IEC/ANSI Standard Oil Immersed Power Distribution Transformer

Service condition

Normal Condition

Ambient temperature

Indoor

-5°C to +40°C

Outdoor

-10°C to +40°C

Humidity

90%

Altitude

≤1000m

Pollution

Level I-Light

Level II-Medium

Earthquake

UBC Zone 3

Special Condition

Ambient temperature

Indoor

-15°C to +40°C, -25°C to +40°C

Outdoor

-10°C to +50°C, -25°C to +40°C

-40°C to +40°C

Humidity

95%, 98%

Altitude

≤2000m, ≤3000m, ≤4000m

Pollution

Level III-Heavy

Level IV-Very Heavy

Earthquake

UBC Zone 4

K-factor

3, 5, 7, 9, 11, 13, 15, 17

Standard code

IEC 60076-1 Power transformers-Part 1: General

IEC 60076-2 Power transformers-Part 2: Temperature rise

IEC 60076-3 Power transformers-Part 3: Insulation levels, dielectric tests and external clearances in air

IEC 60076-4 Power transformers-Part 4: Guide to the lightning impulse and switching impulse testing

IEC 60076-5 Power transformers-Part 5: Ability to withstand short circuit

IEC 60076-10 Power transformers-Part 10: Determination of sound levels

IEC 60076-11 Power transformers-Part 11: Dry-type transformers

IEEE C57.12.00 General Requirements for Liquid-Immersed Distribution Power, and Regulating Transformers

Ratings

IEC

Rated Frequency

50Hz, 60Hz

Rated Voltage

3.6 kV – 7.2 kV – 12 kV – 17.5 kV – 24 kV – 36 kV

Rated Insulation Level

20kV – 40kV – 60kV – 75kV – 95kV – 125kV – 145kV – 170kV

Rated KVA

30kVA – 50kVA – 80kVA – 100kVA – 125kVA – 160kVA – 200kVA – 250kVA – 315kVA – 400kVA – 500kVA – 630kVA – 800kVA – 1000kVA – 1250kVA – 1600kVA – 2000kVA – 2500kVA – 3150kVA

IEEE

Rated Frequency

60Hz

Rated Voltage

2.5kV – 5.0kV – 8.7kV – 15.0kV – 25kV – 34.5kV

Rated Basic Impulse level

30kV – 45kV – 60kV – 75kV- 95kV – 110kV – 150kV – 200kV

Rated KVA

Single-phase transformer:

5kVA – 10kVA – 15kVA – 25kVA – 37.5kVA – 50kVA – 75kVA – 100kVA – 167kVA – 250kVA – 333kVA

Three-phase transformer:

15kVA – 30kVA – 45kVA – 75kVA – 112.5kVA – 150kVA – 225kVA – 300kVA – 500kVA – 750kVA – 1000kVA – 1500kVA – 2000kVA – 2500kVA – 3750kVA