ECN Forum Forums General Topics of the Trade General Discussion Area Mysterious Shock

Both good points ... and I thank everyone for not automatically questioning my sanity / sobriety / etc.

As every government-funded study concludes .... wait for it ... "more study is needed"

Perhaps I will some day be able to re-visit this equipment, and have the appropriate equipment for measurement. Alas, that's not likely to happen ... it seems one cannot simply shut down one of these heat pumps without causing all manner of mayhem. There's a need to call an off-site monitoring/control service, etc.

How much is a 'tingle?' Well, GFCI studies suggest something around 3mA.

Autotransformer? That's again pointing me at the connections in their "special" transformers. You know ... all these years in the field, and I'm STILL not sure of the proper way to connect / ground an ordinary transformer! It seems every employer has had a different practice.

I'm still baffled as to how anything can get 'past' the circuit breaker. Unless, of course, this IS current induced by other circuits.

If the problem is in the neutral, it will certainly get past the breaker and with the breaker open, it will use the load as the path to the ungrounded conductors.
You could check that with everything running. Is there voltage between the neutral and ground? Then the question becomes "which ground"?

This time of year, with sweat dripping off your nose, a few volts will tingle you. I got lit up on my 36v golf cart.

Sounds like a ground/bond possible issue is the popular consensus.

The 'ghost' (induced) voltage has 'tingled' me a few times over the years. The voltage on the neutral can be a real 'kick' under the right conditions.