brucechase
Member
... Now that I've drawn it, I think that the 120 VAC supply for the interposing relay coil may be from another source - not that it should make any difference, since the common for the NO contact in the interposing relay is fed from the transformer.
It does make a BIG difference if you have the 120 VAC supply from one source and the neutral on another source - especially if none of the transformers are bonded to ground.
If this is the case, you need to get all the voltages on one system.
Is there a reason that you aren't grounding the 120 VAC? An ungrounded system is very hard for many people to troubleshoot since they just keep checking everything to ground - instead of the neutral.