Inverter GFCI pops for no apparent reason

[geokeg]

My inverter has no output.  It turns on, but there is no output due to the GFI breaker opening.  If  I turn the inverter off, reset the GFI, it pops again about 3 seconds after turning the inverter back on.  This even happens with the output cord disconnected from the inverter.  This looks like a faulty GFI  to me or an internal inverter fault. Has anyone else experienced this failure or have a recommendation of action.  There are no fault codes and input voltage to the inverter is 13.9 as read on the inverter display.  The inverter thinks it is fine but the GFI does not.

[ScubaRx]

That sounds like an internal neutral/ground fault. When the neutral and ground come together in our trailers it will blow a GFI Outlet.

[geokeg]

What seems weird to me is that the inverter was working fine.  The trailer has not moved since the inverter last worked and now it does not. I had a 115/120 power source hooked to the trailer over the winter to operate a space heater.  No problems with any of that.  Now with shore power disconnected and batteries at 100 % the GFI trips, while disconnected from providing any output.  The failure mode baffles me.  The inverter seems to have become internally faulted, without any external cause.  Maybe internal moisture due to condensation?

[mountainoliver]

You said that you used a space heater this winter. Check inside of the metal junction box that’s close to the inverter. It’s a standard household 4in square galvanized box. Mine and a few others have had a similar problem as you. Mine turned out to be a bunch of loose connections inside this box. One of the wires and it’s wire nut completely melted into. Luckily in mine nothing touched the box. There are solid house type wires connected to stranded wire with wire nuts. It’s difficult to get a solid connection with solid and stranded wire together in a wire nut. Don’t just check the wire nuts for tightness but remove each nut and check that all of the wires are actually in the nut. There could be a short inside this box so make sure that ALL power is off before even touching the metal box as a hot wire may be against the box. This may not be your specific problem but it’s an easy thing to check.

[geokeg]

My GFI is tripping with nothing connected to the inverter to draw power.  The outlet cord is physically disconnected.  I have the battery positive and negative wires plus the “phone/com” cable going to the remote control panel connected to the inverter. Nothing else is connected to the inverter to show up as a ground fault and trip the breaker.  The inverter is essentially isolated from any source that could be providing a ground fault signal through the inverter power output circuit.  I am thinking the GFIC has failed or an internal inverter fault.

[BackofBeyond]

I would start there - the inverter and the GFCI. If you can replace the plug, do that, if problem persists, its probably an inverter issue. But as has been suggested, verify all connections are sound. Good luck.

[Mike and Carol]

You said that you used a space heater this winter. Check inside of the metal junction box that’s close to the inverter. It’s a standard household 4in square galvanized box. Mine and a few others have had a similar problem as you. Mine turned out to be a bunch of loose connections inside this box. One of the wires and it’s wire nut completely melted into. Luckily in mine nothing touched the box. There are solid house type wires connected to stranded wire with wire nuts. It’s difficult to get a solid connection with solid and stranded wire together in a wire nut. Don’t just check the wire nuts for tightness but remove each nut and check that all of the wires are actually in the nut. There could be a short inside this box so make sure that ALL power is off before even touching the metal box as a hot wire may be against the box. This may not be your specific problem but it’s an easy thing to check.

 

I had the same issue that Ken describes.  The connections in the junction box were loose and I had a couple of fried connectors in the fuse box.  I’d also check all those connections.  Mike

[geokeg]

I checked the wire nuts  and wires in the junction box.  All were secure and no evidence of heat damage.  It looked very professionally put together.

 

I have been in contact with Jason Essary at Oliver.  With the inverter totally isolated from external circuits, with exception of incoming DC, the GFI still opens when turning on the inverter.  Green light remains illuminated, 13.9 volts feeding the inverter, no red light and no fault codes.  The inverter thinks it is fine, the GFI does not.  I will talk to xantrex tech support tomorrow.  I am hoping I can just replace the GFI in the inverter.

[Overland]

Have you tried unhooking the chassis ground from the inverter?  If that stops the GFI from popping then it might confirm an internal ground/neutral issue like Steve suggested.

[geokeg]

No I have not.  I did think about it, but your suggestion really helps to nail it.  If the GFI trips with ground disconnected, bad GFI. If it does not trip, internal short to ground inside the inverter.  I will do this before calling tech support.

 

Thanks guys for your input!

 

George

[geokeg]

I talked to tech support at xantrex today.  He said GFCI failure as well.  He also said it was a time consuming task to try and change the GFCI if the local repair shop would even try it.  So, I ordered a new inverter and will have the old one to take a look at internally, carefully of course.

[topgun2]

The bad news is that it sounds as if you are not still under any kind of warranty.  The good news is that YOU can now be our internal GFCI Xantrex expert?

 

Bill

[Overland]

I ordered a new inverter and will have the old one to take a look at internally, carefully of course.

 

I think there's a capacitor in there that you'll want to short out, but that should be the only potentially dangerous thing.  If we don't hear back from you, I'll assume I'm wrong.

[geokeg]

Yep, thanks for the tip.  I will be quite interested in identfying and shorting out the capacitor early in the process.

 

My new inverter arrives tomorrow.  After I do the remove, replace, and functional check of the new one I will give an update.

 

George

[geokeg]

Installed the new inverter today.  All operations are normal again with inverter output to microwave and AC outlets.

 

Before unpowering the old inverter I put a test light in the GFCI outlet to test the inverter output.  Power looked good until the GFCI tripped.  Pretty expensive GFCI failure...  I will probably look into replacing the faulty GFCI when I have some spare time and get a little smarter on shorting out the internal capaciter without lighting myself up.

 

The End ??

[topgun2]

Geokeg -

 

Be very careful (at least until you short out that capacitor).  While recently working on a microwave oven I was "shocked" to find out that the capacitor in those contains upwards of 20,000 volts!  Don't go near there without discharging that thing first.

 

Bill

[geokeg]

Bill,

 

Thanks for the additional information.  I will heed your advice.

 

George

 

 

 

 

[SeaDawg]

Just curious. Did Xantrex offer a price to repair the old unit? Some folks here are not interested in working on potentially dangerous electronics.

Sherry

[geokeg]

No they did not.   They have designated service locations and the individual shops may not  have the capability or expertise to do the specific repair required.  I elected to go with a new unit with 2 year warranty over the hastle and expense of getting my inverter to a shop and back with  uncertain timing and results.