RV GFCI Trips On Generator Power

[fingerlakes freelance]

A little help?

Our motor home gfci outlet feeds the outlets on the passenger side of the coach (two baths, kitchen, and tv).

Works fine when running on shore power. Trips immediately, but not always, when running on generator power, disconnected from shore power.

My RV repair shop tried troubleshooting but failed. They did say that the gfci does NOT trip on the generator IF the inverter is disconnected.

That doesn't seem to make sense to me?

 

[Dennis Alwon]

I am allowing this since the owner is looking for advice not diy.

 

[hbiss]

You can't compare generator power to utility power. It's dirty and unstable which does strange things to electronics.

Probably more importantly- why an inverter and a generator and why at the same time?

-Hal

 

[fingerlakes freelance]

You can't compare generator power to utility power. It's dirty and unstable which does strange things to electronics.

Probably more importantly- why an inverter and a generator and why at the same time?

-Hal

To be honest Hal, I am not sure how all the logistics on the RV work - the motorhome is new (to us), and we are still learning the ropes.

I do know that there is a transfer switch that automatically switches between shore power and generator power (if the generator is running).

I am not sure how the inverter is implemented, or when - I'm guessing that there is a transfer switch for that too?

I would expect it to run ONLY if there is no generator AND no shore power.

I have not spoken directly with the tech that is troubleshooting the unit - the comment about the gfci not tripping when the inverter was disconnected came from the service manager.

He's wanting to know how much more time ($$) I am willing to spend to have his service tech continue troubleshooting.

:weeping:

 

[fingerlakes freelance]

I am allowing this since the owner is looking for advice not diy.

Thank you!!

 

[kwired]

Does it matter if any loads are turned on/plugged in when this is happening?

Some sort of inductive kickback or other unknown abnormality is maybe causing GFCI to trip. Small generator power isn't always the "cleanest power" and may contribute to this. Though inverter output generators that are starting to become more common should have cleaner power (if you have one of those).

The inverter likely automatically senses if there is AC voltage and electronically shuts down it's output when there is other AC voltage present. Your generator may not put out steady enough AC voltage and the inverter is putting spikes on the line trying to decide what to do. Not the most technical way to explain it but I think maybe good enough to get some idea of what possibly is happening, basically your inverter and generator maybe don't play well together for some technical reason.

 

[Adamjamma]

to be honest with you, my dads RV in the eighties, well, seventies and eighties, had an inverter and he used a generator on it sometimes... We learned not to leave the inverter on when running the generator, as the generator was supplying the energy to the camper... for some reason, when we plugged in the shore powerr, the inverter was automatically switched off... but when we plugged in the generator, the inverter had to manually be switched off.

My dad had a buddy install a switch that took a key onto the inverter circuit, and later just took it out, because he could never charge the batteries on shore power or on the generator, and had one or the other in use when we were parked at night and needed lights.
Other than that, cannot help you...Inverter would be more for running stuff from storage batteries when do not want to run generator or hook up at a campground...

 

[Craigv]

The inverter may have a ground fault. The OP did not state whether he has run only the inverter for AC power.


Note that some inverters double as house-bank battery chargers and should be on when shore power or generator power are active.

Check to see whether there is a separate battery charger for the house bank. Find the make and model # of the inverter. The year, make and model of the RV couldn't hurt...there may be schematics available, or an operator's manual. Got a hard copy of it?

 

[kwired]

The inverter may have a ground fault. The OP did not state whether he has run only the inverter for AC power.


Note that some inverters double as house-bank battery chargers and should be on when shore power or generator power are active.

Check to see whether there is a separate battery charger for the house bank. Find the make and model # of the inverter. The year, make and model of the RV couldn't hurt...there may be schematics available, or an operator's manual. Got a hard copy of it?

But the inverter, generator and/or shore power should all be on supply side of the GFCI that is tripping. Unless the generator somehow has a inadvertent connection to the load side of the GFCI it shouldn't matter unless there is inductive kickback on the circuit or some RF interference is somehow developed that the GFCI doesn't play well with. Such anomalies would have to be related to the generator itself though, or same thing should happen when running on shore power.

 

[Craigv]

But the inverter, generator and/or shore power should all be on supply side of the GFCI that is tripping. Unless the generator somehow has a inadvertent connection to the load side of the GFCI it shouldn't matter unless there is inductive kickback on the circuit or some RF interference is somehow developed that the GFCI doesn't play well with. Such anomalies would have to be related to the generator itself though, or same thing should happen when running on shore power.

Adding the inverter to the circuit trips the GFCI, so the likelihood seems greater that it, and not the genny, have the load-side fault. As there are inverter/chargers, if this unit is dual function it may have a separate charger feed on the line side of the GFCI. Or the feed/output may have a fault. That's why I'm asking OP for make/ model and hopefully some schematics of the RV wiring, and also for whether the inverter alone trips the GFCI. We don't have enough information to do more than vague speculation at this point.

edit to add: it's possible there are problems in both the genny and the inventor, and when both are in the circuit it's enough to trip the GFCI. But again, we need more info.

 

[102 Inspector]

I have found that websites specific to RV's and Travel trailers offer a lot of good advise. I use iRV2.com for my questions. You might check out forums related to Rving for more advise. Good Luck.

 

[kwired]

Adding the inverter to the circuit trips the GFCI, so the likelihood seems greater that it, and not the genny, have the load-side fault. As there are inverter/chargers, if this unit is dual function it may have a separate charger feed on the line side of the GFCI. Or the feed/output may have a fault. That's why I'm asking OP for make/ model and hopefully some schematics of the RV wiring, and also for whether the inverter alone trips the GFCI. We don't have enough information to do more than vague speculation at this point.

But also runs fine on shore power, and am presuming inverter is still connected in same manner when this happens. About has to be a combination of things involving both the inverter and the generator. Still thinking interaction between the two doesn't play well with the GFCI that is tripping - and both are very likely on the line side terminals of the GFCI, which starts to point to some kind of "noise" that gets into more technicalities to try to understand, but is happening between the inverter and the generator when both connected to the system.

Seems from what has been said GFCI is fine running on inverter or on the generator, but don't like both in the system at same time.

I'm not saying something is wrong with either one of those - just that for some reason they don't play well together.

 

[Craigv]

But also runs fine on shore power, and am presuming inverter is still connected in same manner when this happens. About has to be a combination of things involving both the inverter and the generator. Still thinking interaction between the two doesn't play well with the GFCI that is tripping - and both are very likely on the line side terminals of the GFCI, which starts to point to some kind of "noise" that gets into more technicalities to try to understand, but is happening between the inverter and the generator when both connected to the system.

Seems from what has been said GFCI is fine running on inverter or on the generator, but don't like both in the system at same time.

I'm not saying something is wrong with either one of those - just that for some reason they don't play well together.

Thing is, we don't even know whether the inverter is connected when shore power is on...it's very likely, but not certain, as a there's probably a selector/transfer switch and who know how it wired. Gotta get more info.

 

[kwired]

Thing is, we don't even know whether the inverter is connected when shore power is on...it's very likely, but not certain, as a there's probably a selector/transfer switch and who know how it wired. Gotta get more info.

OP did mention there is (apparently automatic) transfer switching from shore power to generator power, did mention not sure how inverter is integrated into system. I don't know what is typical for RV's either. Something tells me it is a little like PV system inverters and is electronically controlled though. Don't know if it would drive a real isolation contact or if it would be done with solid state switching. May not like unstable frequency that may come from a generator either.

 

[Little Bill]

3 year old thread