We do not happen to have this exact transformer in stock so we are answering based on other transformer we encounter.

From your message, the seconday connections are legible and you already know where you will be connecting the building’s three hot wires, to the transfomer at X1, X2 and X3.

The three primary coils are usually already pre-wired from the factory and connected in Delta, at the nominal voltage, in your case 480V.

This could be H1, H2 and H3 referring to a similar Westinghouse transformer we have in stock. These points would form the three corners of the triangle or Delta and be the locations where you would take off the 480 Volts needed for your load.

Other connections on each phase coil are the primary taps that were below nominal (on our particular Westinghouse transformer) and would be may be in the form of a terminal or discrete wires brought out from the coil. These can be covered or capped off as they would not be needed.

Make any and all connections to the transformer while all possible power sources to the transformer have been removed. Always wear safety glasses when you energize the transformer.

Again please be careful.

Respectfully,

Larry V. Dahlgren
Electrical Power Engineer
MIDWEST
414.931.0992 / 414.461.8485 Fax
larryd@swgr.com