Transformer Theory
Transformer Theory
(OP)
Would like to get some instruction on wiring a 240/110 transformer. Our shop is constantly discussing the proper grounding method for the transformer secondary. E.G.: We have 240VAC, 3PH, 3-wire coming into a breaker panel. One of the breakers feeds a 1KV 240/110 transformer. Since there are only three wires coming into the breaker panel, how is a neutral obtained on the secondary side of the transformer? And what about grounding? I know this is basic stuff, but this application exists on a trailer and it doesn't look right to me. The 240 panel has no ground bus bar. It also has a neutral bus bar but nothing is connected to it? Some transformer theory would be appreciated.
alc
alc






RE: Transformer Theory
Neutrals on both sides of a transformer are electrically independent although they are generally interconnected. You can get only a neutral on a Y connected secondary even the primary is delta connected.
There is another way to obtain a neutral when Y connection is not possible or when mains is three wires. In such a circunstances you must use an special three phase coil with zig-zag connection.
For more details let me know.
Julian
RE: Transformer Theory
"UNGROUNDED DELTA" and "TWO-WIRE" describe the transformer configuraions you describe.