ANSI C57.12.40 : 2011

Foreword
1 Scope
2 Referenced and related American National Standards
   2.1 Referenced American National Standards
   2.2 Related American National Standards
3 Transformer performance requirements
   3.1 Kilovolt-ampere ratings
   3.2 Voltage ratings and tap ratings
   3.3 Angular displacement
   3.4 Basic lightning impulse insulation levels
   3.5 Percent impedance
   3.6 Audible sound levels
4 Tests
5 Primary disconnect and grounding switch
   5.1 General
   5.2 Primary switch electrical performance requirements
   5.3 Primary switch mechanical features
   5.4 Primary switch accessory equipment
   5.5 Primary cable entrance
6 Construction
   6.1 General
   6.2 Corrosion resistance
   6.3 Tank
   6.4 Accessory equipment for transformer tanks
   6.5 Dimensions
7 Bushings
   7.1 Primary bushings
   7.2 Secondary bushings
   7.3 Terminal markings
8 Neutral termination
   8.1 Primary neutral
   8.2 Secondary neutral
9 Nameplate
10 Connections of transformer for shipment by the
   manufacturer

Gives certain electrical, dimensional, and mechanical characteristics and takes into consideration certain safety features of three-phase, 60Hz, liquid-immersed, secondary network transformers with a three position grounding switch, subway and vault types, rated 2500 KVA and smaller; primary 34400 volts and below; secondary 216Y/125 volts and 480Y/277 volts.