I have a machine that needs 400 volts phase to phase, 230 volts to neutral. So a transformer with a Y on one side is needed.
I purchased a used 30 KVA 208/240 2 phase transformer. 208Y 240 delta. That is a .866 ratio. 480 * .866 = 416. Close enough. I connected it backwards to 208 first, in measured was 217 and out was in the range of 270. OK transformer is good it appears. Then I connected the delta side to 480 (my shop has 480, 240 & 208 three phase panels). It blew the breaker. So I connected to the Y side. It blew the breaker. I lifted each leg and it blows the breaker. Taking it back to the 208 circuit to check for shorts as the winding resistance is so low I don’t have a meter to read it. Anyone have any thoughts?
