Off grid solar system a/c small shock

[travelinman96]

I have a 1000 watt solar setup, charge controller, inverter, batteries etc. The panels are grounded to a custom metal frame and the inverter is grounded to and earth ground. I have two a/c circuits in the house and some electrical cords (example laptop adapter) will sometime give you a small electrical shock if you touch the metal on the adapter. Trying to troubleshoot, any ideas? Thanks

[inetdog]

I have a 1000 watt solar setup, charge controller, inverter, batteries etc. The panels are grounded to a custom metal frame and the inverter is grounded to and earth ground. I have two a/c circuits in the house and some electrical cords (example laptop adapter) will sometime give you a small electrical shock if you touch the metal on the adapter. Trying to troubleshoot, any ideas? Thanks

Is the inverter a Pure Sine Wave (PSW) or a Modified Square Wave (MSW) type?
Some MSW inverters run the neutral at a voltage of about 60V to ground. Think of the design as a center tapped 60-0-60V transformer with the center tap grounded.
Some devices have a low leakage impedance between their ground (EGC) lead and the neutral. This normally does not cause any problems because there is a low voltage between neutral and ground in a grid supplied system.
When used with an MSW inverter they can cause problems.
An actual bond between neutral and ground, as is required at the service disconnect in grid-sourced wiring in the US, will cause a solid short circuit and let all of the magic smoke out of the inverter.

If you do not have a voltmeter and a minimum amount of electrical knowledge on how to use it you can get a very unsafe situation. Be careful and get qualified help as necessary.

[travelinman96]

It is in fact a modified sign wave inverter made by aims. The light switches in the system have also shocked at the metal screw. Do you believe this also to be because if the modified sign wave inverter? Would a pure sign wave inverter solve this issue? What steps with a volt meter would you take to find the problem? Thanks

[bcroe]

I am going to take a guess and say maybe its not the solar. Long ago I washed dishes and the counter had a metal strip at the
edge. If I laid my arm on the metal, esp if I had a scratch there, I'd get a mild shock. I tied all the metal together in the area,
esp the water pipes and the drain pipes, and stopped the shocks. I concluded some small voltage was either induced by house
wiring or caused by chemical action, which I shorted out. Sorry, no scopes or meters in my life back then. Bruce Roe

[Mike90250]

stop, turn it off and call a qualified solar electrician. We don't want you to die, and can't fix it over the internet,.
This problem is like filling the petrol tank in a car, the fuel is overflowing all over, and you have a lit match.

[inetdog]

It is in fact a modified sign wave inverter made by aims. The light switches in the system have also shocked at the metal screw. Do you believe this also to be because if the modified sign wave inverter? Would a pure sign wave inverter solve this issue? What steps with a volt meter would you take to find the problem? Thanks

If and only if the problem is the one that I described, then changing to a PSW will resolve it.
Not all MSW inverters behave this way either.
But we still cannot say for sure that is even the problem.
The key, as Mike stated, is that resolving the problem correctly and for good can only be done by an electrician who understands solar or at least inverters and is on-site able to look and measure.