Electrical Issue - GFI ok on Inverter - not on SP or Gen

and never in the RV, except possibly at the generator or the inverter
NEVER in the RV breaker panel

DrewE wrote:

MrWizard wrote:
of these GFI outlets can be reset and work from inverter power
But trip and will not work from shore or generator
You probably damaged the ats and there is a ground fault in the ats

It's almost certain that there's a ground fault somewhere downstream of the GFCI in question. If the ATS is upstream of it (i.e. if the GFCI is on one of the RV circuits, and the ATS switches the input to the RV electric panel as is common), then it's not the source of the problem.

The likely reason that the GFCI does not trip on inverter power is that the inverter does not bond neutral and ground, and so even though there's a ground fault no current flows through it as the ground doesn't provide an electrical path back to the inverter output. It's not likely to be a faulty GFCI in this case, in my opinion, since it does reset and apparently work on inverter power.

a GFI does NOT repeat NOT look at current in the ground lead. If that was all it did, it would seldom provide protection. What a GFI does is look at the DIFFERENCE in the hot and neutral current.

In fact a GFI will provide protection even on the old 2 prong outlets.

However, I would look carefully for a ground/neutral short downstream of the GFI. GFI will trip if they see ground and neutral bonded together downstream of the GFI.

with the inverter, the ground and neutral are not tied together upstream so the GFI may not be able to detect a ground/neutral bond downstream. But when connected to the shore power it will be able to detect a ground/neutral bond downstream and will trip. Ground and neutral should never be tied together except at the breaker panel

MrWizard wrote:
of these GFI outlets can be reset and work from inverter power
But trip and will not work from shore or generator
You probably damaged the ats and there is a ground fault in the ats

It's almost certain that there's a ground fault somewhere downstream of the GFCI in question. If the ATS is upstream of it (i.e. if the GFCI is on one of the RV circuits, and the ATS switches the input to the RV electric panel as is common), then it's not the source of the problem.

The likely reason that the GFCI does not trip on inverter power is that the inverter does not bond neutral and ground, and so even though there's a ground fault no current flows through it as the ground doesn't provide an electrical path back to the inverter output. It's not likely to be a faulty GFCI in this case, in my opinion, since it does reset and apparently work on inverter power.

of these GFI outlets can be reset and work from inverter power
But trip and will not work from shore or generator
You probably damaged the ats and there is a ground fault in the ats

maynardfam wrote:
Ran too much power to a 30 AMP Shore outlet.

Do you mean that you wired 240 volts to the outlet and then plugged in the RV?
If this is the case I would be replacing what does not work.

Yes - tried resetting the GFI. I'll work with the meter. Thanks for the advice!

I assume you mean that you were using too many appliances at the same time and overloaded the 30amp pedestal breaker, if this is the case then you may have damaged the GFCI(they are normally only 15 amp) but you're saying you don't have any power to that outlet. How do you know you don't have any power to the line side of the GFCI. If you really don't have power to the GFCI, then there is either a switch or CB that is blown.

Take your meter and check both the line side and the load side before you go any further. If there is 120 to the line side and it will not reset, buy a new GFCI, if there isn't go the breaker and see if it is hot on both side, keep going till you find power and the last thing you checked without power is the problem.

did you try resetting the GFI outlets? If not, do so.