Table of Contents

1 Overview
   1.1 Scope
   1.2 Purpose
2 Normative references
3 Definitions
4 Usual service conditions
5 Ratings and characteristics
   5.1 Kilovolt-ampere ratings
   5.2 Kilovolt-ampere and voltage ratings
   5.3 Taps
   5.4 Insulation levels
   5.5 Angular displacement and terminal markings
   5.6 Percent impedance voltage
6 Construction
   6.1 Insulation system
   6.2 Accessory location
   6.3 Nameplate
   6.4 Transformer connections
   6.5 Tap changing
   6.6 Lifting, jacking, and moving facilities
   6.7 Ground pad
   6.8 Transformer enclosure
7 Routine tests
8 Tolerances
9 Other ratings and characteristics
   9.1 Forced-air-cooled ratings
   9.2 40 Degree C average ambient temperature conditions
   9.3 Other winding temperature rises
   9.4 Other temperature class insulation systems
   9.5 Other high-voltage ratings and connections
   9.6 Y-Y connected transformers
   9.7 Increased neutral insulation
   9.8 Other basic lightning impulse insulation levels
10 Other construction
   10.1 High-voltage connection arrangements
   10.2 Low-voltage connection arrangements
   10.3 Surge arresters
   10.4 Unit substation application
   10.5 Temperature devices
   10.6 Forced-air cooling
   10.7 Provision for future forced-air cooling
   10.8 Space heaters
   10.9 Current transformers (or provision for their addition
         in the future)
   10.10 Terminal blocks
   10.11 Contacts
11 Other tests
Annex A (informative) Bibliography

Abstract

Presents characteristics relating to performance, limited electrical and mechanical interchangeability, as well as safety of the equipment described, and to assist in the proper selection of such equipment.

General Product Information

Published
Document Type	Standard
Status	Current
Publisher	Institute of Electrical & Electronics Engineers
Pages
ISBN
Supersedes	ANSI C57.12.51 : 2008