I intend to use this generator for ham radio and emergencies, but maybe some RVers can shed some light since I'm scratching my head.New Predator 4000 generator. Has two GFCI outlets on it. Plug in halogen work lights, works great. Plug in the laptop computer, works great. Plug in a surge protected outlet strip, works great. Plug the laptop into the surge protector while it's plugged into the generator, and it will trip the GFCI (either outlet). Plug the same surge protector and laptop combination into the GFCIs in the house, and there's no problem. Only on the generator, and only when the laptop and surge protector are combined. A 3-light GFCI outlet tester shows no problem with the outlets, and pressing the test button trips them.Generator is not tied to earth ground (yet), could that be the problem? GFCIs don't need a ground to work, and I've not heard of them not working properly without one.

Doesn't need earth ground. You need to lie to the genset by installing a dummy plug into it's receptacle with a jumper between ground and the neutral.

enblethen wrote:Doesn't need earth ground. You need to lie to the genset by installing a dummy plug into it's receptacle with a jumper between ground and the neutral.Actually, the generator already has neutral and ground joined behind the panel. The outlet tester shows this and I confirmed with an ohmmeter.

enblethen wrote:Doesn't need earth ground. You need to lie to the genset by installing a dummy plug into it's receptacle with a jumper between ground and the neutral.I don't think that would help in this case. In fact, it should trip the GFCI on the generator to tie the neutral and ground together by plugging in a bonding plug since that would be a neutral/ground fault after the GFCI (and modern GFCIs have circuitry to detect that kind of fault even in the absence of significant fault current).It seems that there's something about the combination that is fooling the GFCI. I'd probably lose the surge suppressor and just use a plain outlet strip or multi-tap if needed. There shouldn't be much chance for big surges from a generator if you aren't powering any big inductive loads or having a large power distribution network.

I'd guess that the combination of the outlet strip and laptop produces enough leakage to the ground wire to trip the gfci. Why doesn't it trip the home gfci? Easy answer: The generator gfci has a lower trip threshold than the home gfci. More likely answer: Not being an inverter generator, the sine wave output waveform is likely distorted, resulting in the laptop and surge protector's leakage to exceed the gfci trip threshold. Forget the bonding plug. If the neutral wasn't already bonded, the gfci would never trip.

Generator GFCI trouble | Good Sam Community

15 Replies

road-runner
Explorer III
Jun 19, 2018
I'd guess that the combination of the outlet strip and laptop produces enough leakage to the ground wire to trip the gfci. Why doesn't it trip the home gfci? Easy answer: The generator gfci has a lower trip threshold than the home gfci. More likely answer: Not being an inverter generator, the sine wave output waveform is likely distorted, resulting in the laptop and surge protector's leakage to exceed the gfci trip threshold. Forget the bonding plug. If the neutral wasn't already bonded, the gfci would never trip.
time2roll
Nomad
Jun 19, 2018
Don't use the surge protector.
DrewE
Explorer II
Jun 19, 2018
enblethen wrote:
Doesn't need earth ground. You need to lie to the genset by installing a dummy plug into it's receptacle with a jumper between ground and the neutral.

I don't think that would help in this case. In fact, it should trip the GFCI on the generator to tie the neutral and ground together by plugging in a bonding plug since that would be a neutral/ground fault after the GFCI (and modern GFCIs have circuitry to detect that kind of fault even in the absence of significant fault current).

It seems that there's something about the combination that is fooling the GFCI. I'd probably lose the surge suppressor and just use a plain outlet strip or multi-tap if needed. There shouldn't be much chance for big surges from a generator if you aren't powering any big inductive loads or having a large power distribution network.
sparkydave
Explorer
Jun 19, 2018
enblethen wrote:
Doesn't need earth ground. You need to lie to the genset by installing a dummy plug into it's receptacle with a jumper between ground and the neutral.

Actually, the generator already has neutral and ground joined behind the panel. The outlet tester shows this and I confirmed with an ohmmeter.
enblethen
Nomad
Jun 19, 2018
Doesn't need earth ground. You need to lie to the genset by installing a dummy plug into it's receptacle with a jumper between ground and the neutral.

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Generator GFCI trouble

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