scope:

This standard covers certain electrical, dimensional, and mechanical characteristics of 50 Hz and 60 Hz, two winding, liquid-immersed distribution substation transformers. Such transformers may be remotely or integrally associated with either primary and secondary switchgear or substations, or both, for step-down or step-up purposes rated as follows:

a) 112.5 kVA through 10 000 kVA three-phase

b) 250 kVA through 6667 kVA single-phase

c) High voltage 69 000 V and below and low voltage 34 500 V and below

It is not intended that this standard shall apply to dry-type, regulating, pad-mounted, secondary-network, furnace, rectifier, mobile, railway, or mine transformers.