park GFI outlets and inverters

[cody]

OK, time for another dumb question, this is one for the electricians, why don't GFI outlets on the park power posts work with an inverter equiped bus, we've seen this several times at parks this summer, as soon as you plug in, it pops, not only with our bus but happened to every bus at 3 differrent parks.  Each one that took the time to put in a regular outlet for us had it work just fine after it was installed.  I thought it might be my wiring but my wiring checked out when I had it looked at by an electric tech at an RV shop, he said he's seen that too.

[Brian Diehl]

I think it has to do with the noise supression.  My Outback inverter will trip some GFCI outlets and not others.  Outback told me there is a 50 picofarad? capacitor between the neutral and ground for noise supression.  I assume this is why I have problems.  When I'm at a camp like that I end up just disconnecting the ground at the inverter.  Not a great solution, but the only one I could come up with and still have power to charge and pass through to my inverted appliances/outlets.

[TomCat]

My electrician put a 50a GFI on my home power pod, and it will trip every time I plug into it. All I do it reset the breaker, turn it on again and all is good. I figured it was my transfer switch doing it's thing, which caused the GFI to trip.
A minor inconvience to me.

Jay
87 SaftLiner

[Ncbob]

Cody, I might have 'goofed' in bringing up an old thread in answer to your inquiry.  Blame it on age!

A good tool to have with you at all times is a "Wiggy", an AC tester to make sure that the flow of power is from the right direction in relation to the neutral (read negative).  The service ground should (like the neutral) should always be common with earth, although in reality it goes back to the supplier.

Maintenance people in some older campgrounds, while well intentioned, don't always get the 'polarity' correct.

Bob

[cody]

Bob, my first thought when we popped the GFI at the first park was a bad outlet, but after talking to the other bus owners, I found out that they had all popped the breaker on their power posts, and all had inverters, the next park same problem and same equipment, again at the third park, just struck me as strange, like my wife tells me, expiring minds want to know lol.  Only one campground had what would be an older system, the other 2 were newer campgrounds with supposedly new wiring.  One guy told me that inverters and GFI outlets wern't compatable, it appeared that way to me, just seemed strange.

[Len Silva]

If you are tripping the GFI then somewhere, somehow, there is a "leak" between neutral and ground.  If you measure with an ohmmeter on your plug the resistance should be infinity between those two points.

A GFI works by comparing the current on the hot lead with the current on the neutral lead.  If they are not exactly the same, it assumes that some current is going to ground and it trips.

It wouldn't take much, a filter capacitor will do it.

Len

[cody]

If it was just my bus I would understand, but what confused me was that all the busses had the same problem, and at 3 parks, do we all have a wiring leak? or are all the posts wired wrong? I don't know it just seemed strange to me that we would all have the same problem, not only there but at other parks too, afterwards I had my system tested because I thought maybe I had a problem but it tested out ok.  Could it be that the nature of an inverter creates a flux in the current that the GFI read as a ground fault?  The rigs that had converters instead of inverters worked fine.

[H3Jim]

Sean had replied here several months ago about this same issue, it seems that his inverter is what trips it.  Apparently GFI are so sensitive, that initial "leak" is enough to trip it.  Sean also had to replace the outlet with a non GFI unit in order to use his inverter.  I can't remember any more details though...

[gumpy]

Yeah, this is a known issue. It's related to the internal capacitance and the ground bond internal to the inverter. Sean posted a lengthy post some time ago regarding his SW4024 inverter. I have the same inverter, and have the same problem.  In July, I installed a new inverter in my Father-In-Law's trailer, and had the same problem with the GFCI outlets on his house. I'd had problems with his GFCIs and my SW4024 at one time, too. The solution was to disconnect the internal ground bonding to the case within the inverter, and route it through a toggle switch which is external to the inverter. Now, when he comes across a GFCI that trips when he plugs in, he simply flips the toggle switch, plugs in, and then resets the toggle switch back to normal. Works just fine and you only need to switch the ground bond until it's plugged in, as the problem only occurs at the instant you plug in.

craig

[Charles in SC]

I removed the bonding screw in the breaker box and set it up so that all the grounds were on one side and the neutruals were on the other side. I have not had a problem since. I do not think the inverter has anything to do with it. Just my .02 cents worth.

[gumpy]

Charles,

Your breaker box is not supposed to have the neutral and ground bonded anyway, unless you only power your coach off the
inverter and never plug into shore power or run a generator. So you corrected an incorrect wiring in your coach and solved
the problem it was causing.

The inverter does have something to do with it. It's been shown time and time again. And the solution is simply to put a switch
on the ground bond to the inverter case. This may not be the only reason a GFCI will trip, as pointed out my others, but it is certainly a prime cause of it, and something many others have had to deal with.

craig