurement of dissipation factor
  1c.4.7 Earthing
  The exposed noncurrent-carrying parts of the transformer, control cabinet, and metal frames of instruments used, shall be earthed. Earthing bridges shall be provided between tank and tank cover, conservator tanks and tank cover, head of OLTC and tank cover, local control cabinets and tank, control housing of motor drive and tank, etc. All earthing bridges shall have a suitable cross-section and be painted.
  Ground pads, for transformer tanks, shall be of two (2) copper-faced steel pads or two (2) stainless steel pads without copper facing. Ground pads shall be suitable for copper conductor diameter 12.6 mm (size 95 mm2). The thickness of the copper facing shall not be less than 0.4 mm.
  Ground terminals for remote control cabinet shall be suitable for copper conductor diameter 12.6 mm (size 95 mm2)
  1c.4.8 Wiring, Terminal box and Power supply
  1c.4.8.1 Wiring
  The wiring between the devices in the transformer shall be run in rigid metal conduits. Wiring by steel wire armored cables is also accepted.
  The conduit shall be suitably connected to the transformer accessories and the terminal box.
  The wiring of the oil pressure relief devices shall be run in flexible metal conduit or shall be armored cable. The cables connected to the pressure relief devices shall withstand continuous temperature up to 100 °C. Connections of trip contacts and alarm contacts of the pressure relief devices shall be installed in cable boxes for environment protection (see drawing No.SA4-015/50005 attached).
  Terminal boards shall be mounted in the terminal box, for the connection of the internal wiring to external circuits. The 22 kV terminal boxes shall be openable on the top.
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PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 18 of 60
Barriers shall be provided in the terminal box to separate the 400 V circuits from lower-voltage circuits. The bottom of the terminal box shall be equipped with removable blank cover plates. Sufficient space heater, hygrostat and lighting shall be provided in the control cubicles.
All the cable shall be fixed on support to prevent from any stress on transformer devices and accessories.
For additional information refer to attached APPENDIX 5.
1c.4.8.2 Power supplies
Power supplies for operating devices and control will be 125 V DC and 400/230 V AC 50 Hz.
1c.4.9 Accessories
Each transformer shall be at least furnished and equipped with the following accessories:

1. Bushing with line terminal pads
2. Oil conservators, for main tank and diverter switch compartment
3. Diaphragm or rubber bag type oil preservator
4. Dehydrating breathers (Flange of Dehydrating breathers shall be shown in Drawing No. SA4- 015/50003 attached)
5. Double float Buchholz relay with alarm and trip contacts
6. Oil surge relay
7. Pressure relief devices
8. Dial oil temperature indicator *
9. Dial oil level indicator for main tank
10. Dial winding temperature indicator for each phase *
11. Dial oil level indicator for OLTC
12. Pressure-Vacuum gauge (for used during transportation)
13. Upper filter valve, globe type or stainless steel ball type
14. Oil drain and filter valve, globe type or stainless steel ball type
15. Oil sampling valves
16. Sludge drain valve (Double Flange Type DN 40, Flange of Sludge drain valve is shown in Drawing No. SA4-015/50004 attached)
17. Lifting lugs
18. Jacking bosses (pads)
19. Handhole and/or manhole on cover
20. Cover lifting eyes
21. Pulling eyes
22. Nameplate with connecting diagram
23. Ladder
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PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 19 of 60
24. Plate of 400 x 200 mm, provided for painting PEA serial No..
25. The supplier shall provide the spare of alarm contacts, control switch contacts and wiring to the terminal blocks of local control cabinet for connecting to DIM of the computer-based substation control system (CSCS).

• Monitoring system for power transformer (Item 8 and 10) shall be of conventional type completing with all interfacing required by CSCS system (4-20 mA for interfacing to CSCS system).
  1c.4.10 Painting
  Surfaces in contact with transformer oil shall be finished with oil-resistant paint. Other surfaces shall be painted with a primer coat and not less than two (2) finish weather resistant coats, or better the final coat color shall be grey color (Code RAL 7036).
  1c.4.11 Spare parts and Special tools
  Bidders have to quote spare parts as state in “C3 Schedule of detailed requirement”, recommended spare parts, and special tools for installation and maintenance with separate prices.
  1d Packing
  Each individual package (e.g. box, crate, case, bundle, or piece of loose material) of each shipment shall be painted tagged and/or marked according and corresponding to the Invoice and Packing list for easy identification.
  For the supply of more than one (1) transformer, parts belong to different transformers shall not be packed in the same package. The packages shall be lettered and numbered by the supplier to designate transformer-package number/total number of the packages of each transformer being shipped; for example: two (2) transformers are supplied,
  A-1/5, A-2/5, ……., A-5/5 for the first transformer.
  B-1/7, B-2/7, …….., B-7/7 for the second transformer.
  Spare parts and special tools, if ordered, shall be separately packed in other packages on which the words “SPARE PARTS” and “SPECIAL TOOLS” package number/total number of the packages being shipped shall be marked.
  Transformer tank, radiators, and oil may be shipped separately, but core and winding in the transformer tank shall be shipped in oil.
  For highway transportation, the largest package shall be limited as follows:
  Width : 3.5 m
  Length : 5.8 m
  Height : 3.6 m
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PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 20 of 60
1e Tests, inspection and test reports (according to IEC 60076 and TIS 384)

1. Special requirement - Ability to withstand short circuit
   The transformers shall be designed and constructed to withstand without damage by the thermal and dynamic effects of the external short circuit in accordance with the IEC 60076-5, the ability to withstand the dynamic effects of short circuit shall be demonstrated either:
2. By testing the identical transformer (purchased transformer). In this case the bidders have to submit the short circuit test report with the bid, or
3. By calculation with the reference transformer. In this case the bidders have to submit the short circuit test report of the reference transformer and all necessary information according to IEC
   60076-5 with the bid, the reference transformer which passed the short-circuit test shall have
   ratings of not less than 110 kV and 50 MVA, or
4. By using the manufacturer’s design rules according to IEC 60076-5. In this case the bidders have to submit calculation report and all necessary information from licenser according to IEC
   60076-5 with the bid and after signing contract, the contractor has to submit the short circuit
   test report of the purchased transformer before PEA acceptance. This condition applied to the
   local manufacturers who produce the power transformers under license of a major reputable
   principal manufacturer who have no less than twenty (20) year experience in manufacturing of
   power transformers.
   The purchased or reference transformers shall be passed the short-circuit withstand test according to IEC 60076-5 conducted or inspected by the acknowledged independent testing laboratories.
   Any bid which does not comply with this requirement, shall not be considered.
5. Reports
   ∙ The bidders shall submit, with the bid, the short-circuit test report, calculation report and/or all necessary information mentioned in 1. Special requirement.
   ∙ The bidders shall submit the manufacturer’s own type test report(s) of the power transformers having rating of not less than 110 kV and 50 MVA with the bid. The type test report(s) shall
   have details to show that the manufacturer has manufactured the power transformer of such
   rating and have successfully passed all type tests or design tests in accordance with the
   applicable standards.
   ∙ Standard factory tests shall be made in accordance with routine test stated in the reference standard and they shall be performed in accordance with the procedure specified.
   ∙ Any bid which does not comply with this requirement, shall not be considered.
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PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 21 of 60
3. Routine tests
∙ Transformer set and OLTC
The following tests should be carried out as a minimum:
Test items Unit tested

• General Inspection of external construction All units
• Checking of vector group
  All units
• Dissolved gas-in-oil analysis before routine tests, after routine tests
  All units
• Pressure and leakage test on assembled transformer
  All units
• Full wave lightning impulse test for the line terminal (LI) All units
• Measurement of winding resistance at all tap positions (test current of min.
  All units
  20 A DC)
• Measurement of voltage ratio at all tap position and check of voltage vector
  All units
  relationship
• Measurement of short circuit impedance (principal and both extreme taps)
  All units
  and load losses
• Measurement of Cooling fan loss
  All units
• Measurement of no-load losses and measurement of the excitation current
  All units
  at 90%, 100% and 110% of rated voltage on the high voltage connections
• Measurement of zero-sequence impedance.
  All units
• Induced over voltage test (at tap position “9”) with PD measurement All units
• Applied voltage test (AV) All units
• Measurements of the capacitances and dielectric dissipation factors All units
• Measurement of the acoustic sound levels at ONAN
  One unit*
  (0.3 m) and ONAF2 (2 m) according to IEC 60076-10
• Measurement of the insulation resistance All units
• Measurement of core to ground resistance All units
• Test on load tap-changers oil filter unit and cooling equipment All units

• The test shall be performed on one unit of each transformer type being supplied.
  ∙ Oil filter unit
  The following tests should be carried out as a minimum:
  Test items Unit tested

• General inspection All units
• Operation test All units
• Oil leakage test at the oil pressure 6 bar for 30 minutes (oil filter tank only) All units
  II

27
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 22 of 60
4. Type tests and Special test for transformer set and OLTC
∙ The following tests should be carried out
Test items

• Measurement of all physical properties and dielectric strength of the insulation oil
• Temperature rise tests
• Dissolved gas-in-oil analysis before dielectric tests, prior to temperature rise tests and after
  temperature rise tests
• Chopped wave lightning impulse test for the line terminals (LCI)
• Lightning impulse test for the neutral terminals (LCN)
  ∙ Impulse voltage withstand test (including neutral terminal) and temperature rise test shall be required, one unit per each rating as stated in IEC 60076-2 and IEC 60076-3.
  The costs of all tests and reports shall be borne by the Contractor.
  1f Losses in Bid evaluation

1. Losses
   The guaranteed losses plus positive tolerance, for each transformer unit, shall not be more than the figures (upper limit) in the table below:
   No-load loss plus positive
   Load loss plus positive tolerance plus
   Transformer Rating
   tolerance at 115 kV rated
   Total load of cooling equipment plus
   (MVA)
   voltage (C) (kilowatts)
   positive tolerance (D+E) (kilowatts)
   30/40/50 up to 25.5 up to 150
   15/20/25 up to 15.0 up to 100
2. Bid evaluation
   The evaluation of transformer will be based on price and cost of energy losses, the following formula will be used:
   A = B + 120,000 C + 80,000 (D+E)
   Where:
   A = Evaluated cost of transformer in Baht
   B = Unit cost in Baht
   C = No load loss plus positive tolerance, at 115 kV rated voltage, in kilowatts
   D = Load loss plus positive tolerance, at full load of 50 MVA for 50 MVA power transformer and of 25 MVA for 25 MVA transformer, at 115 kV rated voltage, in kilowatts
   II

28
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 23 of 60
E = Total load of cooling equipment plus positive tolerance, at full load of 50 MVA for 50 MVA transformer and of 25 MVA for 25 MVA transformer, at 115 kV rated
voltage, in kilowatts
∙ For 50 MVA transformers
If no-load loss plus positive tolerance, C, at 115 kV rated voltage, for each transformer unit is
lower than 23 kW (lower limit), PEA will use 23 kW in evaluation
If load loss plus positive tolerance plus Total load of cooling equipment plus positive
tolerance, D+E at 50 MVA, at 115 kV rated voltage, for each transformer unit, is lower than
135 kW (lower limit), PEA will use 135 kW in evaluation.
∙ For 25 MVA transformers
If no-load loss plus positive tolerance, C, at 115 kV rated voltage, for each transformer unit is
lower than 13.5 kW (lower limit), PEA will use 13.5 kW for evaluation.
If load loss plus positive tolerance plus Total load of cooling equipment plus positive
tolerance, D+E, at 25 MVA, at 115 kV rated voltage, for each transformer unit, is lower than
90 kW (lower limit), PEA will use 90 kW in evaluation.
∙ Exceed losses and compensations, in acceptance
If the average of actual No-load loss plus positive tolerance (C) of all transformers in the same
MVA-rating exceeds the value quoted (see Page 27 of 60), the Contractor shall compensate to
PEA at Baht 132,000.-/kW for the exceeding watt-loss of all transformers.
If the average of actual load loss plus positive tolerance plus total load of cooling equipment
plus positive tolerance (D+E) of all transformers in the same MVA-rating exceeds the value
quoted (see Page 27 of 60), the Contractor shall compensate to PEA at Baht 88,000.-/kW for
the exceeding watt-loss of all transformers.
The individual transformer which has any actual loss, C or (D+E), exceeding 10% of the
value quoted (see Page 27 of 60) shall not be accepted.
II

29
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 24 of 60
C2 Material and packing data to be given by bidder
The bidder has to submit the following data and details of transformers and accessories with the bid:
2a Performance data and guarantee for transformers
(Vide Pages 26 to 32 of 60)
2b Drawings of overall transformer and radiators with dimensions in mm, showing particulars of construction.
2c Details, catalogues and/or drawings with dimensions in mm, of the following equipment: 1. Bushings
2. Line terminal pads, with description of material used for the component parts
3. Oil conservators
4. Dehydrating breathers
5. Buchholz relay and oil surge relay
6. Pressure relief devices
7. Dial type thermometers
8. Dial type oil level gauges
9. Pressure-vacuum gauge
10. Valves
11. Nameplate with connection diagram
12. Ground pad
13. Ground terminals for remote control cabinets
14. Current transformers
15. Voltage transformer, line terminal connectors, and nameplate
16. On-load tap-changer, and motor drive unit
17. Local control cabinet for OLTC and cooling equipment
18. Remote control cabinet for OLTC and cooling equipment
19. Voltmeter
20. Ammeter
21. Siren or horn
22. Over current relay
23. Timer
24. Voltage regulating relay and parallel checking device
25. Line drop compensator
26. Annunciator panel
27. Cooling fan(s)
II

30
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 25 of 60
28. Circuit-breakers
29. Surge arresters
30. Cable termination kit
31. Spare parts.
32. Special tools
33. Etc.
2d Electrical wiring and connection diagrams of operating and control circuits
2e Specifications of insulating oil
2f Details of painting
2g Shipping and transportation sketches
2h List of routine tests
2i List of spare parts with itemized prices
2j List of special tools for installation with itemized prices
2k Record of supply and/or license agreement
2l Short circuit test report, calculation report and/or all necessary information
2m Packing details
Packing method (describe packing materials)
Number of units, pieces, or sets in each package
Dimensions (L x W x H) of each package in cm
Volume of each package in m3
Gross weight of each package in kg
Number of packages
If several packages are contained in one big case, further details, are required:
Number of packages in each case
Dimensions of each case in cm
Volume of each case in m3
Gross weight of each case in kg
Number of cases
II

PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION
Approved date: 23/09/2559
Specification No.: RTRN-014/2559

…………………………………………………………………………………………………………………….
:
…………………………………………………………………………………………………………………….
:
…………………………………………………………………………………………………………………….
:
3 phases………………………………………………………………………………………………………..:
50 Hz……………………………………………………………………………………………………………:
…………………………………………………………………………………………………………………….
:
(Yes/No) ………………………………………………………………………………………………………:
…………………………………………………………………………………………………………………….
Rated secondary voltage (kV) :
…………………………………………………………………………………………………………………….
:
Performance data and guarantee of: II
Invitation to Bid No.:
Transformer 2a.1
Manufacturer’s name
Country of origin
Type or Model
Number of phases
Rated frequency (Hz)
Vector group
Continuous duty

Voltage tappings
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION
115
ONAF1 40 20
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
Approved date: 23/09/2559
Specification No.: RTRN-014/2559

ONAN 
30 
15 




























kV 
- 
MVA 
% 

%
%
%
K
K
kW
kW
A
%
kW
kV peak
kV r.m.s.
%
dB
kV peak
kV rms
Rated primary voltage
Cooling method
- 50 MVA power transformer, or
Rated capacity
- 25 MVA power transformer
Short circuit impedance at 75oC
Tolerance
Zero sequence impedance
Tolerance
Limit of temperature rise of winding, resistance method
Limit of temperature rise of top oil, thermometer method
No-load loss plus positive tolerance
Load loss plus positive tolerance
Exciting current, on high voltage side
Tolerance
Total load of cooling equipment
BIL
Power-frequency test voltage
Voltage regulation at unity power factor
Audible sound level
BIL for secondary side
Power-frequency test voltage for secondary side

Performance data and guarantee of: II Invitation to Bid No.:
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION
Invitation to Bid No.:

Primary 


































-
-
-
kV
A
kV peak
mm
kV r.m.s.
Brown
-
-
-
(Yes/No)

-
Short-circuit withstand current
Neutral point brought out (Yes/No) 
Bushing 
Manufacturer,s name 
Standard 
Number of bushing 
Rated voltage 
Rated current 
BIL 
Creepage distance, between live part to ground 
Power-frequency test voltage, 1 min 
Colour of glazing 
Stud diameter/thread 
Construction of winding 
Construction of core 
On load tap changing will be done at the middle of thetransformer winding (in case of delta winding) 
Brand of oil used for initial filling 

Approved date: 23/09/2559
Specification No.: RTRN-014/2559

Performance data and guarantee of: II
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION
Approved date: 23/09/2559
Specification No.: RTRN-014/2559

(kg) ………………………………………………….. ± ……………………………………………………………. kg
(kg) ………………………………………………….. ± ……………………………………………………………. kg
(kg) ………………………………………………….. ± ……………………………………………………………. kg
Each radiator without oil (kg) ………………………………………………….. ± ……………………………………………………………. kg
(kg) ………………………………………………….. ± ……………………………………………………………. kg
(kg) ………………………………………………….. ± ……………………………………………………………. kg
(kg) ………………………………………………….. ± ……………………………………………………………. kg
Performance data and guarantee of: II
Invitation to Bid No.:
Weight and Tolerance of:
Core
Winding
Part liftable from tank
Oil for each radiator
Total oil filling
Complete transformer
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION
Approved date: 23/09/2559
Specification No.: RTRN-014/2559

: …………………………………………………………………………………………………………………
: …………………………………………………………………………………………………………………
: …………………………………………………………………………………………………………………
: …………………………………………………………………………………………………………………
: …………………………………………………………………………………………………………………
Interrupter (Vacuum technology)
: …………………………………………………………………………………………………………………
Highest voltage for equipment (V)
: …………………………………………………………………………………………………………………
: …………………………………………………………………………………………………………………
Maximum rated step voltage (V)
: …………………………………………………………………………………………………………………
: …………………………………………………………………………………………………………………
Maximum rated through-current (A)
: …………………………………………………………………………………………………………………
: …………………………………………………………………………………………………………………
Number of inherent tapping positions
: …………………………………………………………………………………………………………………
Number of service tapping positions
Quantity of oil used in diverter compartment : …………………………………………………………………………………………………………………
: …………………………………………………………………………………………………………………
: …………………………………………………………………………………………………………………
Performance data and guarantee of: II
Invitation to Bid No.:
2a.2 On-load tap-changer
Manufacturer’s name
Country of origin
Model
Type (resistor or reactor)

Rated step voltage (V)

Rated through-current (A)

Contact life (operations)

BIL (kV peak)
Rated frequency (Hz)
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION
Invitation to Bid No.:
sid
rmers
On secondary
Line

-
50 














-
urrent transfo






C
On primary side 










- 
50 














- 






Characteristics 
Manufacturer's name
Country of origin 
Type of model 
- 

-
kV
kV
Hz
A,V
VA
-
kV peak
kV r.m.s.
kA
kA
-
Class of insulation
Insulation type
Rated primary voltage
Rated secondary voltage
Rated frequency
Ratio
Burden or Capacity of one (1) unit
Accuracy class
Full wave impulse withstand voltage (BIL)
Power-frequency test voltage, 1 minute
Short-time thermal current, 1 second
Dynamic current
Thermal rating

Approved date: 23/09/2559
Specification No.: RTRN-014/2559

Performance data and guarantee of: II
37
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 32 of 60
Invitation to Bid No.:
Performance data and guarantee of: Item………
2a.3 If the detail documents of The Note: Item 1 on Page 33 and 34 of 60 shall be sent to PEA before shipment: (Yes/No)………………………………………………………………………………………………………………….
2a.4 Number of years, from the date of issuance of the notice of acceptance, that the transformers shall be guaranteed:……………………………………………………………………………………………………………………………..
2a.5 Estimation of installation time: ………………….. man-days
2a.6 If the package marking shall be according to those stated in “1d Packing” on Page 19 of 60: (Yes/No)…………………………………………………………………………………………………………………………………
2a.7 If schedule for routine test and type test shall be sent to PEA within one hundred and twenty (120) calendar days after signing the Contract : (Yes/No)……………………………………………………………………
II

38
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 33 of 60
Note: Conditions for documentation and consideration

1. The Contractor shall send the following documents in Thai and/or English, before shipment, for each ordered transformer:
   1.1 Reports of type test and routine test
   1.2 No-load loss and load loss in kW at rated voltage, rated frequency, at 75 degree C, and at:

• No load.
• 25% of maximum rated output
• 50% of maximum rated output
• 75% of maximum rated output
• 100% of maximum rated output
• 110% of maximum rated output
  1.3 Exciting current in amperes at:
• Rated voltage
• 110% of rated voltage
  1.4 Voltage regulation in per cent at:
• Unity power factor
• 0.85 power factor lagging
  1.5 Positive, and zero sequence impedances in per cent based on ONAN rating at rated
  voltage for all windings:
• Resistance
• Reactance
• Total
  1.6 Overall dimensions and weight of all principle parts
  1.7 Identification by name, total weight, and dimensions of the heaviest part that may be
  lifted by crane during assembly or disassembly.
  1.8 Information for reference. The following information for each transformer shall be
  submitted and attached in routine test report for maintenance purpose:
• Coil height for each winding before assembly and after complete assembly
• Torque value on clamping bolts or pressure for each winding before assembly and after
  complete assembly
• Photograph of each coil for each phase and photograph of core and coils assembly.
  The photograph of each coil shall be taken from the final production process before
  placing to the core, top view and front view shall be provided. The photograph of core
  and coils assembly shall be taken just prior to place the completed core and coils
  assembly into the tank, top view, front view, right view, left view and rear view shall
  be provided for complete set of photographs. All photographs shall be 216 mm (8-1/2
  in) by 280 mm (11 in) gloss prints properly labeled relevant to the view taken.
  II

39
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 34 of 60
1.9 Material Tests Report. Test report of the following material and accessories used in each
supply shall be submitted:

• Insulating oil
• Silicon steel
• Copper conductor
• Insulation paper and pressboard
• Radiator
• Transformer supervisory equipments
  1.10 Three (3) sets of instruction book for installation, operation, and maintenance
  1.11 Three (3) sets of control schematic diagrams
  1.12 Three (3) sets of foundation drawings
  Increases in values of Items 1.6 and 1.7 over those mentioned in the Contract shall be + 10%.
  The above documents shall be sent to the following address:
  Transformer Division or Substation Maintenance Division
  Provincial Electricity Authority
  200 Ngam Wong Wan Road, Chatuchak
  Bangkok Metropolis 10900
  Thailand

2. Qualification and guarantee requirement :
   2.1 The offered power transformers shall be manufactured by manufacturers who have no less than five (5) year experience in manufacturing of power transformers with on load tap-changers having rated primary voltage and rated output power no less than the offered power transformers.
   The Bidders have to submit a “5 years Record of Supply” of such transformers with the bid, which are purchased and accepted by public utilities such as PEA, MEA or EGAT and are currently used in full operation.
   The Contractor has to guarantee quality of the above-mentioned on load tap-changing power transformers for three (3) years commencing from the date of the power transformers are accepted by PEA. During the guarantee period, the Contractor will pay an amount equal to the exact purchasing costs for any defective parts of the transformers.
   II

40
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 35 of 60
2.2 The Bidders may offer the power transformers manufactured by manufacturers who have manufactured and sold at least three (3) units of power transformers with on load tap-changers having rated primary voltage and rated output power no less than the offered power transformers and are currently used in full operation.
The manufacturers shall also be accepted by PEA’s, MEA’s or EGAT’s Manufacturer Plant Investigation Committee in order to fulfil the qualification. 1).
The Bidders have to submit a “Record of Supply” of such transformers with the bid.
In this case, the Contractor has to guarantee quality of the above-mentioned on load tap-changing power transformers for five (5) years commencing from the date of the power transformers are accepted by PEA. During the guarantee period, the Contractor will pay an amount equal to the exact purchasing costs for any defective parts of the transformers.
2.3 The Bidders may offer the power transformers manufactured by manufacturers who produce the power transformers under license of a major reputable principal manufacturer who have no less than twenty (20) year experience in manufacturing of power transformers with on load tap changers having rated primary voltage and rated output power no less than the offered power transformers and are currently used in full operation, the licensee shall be received and supported all know-how and references of licensor starting from raw material, transformer specification, design, calculation, manufacturing, quality control and testing procedures of power transformers, the experience and record of supply of power transformers from licensor can be used and submitted with the bid.
The manufacturers shall also be accepted by PEA’s, MEA’s or EGAT’s Manufacturer Plant Investigation Committee in order to fulfil the qualification. 1)
In this case, the Contractor has to guarantee quality of the above-mentioned on load tap-changing power transformers for five (5) years commencing from the date of the power transformers are accepted by PEA. During the guarantee period, the Contractor will pay an amount equal to the exact purchasing costs for any defective parts of the transformers.
2.4 Bidders who offer the power transformers manufactured from the manufacturers without Qualification according to 2.1, 2.2, or 2.3 shall be rejected.

Note: 1) In case the manufacturer requests for an application of the PEA’s Manufacturer Plant Investigation Committee, he shall submit to PEA an official letter requesting for this application at least forty-five
(45) days prior to the receipt of bids.
II

41
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 36 of 60
3. Prices of spare parts and special tools are important factors to be considered.
4. Delivery time is one of the most important factors to be considered.
5. PEA have the right to perform the inspection during the production period, and to witness any test, at the manufacturer’s factory, either by his own staff or by authorized and certified inspectors. The travelling expenses and allowances for inspection and witness the tests are on the account of PEA.
II

42
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 37 of 60
APPENDIX 1
115-22 OR 33 kV POWER TRANSFORMER RATING AND FEATURES

TypeOutdoor, three-phase, two-winding, oil-filled,
conservator type with on-load tap changer
Rated frequency 50 Hz
Rated voltage of winding (Ur)

• HV winding
  115 kV
• LV winding
  23.1 kV or 34.65 kV
  Highest System Voltage
• HV
  123 kV
• LV
  24 kV or 36 kV
  Class ONAN/ONAF 1/ONAF 2 Rated capacity 15/20/25 MVA by ONAN/ONAF 1/ONAF 2 30/40/50 MVA by ONAN/ONAF 1/ONAF 2
  BIL
• HV Delta winding
  550 kV
• HV Star winding
  450 kV
• HV Star neutral
  170 kV
• LV 22 kV winding
  125 kV
• LV 22 kV neutral
  125 kV
• LV 33 kV winding
  170 kV
• LV 33 kV neutral
  170 kV
  Withstand power frequency
• HV Delta winding
  230 kV
• HV Star winding
  185 kV
• HV Star neutral
  70 kV
• LV 22 kV winding
  50 kV
• LV 22 kV neutral
  50 kV
• LV 33 kV winding
  70 kV
• LV 33 kV neutral
  70 kV
  Vector group Dyn1 or YNyn0(d1) Short circuit impedance 7.5% at self cooled rating Load tap changer (rated voltage base) +10% to –10% on HV side 1.25% in each step
  Winding insulation temperature class A

43
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 38 of 60
TypeOutdoor, three-phase, two-winding, oil-filled,
conservator type with on-load tap changer
LV terminal connection Fully enclosed terminal boxes Bushing current transformer Refer to Appendix 4 attached Porcelain insulator color Brown
Winding temperature rise when carrying maximum
continuous rated current (Over 40oC)

• ONAN 55 K
  (measurement by resistance method)
• ONAF 1 and ONAF 2 55 K
  (measurement by resistance method)
• Top oil 50 K
  (measurement by thermometer)
  Average audible sound pressure level at rated voltage
  According to IEC 60076-10 and shall be
  and frequency dB(A)
  not exceed 77 dB
  Power supply system
• AC
  400/230V, 3 phase-4 wire grounded neutral
• DC
  125 V
  Surge arrester on HV side
• Nominal voltage
  115 kV
• Maximum voltage
  123 kV
• Rated frequency
  50 Hz
• Quantity per phase
  1
• Rated voltage
  96 kV
• Nominal discharge current
  10 kA
• Line discharge class
  3
• Discharge residual voltage
  2.85 Ur
• Minimum energy capacity
  4 kJ/kV
• Creepage distance based on maximum voltage
  25 mm/kV for 115-22 kV substation
  31 mm/kV for 115-33 kV substation
• Line terminal
  4 hole NEMA PAD
• Porcelain insulator color
  Brown
• Surge counter with leakage current indicator
  required

44
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 39 of 60
APPENDIX 2
ON LOAD TAP CHANGER SCHEMATIC DRAWING

45
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 40 of 60

46
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 41 of 60
APPENDIX 3
115 – 22 OR 33 KV POWER TRANSFORMERS
TYPICAL INFORMATION AND COMMANDS FOR CSCS
TRANSFORMER SET
I/O POINT COUNTS FOR 115 kV POWER TRANSFORMER
Control Outputs:
Item System Bay Name Point NameDescriptor 0 1
1 115/22 or 33 kV S/S TP__ OLTC Control Set Auto Auto 2 115/22 or 33 kV S/S TP__ OLTC Off Command Off 3 115/22 or 33 kV S/S TP__ OLTC Individual Command Individual 4 115/22 or 33 kV S/S TP__ OLTC Parallel Command Parallel 5 115/22 or 33 kV S/S TP__ OLTC Control Set Manual Manual 6 115/22 or 33 kV S/S TP__ OLTC Raise Command Raise 7 115/22 or 33 kV S/S TP__ OLTC Lower Command Lower 8 115/22 or 33 kV S/S TP__ Fan Control Set Auto Auto 9 115/22 or 33 kV S/S TP__ Fan Control Set Manual Manual 10 115/22 or 33 kV S/S TP__ Fan Group 1 ON Command On 11 115/22 or 33 kV S/S TP__ Fan Group 1 OFF Command Off 12 115/22 or 33 kV S/S TP__ Fan Group 2 ON Command On 13 115/22 or 33 kV S/S TP__ Fan Group 2 OFF Command Off
Analog Points:
Item System Bay Name Point NameDescriptor Unit Scale
1 115/22 or 33 kV S/S TP__ Tap Position 1 1..17 2 115/22 or 33 kV S/S TP__ Winding Temperature A Degree C 0..150 (or equivalent) 3 115/22 or 33 kV S/S TP__ Winding Temperature B Degree C 0..150 (or equivalent) 4 115/22 or 33 kV S/S TP__ Winding Temperature C Degree C 0..150 (or equivalent) 5 115/22 or 33 kV S/S TP__ Oil Temperature Degree C 0..140(or equivalent)

47
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 42 of 60
I/O POINT COUNTS FOR
115 kV POWER TRANSFORMER
Status Points:
Item System Bay Name Point NameDescriptor Point InformationAction
0 1 2 3
1 115/22 or 33 kV S/S TP__ Pressure Relief Normal Trip S T 2 115/22 or 33 kV S/S TP__ VT fail Normal Alarm S - 3 115/22 or 33 kV S/S TP__ Oil level (max.) Normal Alarm S - 4 115/22 or 33 kV S/S TP__ Oil level (min.) Normal Alarm S - 5 115/22 or 33 kV S/S TP__ Oil Temperature Alarm Normal Alarm S - 6 115/22 or 33 kV S/S TP__ Oil Temperature Trip Normal Trip S T 7 115/22 or 33 kV S/S TP__ Buchholz Alarm Normal Alarm S - 8 115/22 or 33 kV S/S TP__ Buchholz Trip Normal Trip S T 9 115/22 or 33 kV S/S TP__ Winding Temperature Alarm Normal Alarm S - 10 115/22 or 33 kV S/S TP__ Winding Temperature Trip Normal Trip S T 11 115/22 or 33 kV S/S TP__ Diverter Switch Oil Level Normal Alarm S - 12 115/22 or 33 kV S/S TP__ Diverter SW Sudden Oil Flow Normal Trip S T 13 115/22 or 33 kV S/S TP__ Tap Change Delay Alarm Normal Alarm S - 14 115/22 or 33 kV S/S TP__ Tap Change in Progress Normal Operate S - 15 115/22 or 33 kV S/S TP__ AC Supply Failure Normal Fail S - 16 115/22 or 33 kV S/S TP__ AC Control Circuit Fail Normal Fail S - 17 115/22 or 33 kV S/S TP__ DC Control Circuit Fail Normal Fail S - 18 115/22 or 33 kV S/S TP__ OLTC Motor Breaker Trip Normal Alarm S - 19 115/22 or 33 kV S/S TP__ OLTC O/C Instantaneous Trip Normal Alarm S - 20 115/22 or 33 kV S/S TP__ OLTC Protective or
Normal Trip S T
Pressure Relay trip
21 115/22 or 33 kV S/S TP__ OLTC Pressure relief trip Normal Trip S T 22 115/22 or 33 kV S/S TP__ OLTC Local/Remote Switch Remote Local S - 23 115/22 or 33 kV S/S TP__ OLTC Control Set Status Undefined Individual Parallel Fault DS - 24 115/22 or 33 kV S/S TP__ OLTC Auto/Manual Status Undefined Manual Auto Fault DS - 25 115/22 or 33 kV S/S TP__ AVR Fail Normal Fail S - 26 115/22 or 33 kV S/S TP__ Fan Motor Breaker Trip Normal Alarm S - 27 115/22 or 33 kV S/S TP__ Fan Thermal Relay Trip Normal Alarm S - 28 115/22 or 33 kV S/S TP__ Parallel Control Failure Normal Alarm S - 29 115/22 or 33 kV S/S TP__ Fan Group 1 Status Undefined Off On Fault DS - 30 115/22 or 33 kV S/S TP__ Fan Group 2 Status Undefined Off On Fault DS - 31 115/22 or 33 kV S/S TP__ Fan Control Set Undefined Manual Auto Fault DS - 32 115/22 or 33 kV S/S TP__ Fan Motor Group#1
Normal Alarm S -
Protection Operated
33 115/22 or 33 kV S/S TP__ Fan Motor Group#2
Normal Alarm S -
Protection Operated
Remark
S : Single point : 1 Bit (0, 1)
DS : Double point : 2 Bit (0, 1, 2, 3)
T : Trip

48
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 43 of 60
APPENDIX 4
115-22 OR 33 kV POWER TRANSFORMERS BUSHING CURRENT TRANSFORMERS
Ratings CT on primary winding
Type Bushing Type
Nominal voltage (kV) 115
Maximum voltage rating (kV) 123
Power frequency (Hz) 50
Number of phases 3
Applicable standard IEC 61869-1 and IEC 61869-2

• Otherwise specified, CT will be designed to accept continuous flow of 120% of rated current without any damage.
• Burdens in the following tables are specified for full range at maximum ratio.
  Type Ratio Core No. Accuracy Burden
  Line bushing
• For 50 MVA Transformer 500-200-100/1 A 1 5P20 20 VA - For 25 MVA Transformer 200-100/1 A 1 5P20 20 VA
  Ratings CT on secondary winding
  Type Bushing Type
  Nominal voltage (kV) 22 or 33
  Maximum voltage rating (kV) 24 or 36
  Power frequency (Hz) 50
  Number of phases 3
  Applicable standard IEC 61869-1 and IEC 61869-2
• Otherwise specified, CT will be designed to accept continuous flow of 120% of rated current without any damage.
• Burdens in the following tables are specified for full range at maximum ratio.

49
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 44 of 60
Type Ratio Core No. Accuracy Burden
Neutral bushing

• For 22 kV 1,800-900/1 A 1 5P20 20 VA 1,800-900/1 A 2 5P20 20 VA
• For 33 kV 1,200-600/1 A 1 5P20 20 VA 1,200-600/1 A 2 5P20 20 VA
  Line bushing for 50 MVA transformer
• For 22 kV 1,800-900/1 A 1 5P20 20 VA 1,800-900/1 A 2 0.5FS5 20 VA
• For 33 kV 1,200-600/1 A 1 5P20 20 VA 1,200-600/1 A 2 0.5FS5 20 VA
  Line bushing for 25 MVA transformer
• For 22 kV 1,000-500/1 A 1 5P20 20 VA 1,000-500/1 A 2 0.5FS5 20 VA
• For 33 kV 600-300/1 A 1 5P20 20 VA 600-300/1 A 2 0.5FS5 20 VA

50
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 45 of 60
APPENDIX 5
SMALL WIRING

1. GENERAL CONDITIONS
   1.1 Scope
   This specification describes the requirements with which the manufacturer shall comply in order to supply 600 V multi-core control cable, copper conductor, flexible metallic sheath.
   1.2 Reference Standards
   All equipment required within the scope of works shall conform as a basic requirement with the following standards:
   IEC 60068 series Environmental testing
   IEC 60947-7-1: 2009 Low voltage switchgear and controlgear – Part 7-1: Ancillary equipment - Terminal blocks for copper conductors
   IEC 60228:2004 Conductor of insulated cables
   TIS 838-2531 Standard for control cables
   PEA will also accept the transformers and accessories tested in accordance with the later edition of the above standards.
   1.3 Principal Requirements
   1.3.1 Service Conditions
   Cable insulating material shall be suitable for installation in wet and dry locations.
   1.3.2 Site and Service Conditions
   The equipment shall be capable of operating at its full ratings under site and service conditions as mentioned below.
   The switchgear room has no air conditioning system.
   Seismic activity: None
   Maximum wind speed: ≈100 km/h
   Maximum recorded rainfall: 250 mm/day
   Number of days with thunderstorm: 100 days/year
   Average rainfall: 20 mm/day
   Mean maximum annual relative humidity: 94%
   Mean minimum annual relative humidity: 79%
   Minimum daily relative humidity: 17%
   Maximum temperature of surfaces exposed to sunbeam: 80°C
   Mean minimum daily temperature: 24°C
   Maximum ambient temperature: 40°C(1)
   Minimum ambient temperature: 11°C
   Maximum ambient temperature in trench for Control cables 65°C
   (1) According to IEC 62271-1 over 40oC will be possible under special requirement.

51
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 46 of 60
1.3.3 Design Requirements
The maximum continuous current-carrying capacity of each individual cable type and cross section used shall be determined, taking into account site conditions. The resulting load reduction factors are subject to the approval by the Authority.
The conductor cross-section of each cable shall be adequate to carry the fault currents determined by the relevant short-circuit protection device when operating under the specified load conditions, without deterioration of the dielectric properties. Calculation including the short-circuit calculations, shall form part of the documents to be supplied by the Contractor.
2. 600 V CONTROL CABLE AND 600 V SWITCHBOARD WIRE
2.1 Control Cable
Construction
The general construction of the control cable shall be suitable for installation in wet and dry locations and shall be furnished with the characteristics described herein. The construction of control cable shall be according to TIS 838 type D (Table 10 of TIS 838).
Spare Conductors. The minimum number of spare conductors in each control cable shall be as follows:
Conductor Number in Cable Minimum Number of Spare Conductors
2 NIL
3 NIL
4 NIL
5 NIL
9 2
12 2
Methods of circuit identification shall be colored compounds with traces according to table 1 (Colors Sequence for Control Cables).
2.2 Switchboard Wire
Construction
The Switchboard wire shall be suitable for installation in dry location especially for wiring used within the control switchboard or other substation equipment control cabinets.
The cable shall be flexible stranded conductor made of annealed round copper wire conformed to IEC 60228 class 5
The insulation consisting of PVC compound shall be applied concentrically on the surface of conductor. The average thickness of the insulation shall be not less than the specified value given in table 4. The minimum thickness shall be not less than 90 percent of the nominal value specified in table 4 minus 0.1 mm.

52
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 47 of 60
Methods of circuit identification shall be colored compounds with traces according to table 2 (Colors for circuit identification).
Table 1: Colors sequence for control cables
Conductor Number Background or Base Color Tracer Color
1 Black -
2 White -
3 Red -
4 Green -
5 Orange -
6 Blue -
7 White Black
8 Red Black
9 Green Black
10 Orange Black
11 Blue Black
12 Black White
Table 2: Colors circuit identification for switchboard wire
Color Circuit identification
Red Power circuit phase A
Yellow Power circuit phase B
Blue Power circuit phase C
Green Neutral wire
Black AC control circuit
Gray DC control circuit
Green/Yellow Grounding wire
Table 3: Stranded conductor for control cables
Conductor Size
No. of Strands Nominal Strand
Approximate Overall
(sq.mm)
Diameter (mm)
Diameter (mm)
1.5 7 0.50 1.50
2.5 7 0.67 2.01
4 7 0.85 2.55
6 7 1.04 3.12

53
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 48 of 60
Table 4: Characteristic of the insulation for switchboard wire
Nominal
Number &
Thickness of
Overall
Maximum
Minimum
AC voltage
Cable weight
sectional
diameter
insulation
diameter
DC
insulation
withstand
(Approx.)
area
of wire
(Approx.)
resistance of
resistance at
test
70 oC
conductor at
20 oC
(sq. mm.)
(No./mm)
(mm)
(mm)
(Ohm/km)
(M-ohm-km)
(kV)
(kg/km)
1.5 36/0.23 0.7 4 13.3 0.010 2.5 19 2.5 60/0.23 0.8 5 7.98 0.009 2.5 30 4.0 56/0.29 0.8 6 4.95 0.007 2.5 44 6.0 84/0.29 0.8 7 3.30 0.006 2.5 65
2.3 Conductors Sizes
2.3.1 Conductor Sizes for Control Cable
Each control cable conductor minimum sizes used for power supply and control circuits shall be as follows:
2.3.1.1 Secondary current transformer circuits 4 sq.mm. (for CTsec1A)
2.3.1.2 Secondary voltage transformer circuit 2.5 sq.mm.
2.3.1.3 Substation equipment D-C or 4 sq.mm.
A-C Control circuits
2.3.1.4 Status and alarm circuit 1.5 sq.mm.
2.3.1.5 Power supply circuit 4 sq.mm.
The voltage drop at the load for 2.3.1.5 shall not be more than 3%.
2.3.2 Conductor sizes for Switchboard and Equipment Control Cabinet Wiring
Wiring used within the switchboards, and other equipment control cabinets shall have minimum sizes as follows:
2.3.2.1 Secondary current transformer circuits 4 sq.mm. (for CTsec1A)
2.3.2.2 Secondary voltage transformer circuits 2.5 sq.mm.
2.3.2.3 Substation equipment D-C or A-C 2.5 sq.mm.
control circuits
2.3.2.4 Status and alarm circuits 1.5 sq.mm.
2.3.2.5 Power supply circuits 4 sq.mm.
Calculation of secondary current circuits for Clauses 2.3.1.1 and 2.3.2.1 shall be submitted to the Authority for approval. The Authority shall review the calculation, if a larger size of control cable and switchboard wire are required for the proper functions of the protection, then the Contractor shall carry out to change the size of the control cable and switchboard wire without extra charge to the Authority.

54
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 49 of 60
2.4 Metallic Shield
Metallic shield shall be made of copper tape for control cables.
As Metal Sheath Cables are installed, non magnetic metallic glands which effective earth the armour, are recommended for all cable entries. All joints in cables should be made in such a way as to prevent entry of vermins as well as to maintain the fire circuit integrity. The manufacturer shall have a tested joint system with test reports indicating compliance. Termination by crimping is recommended.
Metal shields of the control cables shall be grounded at both ends of each cable. Each end of the cable shield shall be welded to an insulated 600V, PVC, copper ground conductor with 6 sq.mm size and this conductor shall then be attached to the ground bus by a terminal lug provided inside of the equipment cabinets, instrument transformer junction boxes, and the switchboards.
Provision for sealing at each end of the cable shall be provided including wrapping over the connection of the shield and the insulated ground conductor by the PVC insulating tape.
2.5 Cable and Wire Markings
The following information shall be printed on the surface of the cable and wires:
2.5.1 Name of manufacturer
2.5.2 Size of cables and wires and number of conductors
2.5.3 Type of insulation
2.5.4 Voltage classification
2.5.5 Date of manufacturer
2.6 Cable Ends
An end cap shall be provided on the cable end to which special attention shall be paid to prevent penetration of moisture during transportation.
2.7 Packing
All cables and wires shall be packed on reels. The reels shall be nonreturnable and shall be included in the prices of the cables and wires offered. The length of the cable and wire to be packed on each reel shall be as indicated below:
Control cables : 500 m + 0.5%
Switchboard wires : 100, 150 or 200 m + 0.5%
The following information shall be displayed:
∙ Name of manufacturer
∙ Size and number of conductors
∙ Type of insulation and voltage classification
∙ Length of cable
∙ Reel number and other suitable indentification for reel and reel size
∙ Date of manufacture
∙ Total weight

55
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 50 of 60
3. TERMINATION AND LABELING
For all terminations of wires and cables the insulation shall be neatly stripped without nicking the strands of the conductors.
Each cable end shall be equipped with compression cable lug. Cable lugs for power cables shall be of adequate size.
Cable shall be firmly fixed on metallic supports.
Brass cable gland shall be used.
Cable glands or clamps shall be fitted in all cases to prevent stresses on conductors or terminals. It is important that the sealing compound and sleeving used in terminations is selected to suit the service conditions under which the cable is to operate.
No terminations will be accepted, if the insulation readings, 24 hours after making off, is less than 100 megohm using a standard 500 V or 1,000 V “Megger” (cables only).
Some slack cable in a loop or other suitable form is to be provided in a convenient place in the runs, where required.
Designation of each end of cable conductor or switchboard wire shall be marked with destination terminal name.(Near and far end terminal name)
Each terminal shall carry a letter or number marking. Terminals shall be numbered on the terminal block in chronological order, from left to right and from bottom to top.
Dividers shall be provided to separate incomings. In addition, provision of a side marking shall allow identification of the cable arriving from the outside. Terminal covers with dividers shall be fitted onto power terminal blocks.
The wiring shall be arranged so as to avoid masking the distinctive markings of functional elements.
Wiring drawings for control and relay panels shall show wire and cable terminations for external wiring.
The ends of each cable core and all secondary panel wiring shall be fitted with white ferrules marked by printed black numbers, with the identification being the same as for the relevant terminals. Both ends of each cable shall be marked with terminal destination, including cubicle name, equipment name and pin number.
In case different terminal boards are arranged close to each other, the numbers on the ferrules shall contain the terminal board denomination and the terminal number. The ferrules shall be fitted in such a way, that they cannot become detached when the wire is removed from the terminal. All internal wiring shall enter the terminal block from one side only.
The moisture and oil-resisting insulation material shall have a gloss finish.
All wiring used within the equipment control cabinets switchboards, and interposing relay cabinets shall meet the requirements of this Specification.

56
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 51 of 60
4. INSTALLATION
4.1 General requirements
The Contractor shall perform all relevant design and dimensioning of the complete cable systems and prepare the cable installation drawings with cable routing, connection diagrams and cable lists, details, etc.
All secondary wiring shall be arranged and protected to prevent damage it by arcing or by mechanical effects.
Power supplies for all control circuits of switchboard mounted devices, all control cabinet mounted devices, VT secondary circuits, and any other individual control circuits shall each be protected and provided with a miniature circuit breaker connected to isolate the devices from power supplies in the tripped or open position. The miniature circuit breakers shall be located within the switchboards or cabinets. Engraves nameplates shall be installed beside each set of the miniature circuit breaker for identification.
Each miniature circuit breaker shall be equipped with two electrically separated normally closed contacts: one for initiating the annunciator on the switchboard panel and the other shall be wired to the CSCS for alarm.
Wiring shall be neatly run, bundled or in rigid PVC wire-ways filled to not more than 70%.
Different functions of service, such as VT and CT circuits, tripping and annunciation shall not be routed in the same cable.
Control cables and high voltage power cables shall not use the same route.
Low voltage power cables and control cables shall be adequately spaced.
The installation of wiring shall take into account stresses due to vibration and the proximity of elements dissipating heat.
The Contractor shall ensure that all cabinets of the same type are wired in an identical manner.
All necessary precautions shall be taken to minimize inductive and capacitive coupling between different types of circuit.
Special precaution shall be taken to ensure, that no magnetic circuit is formed around single-core cables laid in single or trefoil formation, or around any cable liable to carry unbalanced currents.
The wiring shall be laid in ridged plastic ducts with slotted lateral openings. The conductors placed in the ducts shall have sufficient extra length. The fill factor for ducts shall not exceed 70%. The plastic material shall be sturdy and shall allow the ducts to withstand the impact resistance tests on apparatus with a reinforced enclosure. Burning of the plastic material through exposure to flame shall not spread beyond the combustion zone once the flame has been removed.
Splices or tee connections shall not be permitted in control wiring or instrument leads. Terminal blocks shall be used for all terminations.

57
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 52 of 60
The cut end of cables shall be treated to prevent seepage of water into the cable. When unreeling cable from the cable drums, special care shall be taken to prevent damage to the cables. When moving the cover of the drum, care shall be taken to prevent damage to the cable sheath.
The Contractor shall provide all necessary materials for installation of the cables, such as grounding lead wires, compression type terminals, metal fitting, bolts and nuts including cable identification and felt packing to be inserted between cables and cleats.
Cables installed on cable racks, shall be firmly fixed to the cable rack at suitable intervals by plastic cable ties or equivalent.
All cables shall be provided with cable support.
During installation, care shall be taken not to damage the outer sheath of all wires and cable. Cables damaged during installation shall be repaired or replaced to PEA satisfaction at no additional charge.
4.2 Connections
In low voltage equipment, there are many connections, and faults caused by them play a major part in declining reliability of equipment. For each wire no intermediate connection is allowed between terminal blocks or equipments. It shall therefore be necessary to guarantee reliability of components used and to take care in their installation.
∙ Crimping
This type of connection shall be made with specially designed equipment for the type of
crimping required.
Crimping of two conductors in the same cable lug or in the same terminal end shall be
prohibited.
∙ Connection by Coiled Wire (Wire Wrapping).
This connection technique requires use of a special tool and shall be implemented following
good trade practice (choice of post, device, etc.)
∙ Screw-Type Connection
The design of the various elements shall guarantee against any accidental unscrewing.
The tightening of conductors shall guarantee a low contact resistance and secure attachment of
the conductor, without damaging it.
∙ Clip Connection
The quality of this type of connection depends largely on the quality of the components used;
the Contractor shall indicate their characteristics.
∙ Connection by Connectors
The connectors installed in humid premises or outdoors shall have the following
characteristics:

58
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 53 of 60
- quality and protection of electrical contacts for low currents (gold on nickel),

• watertight against dripping from whatever direction,
• withstand to 100% environment (relative humidity),
• corrosion resistant material (“Marine” bronze).
  The connection of connectors shall be carried out by qualified personnel.
  The guarantee of effective watertightness of the cable-connector assembly shall require the
  installation on each cable of a heat-shrinking cap, with epoxy resin injection in the hollow
  parts.
  Each end of conductor of control cable and switchboard wire shall be provided with ring
  tongue terminal lug to avoid CT open-circuited due to a loose screw.
  4.3 Terminal-Terminal Blocks
  All electrical connections from equipment to the outside shall be via terminal blocks. These terminal blocks shall be positioned vertically on both sides of the frame and in the lower part of cubicles or accessories.
  The terminals shall be installed on metal “support plates” which serve as both the mount and the securing device of the assembly.
  Each bank of terminals shall be blocked off at the each end by a fixed stop.
  Terminals with clamping screws in direct contact with the conductor are not acceptable.
  Terminal for CT circuit shall be of the short-link type.
  Terminals blocks shall be grouped by category:
  X1 - For annuciator circuit
  X2 - For indicator circuit
  X3 - For control and auxiliary relay circuit
  X4 - For VT circuit
  X5 - For DC auxiliary supply
  X6 - For CSCS circuit
  X7 - For AC auxiliary supply
  X8 - For Capacitor bank
  X9 - For CT circuit
  For each category, terminal blocks shall be provided with 20% spare terminals.
  Insulating barriers shall be provided using separators to avoid any short-circuits. Terminals shall be sized according to the conductors to be connected (8 mm pitch terminals with 4 mm test cells or 6 mm pitch terminals with 2 mm test cells).
  Each terminal shall carry a printed letter or number marking. Terminals shall be numbered on the terminal block in chronological order, from left to right and from bottom to top.

59
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 54 of 60
Dividers shall be provided to separate incomings. In addition, provision of a side marking shall allow identification of the cable arriving from the outside. Terminal covers with dividers shall be fitted onto power terminal blocks.
4.4 Test Boxes
4.4.1 Verification of Measuring and Protection Devices.
Test block boxes shall be used to verify the essential circuits of protection and metering devices, since they facilitate inspection operations without affecting the safety of the assembly. They shall allow simultaneous measurement of currents and voltages feeding these protection systems and shall cancel all functions, except alarms and indications, during tests.
Protection systems mounted in cubicles shall always be fitted with these boxes to facilitate their testing using suitable testing sets.
These boxes shall always admit a current of 30 A, withstanding over-currents from major faults - over-currents which are fully transmitted by current reducers.
Depending on the complexity of the diagrams or the verifications to be performed, the terminal boxes may correspond either to each set of instrument transformers, or to a measurement unit or specific protection unit.
The various circuits may be tested in operation.
4.4.2 Voltage and Current Test
Boxes used for testing shall be closed by a cover, allowing continuity of the circuits.
These boxes shall not break the circuits when the cover is removed. For CT circuit, short circuit facilities shall be provided.
These boxes shall be flush mounted.
The maximum acceptable intensity shall always be 30 A. The dielectric strength testing voltage shall be 2,000 V, 50Hz.
The various elements comprising these boxes shall be protected from environmental factors, in compliance with IEC 60068.
Sockets shall include an orientation pin to avoid any connection errors.
The various position and combination of these pins shall be proposed by the Contractor.
By-pass of the “voltage” circuits on the terminal block shall be possible.
Screw-type connection shall be used.
“Current” circuits shall always be connected using round centrally drilled cable lugs.
4.4.3 Associated Testing Equipment.
The Contractor providing the elements fitted with test boxes shall also provide equipment for testing the circuits.
Connection sockets with leads shall be provided.

60
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 55 of 60
4.4.4 Installation.
All the test boxes installed shall be of the same type.
5. CABLE LAYING
The Contractor shall select the most suitable cable routes and raceways, ensuring a minimum of interference with other installations.
Routing shall be as short as possible, and shall pass through reserved areas free of any components, screws and bolts; in the proximity of removable or adjustable elements, wires shall be effectively protected.
As appropriate for the various locations the cables shall be installed in cable ducts, raceways, conduit or tray systems, cable trenches, etc., or laid directly in the ground.
Cables running inside buildings or concrete trenches shall be laid on trays. The trays shall be of adequate strength and size to carry the specified number of cables, provide 25% spare capacity. The design of such trays shall include a safety factor to avoid permanent distortion, when supporting erection staff during cable installation. The trays shall be of suitable aluminium alloys or hot-dip galvanized steel standard materials.
Cable trays shall normally be of the ladder-type consisting of bars with rungs, evenly spaced (maximum 300 mm) according to requirements. Perforated, covered metal trays shall be used in highly polluted or otherwise endangered surroundings. All trays shall be rigidly fixed on supporting steel structures, masonry or galvanized racks. Cable trays arranged one above the other shall be at least 200 mm apart in case of power cables and 150 mm in case of control cables.
Earthing cable of the same size the one used for grounding grid shall be laid along cable tray and fixed as shown on corresponding drawing.
Cables laid on trays or racks shall be properly fixed or clamped. Supports and racks shall be arranged to facilitate removal or replacement of cables.
Cables branched from general raceways and directed to the relevant equipment shall be suitably protected, where required, over their entire lengths by e.g. galvanized steel conduits sealed at their ends against ingress of water. Conduits shall be fixed on steel structures, brickwork or be embedded in concrete floors or walls according to field requirements.
Conduits embedded in concrete or block-work shall be of a suitably rigid PVC-type. Cables laid outdoors, across roads in concrete or foundations shall run in hard PVC plastic pipes buried in ground at a depth of not less than 600 mm or embedded in concrete foundations at suitable depth. The cross-sectional area of such ducts shall be utilized to 50% only. Pipe ducts shall terminate in concrete draw pits before entering buildings. Draw-pits shall be provided where required to facilitate cable installation.

61
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 56 of 60
Cables on brick walls or similar civil structures can be installed in conduits (galvanized steel conduits within the reach of persons or erection/maintenance devices, PVC conduits in other areas) or in pre-fabricated installation channels made of galvanized sheet metal or plastic.
Unarmored cables shall be properly protected against mechanical damage, where leaving ducts or covered trenches and the like.
Fire-partitions shall be provided where cables are passing through different fire zones or where entering cubicles and panels.
Pulling, fixing and terminating of cables shall be strictly in accordance with the manufacturer’s instructions, using the recommended tools and appliances.

62
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 57 of 60
APPENDIX 6
Bill of Material (BOM)
OLTC Power Transformer Bill of Material (BOM)
OLTC Power Transformer Bill of Material (BOM)
Item Description Unit(s) Type/Model Manufacturer/Country Quantities 1 On load tap changer (OLTC) set(s) 1 2 OLTC motor drive unit set(s) 1 3 Primary bushing with terminal NEMA pad set(s) 3(4) 4 Secondary bushing with terminal NEMA pad set(s) 4 5 Oil conservator tank for main tank set(s) 1 6 Oil conservator tank for OLTC set(s) 1 7 Air breather for main tank set(s) 1 8 Air breather for OLTC set(s) 1 9 Buchholz relay for main tank set(s) 1 10 Oil surge protective relay for main tank (if any) set(s) 1 11 OLTC protective relay or pressure relay set(s) 1 12 Transformer pressure relief device set(s) 1 13 OLTC pressure relief device set(s) 1 14 Transformer oil temperature monitoring device
set(s) 1
(Conventional Dial type)
15 Transformer winding temperature monitoring
set(s) 3
device(Conventional Dial type)
16 Transformer oil level monitoring device (Conventional Dial
set(s) 1
type)
17 OLTC oil level monitoring device (Conventional Dial type) set(s) 1 18 Pressure-Vacuum gauge set(s) 1 19 Upper filter valve, globe type or stainless steel ball type lot(s) 1 20 Oil drain and filter valve, globe type or stainless steel ball
lot(s) 1
type
21 Oil sampling valves lot(s) 1 22 Sludge drain valve lot(s) 1 23 Lifting lug lot(s) 1 24 Jacking bosses(pads) lot(s) 1 25 Handhole and/or manhole on cover lot(s) 1 26 Cover lifting eyes lot(s) 1 27 Pulling eyes lot(s) 1 28 Nameplate with connecting diagram set(s) 1 29 ladder set(s) 1 30 Plate of 400 x 200 mm, provided for painting PEA serial No. set(s) 1 31 115 kV Lightning arrester set(s) 3 32 22(33) kV Lightning arrester (if any) set(s) 3 33 Insulating oil lot(s) 1 34 Cooling fan lot(s) 1 35 Primary bushing current transformer set(s) 3(4)

63
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 58 of 60
OLTC Power Transformer Bill of Material (BOM)
Item Description Unit(s) Type/Model Manufacturer/Country Quantities 36 Secondary bushing current transformer set(s) 4 37 Voltage transformer set(s) 1 38 Earthing terminal lot(s) 1 39 Other accessories lot(s) 1
Power Transformer RCC Panel Bill of Material (BOM)
Power Transformer RCC Panel Bill Of Material (BOM)
Item Description Unit(s) Type/Model Manufacturer/Country Quantities 1 Cubicle set(s) 1 2 Earthing BUS lot(s) 1 3 Voltage regulator relay set(s) 1 4 1 Phase Ammeter set(s) 3 5 1 Phase Voltmeter set(s) 1 6 Tap position indicator set(s) 1 7 3 phase open phase relay set(s) 1 8 Auto/Manual selector switch for OLTC set(s) 1 9 Auto/Manual selector switch for cooling system set(s) 1 10 On/off switch for cooling system set(s) 1 11 Tap raise/lower control switch set(s) 1 12 Individual/Parallel selector switch set(s) 1 13 Master/Follower selector switch (if any) set(s) 1 14 SCADA/Local control selector switch set(s) 1 15 Resistance transducer set(s) 1 16 DC under voltage Alarm Relay lot(s) 1 17 High speed auxiliary trip relay set(s) 1 18 Auxiliary relays lot(s) 1 19 Timer relays lot(s) 1 20 Latching relays lot(s) 1 21 Indicating Lamp(LED type) lot(s) 1 22 1 Phase Current Transducer (if any) set(s) 3 23 1 Phase Voltage Transducer (if any) set(s) 1 24 CT test terminal set(s) 1 25 VT test terminal set(s) 1 26 MCB with Aux. Contacts lot(s) 1 27 Fuse with Fuse Holder and Spare(if any) lot(s) 1 28 Wire Way or Control cable box lot(s) 1 29 Push button lot(s) 1 30 Anunciator with Accessory set(s) 1 31 Control Cable Support lot(s) 1 32 Horn set(s) 1 33 Horn relay set(s) 1 34 Heater set(s) 1 35 Hygrostat set(s) 1

64
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 59 of 60
Power Transformer RCC Panel Bill Of Material (BOM)
Item Description Unit(s) Type/Model Manufacturer/Country Quantities 36 Heater Control Switch Off-Auto-Manual set(s) 1 37 Door Switch of Limit Switch set(s) 1 38 Service Lighting (Fluoresent Lamp) set(s) 1 39 Terminal for CT Circuit (Short sand slide link type) lot(s) 1 40 Terminal for VT circuit lot(s) 1 41 Terminal for Control lot(s) 1 42 Terminal for CSCS lot(s) 1 43 Terminal Lug lot(s) 1 44 CT Circuit Cable lot(s) 1 45 VT Circuit Cable lot(s) 1 46 CSCS Circuit Cable lot(s) 1 47 Control cable lot(s) 1 48 Wire Marking lot(s) 1 49 Other Accessories lot(s) 1
Power Transformer LCC Panel Bill Of Material (BOM)
Power Transformer LCC Panel Bill Of Material (BOM)
Item Description Unit(s) Type/Model Manufacturer/Country Quantities 1 Cubicle set(s) 1 2 Earthing BUS lot(s) 1 3 3 phase over current relay set(s) 1 4 1 Phase Ammeter set(s) 3 5 1 Phase Voltmeter set(s) 1 6 AC under voltage relay set(s) 1 7 On/off switch for cooling system set(s) 1 8 Auto/Manual selector switch for cooling system set(s) 1 9 Cooling system group selector switch set(s) 1 10 Remote/Local selector switch for OLTC set(s) 1 11 Remote/Local selector switch for cooling system set(s) 1 12 DC Under Voltage Alarm Relay (27X) lot(s) 1 13 Auxiliary relays lot(s) 1 14 Latching relays lot(s) 1 15 Indicating Lamp(LED type) lot(s) 1 16 1 Phase Current Transducer (if any) set(s) 3 17 1 Phase Voltage Transducer (if any) set(s) 1 18 MCB with Aux. Contacts lot(s) 1 19 Fuse with Fuse Holder and Spare (if any) lot(s) 1 20 Wire Way or Control cable box lot(s) 1 21 Push button lot(s) 1 22 Anunciator with Accessory (if any) set(s) 1 23 Control Cable Support lot(s) 1 24 Horn set(s) 1 25 Heater set(s) 1 26 Hygrostat set(s) 1

65
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATION
Specification No. RTRN-014/2559
Approved date: 23/09/2559
Rev. No. : 3
Form No. 02-2
Page 60 of 60
Power Transformer LCC Panel Bill Of Material (BOM)
Item Description Unit(s) Type/Model Manufacturer/Country Quantities 27 Heater Control Switch Off-Auto-Manual set(s) 1 28 Door Switch of Limit Switch set(s) 1 29 Service Lighting (Fluoresent Lamp) set(s) 1 30 Terminal for CT Circuit (Short sand slide link type) lot(s) 1 31 Terminal for VT circuit lot(s) 1 32 Terminal for Control lot(s) 1 33 Terminal for CSCS (if any) lot(s) 1 34 Terminal Lug lot(s) 1 35 CT Circuit Cable lot(s) 1 36 VT Circuit Cable lot(s) 1 37 CSCS Circuit Cable (if any) lot(s) 1 38 Control cable lot(s) 1 39 Wire Marking lot(s) 1 40 Other Accessories lot(s) 1

66
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
Specification No. RTRN-014/2559: ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATIONS
Page 1 of 11
C3 Schedule of detailed requirement
Invitation to Bid No.:
Item
PEA
Material
No.
Quantity
Description
1
1050020002 II
lot(s)
1.1 ………unit(s) On-load tap-changing power transformer, three-phase, 50 Hz, with:
Rated primary voltage : 115 kV
Rated secondary voltage : 23.1GrdY/13.3 kV (Wye-ground) Rated MVA output power,
Cooling method : 30/40/50, ONAN/ONAF1/ONAF2 OLTC type : vacuum interrupter type On-load tapping voltage
on primary side : +10% to -10% of nominal primary voltage 1.25% in each step
Vector group : Dyn 1
The low-voltage side shall be equipped with airfilled cable box opposite to the high-voltage bushing. The cable entrances shall be designed in such a manner that cables enter underneath the cable box. The low-voltage take off shall be two (2) circuits per phase designed suitable for cable termination kit as stated in (5) below.
Each transformer shall be completed with:
(1) Current transformers
(2) Voltage transformer
(3) 3 sets Lightning arrester (surge arrester), for outdoor installation, manufactured and tested in accordance with the latest IEC 60099-4 line discharge class 3 or equivalent, fitted with pressure-relief device, with:
Rated voltage (Ur) : 96 kV
Max. residual voltage at 10 kA
discharge current : not more than 2.85 Ur Pressure-relief class : A
Each complete with:

• line terminal connector, solderless clamp type, for aluminium conductor 17.6-20.2 mm in diameter (size 185-240 mm2),
• ground terminal connector, solderless clamp type, for copper conductor 12.6 mm in diameter (size 95 mm2),
• insulating base, and
• mounting hardware

67
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
Specification No. RTRN-014/2559: ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATIONS
Page 2 of 11
C3 Schedule of detailed requirement
Invitation to Bid No.:
Item
PEA
Material
No.
Quantity
Description
2
-
1050020003 -
II
lot(s)
(4) 3 sets Discharge counter for recording the number of lightning arrester discharger on the above lightning arrester, for outdoor installation.
(5) 6 sets Cable termination kit, prefabricated type or heat shrinkable tubing type, for system voltage of 22 kV, for connecting the underground power cable size 500 mm2 (conductor diameter of 26.7 mm and overall cable diameter of 52 mm) to the transformer. Complete with terminal lug and mounting hardware.
The lug shall be drilled four (4) holes in accordance with NEMA Standards (14 mm holes on 44.5 mm centers).
(6) Necessary accessories according to manufacturer’s design for operation.
1.2 1 lot Supervisor(s) for installation the above transformers until ready for operation at PEA’s sub-transmission substation.
2.1 ………unit(s) Ditto as 1.1, but the vector group shall be YNyn0(d1)
2.2 1 lot Supervisor(s) for installation the above transformers until ready for operation at PEA’s sub-transmission substation.

68
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
Specification No. RTRN-014/2559: ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATIONS
Page 3 of 11
C3 Schedule of detailed requirement
Invitation to Bid No.:
Item
PEA
Material
No.
Quantity
Description
3
1050020004 II
lot(s)
3.1 ………unit(s) On-load tap-changing power transformer, three-phase, 50 Hz, with:
Rated primary voltage : 115 kV
Rated secondary voltage : 23.1GrdY/13.3 kV (Wye-ground) Rated MVA output power,
Cooling method : 15/20/25, ONAN/ONAF1/ONAF2 OLTC type : vacuum interrupter type On-load tapping voltage
on primary side : +10% to -10% of nominal primary voltage 1.25% in each step
Vector group : Dyn 1
The low-voltage side shall be equipped with airfilled cable box opposite to the high-voltage bushing. The cable entrances shall be designed in such a manner that cables enter underneath the cable box. The low-voltage take off shall be two (2) circuits per phase designed suitable for cable termination kit as stated in (5) below.
Each transformer shall be completed with:
(1) Current transformers
(2) Voltage transformer
(3) 3 sets Lightning arrester (surge arrester), for outdoor installation, manufactured and tested in accordance with the latest IEC
60099-4 line discharge class 3 or equivalent, fitted with
pressure-relief device, with:
Rated voltage (Ur) : 96 kV
Max. residual voltage at 10 kA
discharge current : not more than 2.85 Ur Pressure-relief class : A
Each complete with:

• line terminal connector, solderless clamp type, for aluminium conductor 17.6-20.2 mm in diameter (size 185-240 mm2),
• ground terminal connector, solderless clamp type, for copper conductor 12.6 mm in diameter (size 95 mm2),
• insulating base, and
• mounting hardware.

69
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
Specification No. RTRN-014/2559: ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATIONS
Page 4 of 11
C3 Schedule of detailed requirement
Invitation to Bid No.:
Item
PEA
Material
No.
Quantity
Description
4
-
1050020005 -
II
lot(s)
(4) 3 sets Discharge counter for recording the number of lightning arrester discharger on the above lightning arrester, for outdoor installation.
(5) 6 sets Cable termination kit, prefabricated type or heat shrinkable tubing type, for system voltage of 22 kV, for connecting the underground power cable size 500 mm2 (conductor diameter of 26.7 mm and overall cable diameter of 52 mm) to the transformer. Complete with terminal lug and mounting hardware.
The lug shall be drilled four (4) holes in accordance with NEMA Standards (14 mm holes on 44.5 mm centers).
(6) Necessary accessories according to manufacturer’s design for operation.

3.2 1 lot Supervisor(s) for installation the above transformers until ready for operation at PEA’s sub-transmission substation.
4.1 ………unit(s) Ditto as 3.1, but the vector group shall be YNyn0(d1).
4.2 1 lot Supervisor(s) for installation the above transformers until ready for operation at PEA’s sub-transmission substation.

70
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
Specification No. RTRN-014/2559: ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATIONS
Page 5 of 11
C3 Schedule of detailed requirement
Invitation to Bid No.:
Item
PEA
Material
No.
Quantity
Description
5
1050020100 II
lot(s)
5.1 ………unit(s) On-load tap-changing power transformer, three-phase, 50 Hz, with:
Rated primary voltage : 115 kV
Rated secondary voltage : 34.65GrdY/20 kV (Wye-ground) Rated MVA output power,
Cooling method : 30/40/50, ONAN/ONAF1/ONAF2 OLTC type : Vacuum interrupter type On-load tapping voltage
on primary side : +10% to -10% of nominal primary voltage 1.25% in each step
Vector group : YNyn0 (d1)
The low-voltage side shall be equipped with airfilled cable box opposite to the high-voltage bushings. The cable entrances shall be designed in such a manner that cables enter underneath the cable box. The low-voltage take off shall be two (2) circuits per phase designed suitable for cable termination kit as stated in (5) below.
Each transformer shall be completed with:
(1) Current transformers
(2) Voltage transformer
(3) 3 sets Lightning arrester (surge arrester), for outdoor installation, manufactured and tested in accordance with the latest IEC 60099-4 line discharge class 3 or equivalent, fitted with pressure-relief device, with :
Rated voltage (Ur) : 96 kV
Max. residual voltage at 10 kA
discharge current : not more than 2.85 Ur Pressure-relief class : A
Each complete with:

• line terminal connector, solderless clamp type, for aluminium conductor 17.6-20.2 mm in diameter (size 185-240 mm2),
• ground terminal connector, solderless clamp type,for copper conductor 12.6 mm in diameter (size 95 mm2),
• insulating base, and
• mounting hardware

71
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
Specification No. RTRN-014/2559: ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATIONS
Page 6 of 11
C3 Schedule of detailed requirement
Invitation to Bid No.:
Item
PEA
Material
No.
Quantity
Description

-  

II

 (4) 3 sets Discharge counter for recording the number of lightning  arrester discharger on the above lightning arrester, for outdoor  installation.  

(5) 6 sets Cable termination kit, prefabricated type or heat shrinkable tubing type, for system voltage of 22 kV, for connecting the underground power cable size 500 mm2 (conductor diameter of 26.7 mm and overall cable diameter of 52 mm) to the transformer. Complete with terminal lug and mounting hardware.
The lug shall be drilled four (4) holes in accordance with NEMA Standards (14 mm holes on 44.5 mm centers) .
(6) Necessary accessories according to manufacturer’s design for operation.
5.2 1 lot Supervisor(s) for installation the above transformers until ready for operation at PEA’s sub-transmission substation.

72
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
Specification No. RTRN-014/2559: ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATIONS
Page 7 of 11
C3 Schedule of detailed requirement
Invitation to Bid No.:
Item
PEA
Material
No.
Quantity
Description
6
1050020101 II
lot(s)
6.1 ………unit(s) On-load tap-changing power transformer, three-phase, 50 Hz, with:
Rated primary voltage : 115 kV
Rated secondary voltage : 34.65GrdY/20 kV (Wye-ground) Rated MVA output power,
Cooling method : 15/20/25, ONAN/ONAF1/ONAF2 OLTC type : vacuum interrupter type On-load tapping voltage
on primary side : +10% to -10% of nominal primary voltage 1.25% in each step Vector group : YNyn0 (d1)
The low-voltage side shall be equipped with airfilled cable box opposite to the high-voltage bushings. The cable entrances shall be designed in such a manner that cables enter underneath the cable box. The low-voltage take off shall be two (2) circuits per phase designed suitable for cable termination kit as stated in (5) below.
Each transformer shall be completed with:
(1) Current transformers
(2) Voltage transformer
(3) 3 sets Lightning arrester (surge arrester), for outdoor installation, manufactured and tested in accordance with the latest IEC 60099-4 line discharge class 3 or equivalent, fitted with pressure-relief device, with:
Rated voltage (Ur) : 96 kV
Max. residual voltage at 10 kA
discharge current : not more than 2.85 Ur Pressure-relief class : A
Each complete with:

• line terminal connector, solderless clamp type, for aluminium conductor 17.6-20.2 mm in diameter (size 185-240 mm2),
• ground terminal connector, solderless clamp type,for copper conductor 12.6 mm in diameter (size 95 mm2),
• insulating base, and
• mounting hardware

73
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
Specification No. RTRN-014/2559: ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATIONS
Page 8 of 11
C3 Schedule of detailed requirement
Invitation to Bid No.:
Item
PEA
Material
No.
Quantity
Description

-  

II

(4) 3 sets Discharge counter for recording the number of lightning  arrester discharger on the above lightning arrester, for  outdoor installation.  

(5) 6 sets Cable termination kit, prefabricated type or heat shrinkable tubing type, for system voltage of 22 kV, for connecting the underground power cable size 500 mm2 (conductor diameter of 26.7 mm and overall cable diameter of 52 mm) to the transformer. Complete with terminal lug and mounting hardware.
The lug shall be drilled four (4) holes in accordance with NEMA Standards (14 mm holes on 44.5 mm centers).
(6) Necessary accessories according to manufacturer’s design for operation.
6.2 1 lot Supervisor(s) for installation the above transformers until ready for operation at PEA’s sub-transmission substation.

74
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
Specification No. RTRN-014/2559: ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATIONS
Page 9 of 11
C3 Schedule of detailed requirement
Invitation to Bid No.:
Item
PEA
Material
No.
Quantity
Description
7
-
II
lot(s)
Spare parts for the transformers in 1.1
7.1 1 set Spare gasket for HV bushing
7.2 1 set Spare gasket for LV and neutral bushing
7.3 1 set Spare oil level sensor for main tank
7.4 1 set Spare oil level sensor for OLTC
7.5 1 set Spare oil temperature sensor
7.6 1 set Spare winding temperature sensor
7.7 1 set Spare annunciator unit
7.8 1 set Spare buchholz relay
7.9 1 set Spare protective relay for OLTC
7.10 1 set Spare instantaneous overcurrent relay
7.11 1 set Spare current transformer for primary side
7.12 1 set Spare current transformer for secondary side
7.13 1 set Spare current transformer for neutral bushing
7.14 1 set Spare voltage transformer
7.15 2 sets Spare primary bushing
7.16 2 sets Spare secondary bushing
7.17 3 sets Spare surge arrester 96 kV
7.18 1 set Spare relays and contactors
7.19 1 set Spare pressure relief device
7.20 1 set Spare cooling assembly
7.21 1 set Spare protective relay for cooling fan motor
7.22 1 set Spare oil pump
7.23 1 set Special tools for OLTC maintenance
7.24 1 set Spare OLTC complete set
7.25 1 set Spare voltage regulator for OLTC
7.26 2 sets Spare voltmeter
7.27 2 sets Spare ammeter
7.28 1 set Spare open-phase relay
7.29 2 sets Spare analog meter for oil-temperature
7.30 2 sets Spare analog meter for winding-temperature
7.31 1 set Spare dehydrating breather for main tank conservator 7.32 1 set Spare dehydrating breather for OLTC conservator

75
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
Specification No. RTRN-014/2559: ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATIONS
Page 10 of 11
C3 Schedule of detailed requirement
Invitation to Bid No.:
Item
PEA
Material
No.
Quantity
Description
8
9
10
11
12
13
14
15
16
17
18
-

II
lot(s)
lot(s)
lot(s)
lot(s)
lot(s)
lot(s)
lot(s)
lot(s)
lot(s)
lot(s)
lot(s)
Spare parts for the transformers in 2.1, ditto as Item 7
Spare parts for the transformers in 3.1, ditto as Item 7
Spare parts for the transformers in 4.1, ditto as Item 7
Spare parts for the transformers in 5.1, ditto as Item 7
Spare parts for the transformers in 6.1, ditto as Item 7
Special tools, for the transformer in 1.1
Special tools, for the transformer in 2.1
Special tools, for the transformer in 3.1
Special tools, for the transformer in 4.1
Special tools, for the transformer in 5.1
Special tools, for the transformer in 6.1

76
PROVINCIAL ELECTRICITY AUTHORITY

TECHNICAL SPECIFICATION DIVISION
Specification No. RTRN-014/2559: ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION SUBSTATIONS
Page 11 of 11
C3 Schedule of detailed requirement
Invitation to Bid No.:
Item
PEA
Material
No.
Quantity
Description

II 


Note: 

1. Bidders have to quote supervisor(s) costs (wage) for the erection, test and commissioning transformers until ready for operation. PEA shall provide and arrange civil work, workmen, and tools for erection.
2. Remote control cabinet shall be installed in PEA’s control room, approximately 100 m from the transformer. PEA shall supply the control cable.
3. Catalogues, characteristics, dimensions and details of lightning arresters, discharge counter, and oil purifier shall be submitted with the bid. 4. Bidders have to quote optional accessories, spare parts and special tools (if any) with a list of quantities and their itemized prices; PEA reserves the right to purchase some or all of items, to adjust their quantities, or to cancel them. 5. Monitoring system for power transformer shall be of conventional type completing with all interfacing required by CSCS system (4-20 mA for interfacing to CSCS system).
4. The Contractor shall supply control and circuit diagram, for approval by Substation Construction Division within fifteen (15) calendar days after signing the contract.

ManufacturCountry of Trade-mark
Quantitu1 lot
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
Specification No. RTRN-014/2559: ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION C4 Price schedule
Complete with current and voltage transformers, lightning arrester, discharge counter, cable termination kits, and other accessories.
: +10% to -10% of nominal primary
: 23.1GrdY/13.3 kV (Wye-ground)
1.1 On-load tap-changing power transformer, three-phase, 50 Hz, with:
: 30/40/50, ONAN/ONAF1/ONAF2
voltage 1.25% in each step
: vacuum interrupter type
1.2 Supervisor(s) for installation the above transformers.
: 115 kV
: Dyn 1
Rated MVA output power,
Rated secondary voltage
On-load tapping voltage
Rated primary voltage
on primary side
Cooling method
Vector group
OLTC type

1050020002-  

II
1

Description
Invitation to Bid No.:
PEA
Catalogue
Material
No.
No.
Item
ManufacturCountry of Trade-mark
Quantitu1 lot
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
Specification No. RTRN-014/2559: ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION C4 Price schedule
Complete with current and voltage transformers, lightning arrester,
: +10% to -10% of nominal primary
: 23.1GrdY/13.3 kV (Wye-ground)
2.1 On-load tap-changing power transformer, three-phase, 50 Hz, with:
: 30/40/50, ONAN/ONAF1/ONAF2
discharge counter, cable termination kits, and other accessories.
voltage 1.25% in each step
: vacuum interrupter type
2.2 Supervisor(s) for installation the above transformers.
: YNyn0(d1)
: 115 kV
Rated MVA output power,
Rated secondary voltage
On-load tapping voltage
Rated primary voltage
Cooling method
on primary side
Vector group
OLTC type

1050020003-  

II
2

Description
Invitation to Bid No.:
PEA
Catalogue
Material
No.
No.
Item
ManufacturCountry of Trade-mark
Quantitu1 lot
PROVINCIAL ELECTRICITY AUTHORITY
TECHNICAL SPECIFICATION DIVISION
Specification No. RTRN-014/2559: ON-LOAD TAP-CHANGING POWER TRANSFORMERS FOR 115 kV SUB-TRANSMISSION C4 Price schedule
Complete with current and voltage transformers, lightning arrester, discharge counter, cable termination kits, and other accessories.
: +10% to -10% of nominal primary
: 23.1GrdY/13.3 kV (Wye-ground)
3.1 On-load tap-changing power transformer, three-phase, 50 Hz, with:
: 15/20/25,ONAN/ONAF1/ONAF2
voltage 1.25% in each step
: vacuum interrupter type
3.2 Supervisor(s) for installation the above transformers.
: 115 kV
: Dyn 1
Rated MVA output power,
Rated secondary voltage
On-load tapping voltage
Rated primary voltage
Cooling method
on primary side
Vector group
OLTC type

1050020004 -  

II
3

Description
Invitation to Bid No.:
PEA
Catalogue
Material
No.
No.
Item