Line fault at the outlet -- do I need an electrician?

Thanks, Jim. And I'm not doing anything without rereading these posts and triple checking things are dead. And if I'm even 10% uncertain, I'll just skip it!

But I'm learning a lot and so there's already been a payoff.

I ran out of time today, but I'm going to
(a) unplug all things on that chain
(b) measure again to see if the 4v are still there

Not really going the right way.  The voltage appears because you have a resistance on the neutral (bad connection or too thin a conductor) along with current (any other devices on it).

Lets say you use a perfectly good incandescent lamp, and you turn it on, and 4 V appears, off, it goes away.  The lamp is not bad.  The problem is the lamp is passing current (that's how these pesky electric devices work), and the resistance on the neutral is too high. Regardless of the device causing it, your problem is the wiring, not the device.

Best,


E

Hilde45, when you measured the 4 volts while the system was plugged in, were the components in the system turned on, or were they turned off or at least in standby? And as far as you know was anything else that is on the same branch turned on at the time?

If a lot of stuff was turned on at the time it increases the likelihood that the explanations cited by Erik and Jim apply. If not, it increases the likelihood that my hypothesis applies, namely that applying 120 volts to the AC neutral input of the component(s) resulted in excessive AC leakage to ground, mainly via their power transformers. Or, as heaudio123 alluded to, if significant current was being drawn by the components or other things the cause could have been a combination of both factors.

If my hypothesis was the main contributor, though, that issue should go away once the hot and neutral connections are reversed to what they should be.

Best regards,
-- Al

It could also be something as simple as a cracked receptacle causing a leak, I’ve seen some look pretty bad.

I have certainly enjoyed this thread as well. There has been a lot of good information suggested and this really points out the problems that can arise when this old house meets do-it-youselfer. I don't mind do-it-youselfer's as long as they get the doing part right. This also demonstrates the effectiveness of the Panamax unit and the importance of a dedicated circuit.