IEEE C57.12.50 : 1981
Withdrawn
A Withdrawn Standard is one, which is removed from sale, and its unique number can no longer be used. The Standard can be withdrawn and not replaced, or it can be withdrawn and replaced by a Standard with a different number.
10-17-2023
01-01-1981
1. Scope
1.1
1.2
1.3
1.4
1.5
2. Related Standards and Guides
2.1 General
2.2 Terminology
2.3 Revision of American National Standards Referred
to in This Document
Part I: Basic Electrical and Mechanical Requirements
3. Usual Service Conditions
4. Ratings and Characteristics
4.1 Kilovolt-Ampere Ratings
4.2 Kilovolt-Ampere and Voltage Ratings
4.3 Taps
4.4 Insulation Levels
4.5 Polarity, Angular Displacement, and Terminal
Markings
4.6 Impedance Voltage
5. Construction
5.1 Insulation System
5.2 Accessory Location
5.3 Nameplate
5.4 Transformer Connections
5.5 Tap Changing
5.6 Lifting Facilities and Stability
5.7 Grounding Facilities
5.8 Transformer Enclosure
6. Routine Tests
7. Tolerances
Part II: Other Requirements or Alternatives That May Be
Specified for Some Applications
8. Other Ratings and Characteristics
8.1 Other Kilovolt-Ampere Ratings
8.2 40 degree C Average Ambient Temperature
Conditions
8.3 Other Winding Temperature Rises
8.4 Other Insulation Systems
8.5 Other High-Voltage Ratings and Connections
8.6 Y-Y Connected Transformers
8.7 Increased Neutral Insulation
8.8 Other Basic Lightning impulse Insulation Levels
(BILs)
9. Other Construction
9.1 High-Voltage Connection Arrangements
9.2 Low-Voltage Connection Arrangements
9.3 Surge Arresters
9.4 Unit Substation
9.5 Temperature Devices
9.6 Forced-Air Cooling
9.7 Provision for Future Forced-Air Cooling
9.8 Space Heaters
9.9 Current Transformers (or Provision for Their
Addition in the Future)
9.10 Terminal Blocks
9.11 Contacts
9.12 Jacking and Moving Facilities
10. Other Tests
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