Today we encountered a problem and have not found a solution yet any ideas would be appreciated.
The situation is this: while working on a large pump panel with several motor starters that are controlled at 120VAC from a control Xfmr 480 – 120 we noticed a voltage of 120VAC from its derived neutral to equipment ground. Actually one of the electricians got a jolt.
My first thought was that the secondary was not grounded so we checked and it was but the OEM had only bolted a ground to the transformer case so we ran a ground to our equipment ground to make sure of a good connection. No luck still 120VAC to ground on the neutral. We double-checked the connections and it seems to be wired properly. I believe it is fed H1 & H4, H2 & H3 Connected and insulated. Then for the secondary, which can be 120 or 240, is wired X1 & X3 connected and run to ground X2 & X4 fused. Should it be reversed X1 & X3 “hot” X2 & X4 Neutral? I don’t think it matters am I wrong?
Some other observations are that this control feeds thru a GFCI to when we check the neutral to ground voltage with something like a “Wiggy” we trip the GFCI?
Any suggestions would be appreciated.
Thanks
Rich
