OT - Intermittent control voltage transformer?

[brucechase]

... 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.

 

[tracer]

twice I have seen a transformer blow up. both times due to massive overload, one was a control x-fmer (around 1 kva I think) one of the mechanics, kept adding circuits to the 120V secondary side, output should have been fuzed at approx 8 amps or so. he had 4 separate circuits 2 of which were wired to receptacles, he at least did have fuzes on each circuit, but the amp total for all 4 was somewheres around 32 amps. no wonder it went boom.........lol
also check the fuzes, my mechanics only recognize replacing any fuze with a 30amp one. if the x-fmr is burning up as soon as it's powered up, check your primary leads, for correct voltage. check output voltage of x-fmr with all secondary leads disconnected.