Installing Solar Electric Since 1983


Background: We purchased a transformer to connect across two phases of a three phase generator like this:

Transformer 1

Whe we installed the transformer, we jumpered X2 and X3 as described by the transformer placard:

Transformer 2

We terminated X1 and X4 in a circuit breaker, but for testing, we left the circuit breaker open. When we energized the transformer, the generator bogged down and by the time we stopped the generator, the tranformer was warm.

We double checked our connections and found they were correct. We speculated that the windings were labelled incorrectly and we checked that with an ohm meter. Just as we suspected, terminals X2 and X3, instead of being the ends of separate windings were ends of the same winding. In effect, we had created a direct short circuit on the output of the tranformer, like the diagram below:

Transformer 3

We contacted Hammond Power Solutions and talked with Dave, Tom, Rob and Susan. We corrected the wiring and placed the transformer in service. On week later, the transformer failed. It got very hot, leaked fluid and began exhibiting a direct short to the generator.

We would like to return the transformer for a full refund, including shipping.


William Miller