Padmount Supply

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12470 GY/7200 V to 480Y/277 V transformer

A step down transformer with a 26 to 1 ratio. The standard pad mounted distribution transformer in most of the US. The utility brings 12470 volts to the property line and this unit produces the building service.

Primary12470 GY/7200 V
Secondary480Y/277 V
Ratio26 to 1
DirectionStep down
Common range45 to 2500 kVA

What to check before ordering

This is the workhorse rating we sell. 12470 GY/7200 means a grounded wye system at 12470 V line to line and 7200 V line to neutral. Most units are ordered with a 13200 tap so one build serves both common distribution voltages.

Current at each rating

Three phase full load current on both sides of a 12470 GY/7200 V to 480Y/277 V transformer. The higher voltage side always carries less current for the same kVA.

kVA12470 GY/7200 V side480Y/277 V side
150.7 A18.0 A
301.4 A36.1 A
452.1 A54.1 A
753.5 A90.2 A
112.55.2 A135 A
1506.9 A180 A
22510.4 A271 A
30013.9 A361 A
50023.1 A601 A

Nameplate full load current, computed from the standard three phase formula. Free to cite with a link to this page. For any rating not listed, use the kVA to amps calculator.

Common questions

What transformer do I need to go from 12470 GY/7200 V to 480Y/277 V

A step down transformer with a 26 to 1 ratio. The standard pad mounted distribution transformer in most of the US. The utility brings 12470 volts to the property line and this unit produces the building service. Most units for this conversion fall in the 45 to 2500 kVA range.

How many amps does a 12470 GY/7200 V to 480Y/277 V transformer draw

It depends on the kVA. At 100 kVA the 12470 GY/7200 V side carries about 4.6 amps and the 480Y/277 V side about 120 amps. Current is kVA times 1000 divided by the voltage times the square root of three, so the higher voltage side always carries less current for the same kVA.

What should I check before ordering

This is the workhorse rating we sell. 12470 GY/7200 means a grounded wye system at 12470 V line to line and 7200 V line to neutral. Most units are ordered with a 13200 tap so one build serves both common distribution voltages.

Other conversions