Residential Fridge - magnum inverter GFI tripping

rpotter

Active Member
We are having a horrible time with the residential fridge and the inverter in our 2015 Bighorn 3570RS. The first issue was noticed immediately when we got it home from the dealer. The GFI on the inverter would trip within a couple of minutes after disconnecting shore power and engaging the inverter. We contacted Heartland and they sent us a replacement (same model) that was suppose to have either a software upgrade or some other adjustment (it varies depending on who I talked to at heartland). We thought this fixed the problem. What we discovered was the fridge would stay on (lights only) for about 5 or 6 minutes and then the inverter GFI would trip. We suspect it trips as soon as the compressor kicks in. We expect it is again, another bad inverter. I'll explain why. We have no problem running the fridge when plugged into our 15amp outside GFI receptacle in our house. To test the inverter side of the transfer switch I disconnected the trailer power cord from our house and then plugged the transfer switch on the inverter side into a different 15amp GFI receptacle in our home and again the fridge ran without issue. The outside GFI's in our home are receptacle types similar to what is built into the inverter and they never once tripped when running the fridge from either side of the transfer switch. I then plugged a small portable heater into the inverter to test if it was a load issue and other than a load warning the GFI never tripped.
I watched the inverter DC power indicator right up to the point the GFI trips (5+ minutes after the fridge is connected) and it stayed around 12.9 volts. I did find a lot of refrigerator posts on sites saying they don't recommend them connected to a GFI for the same issue I am having (false GFI tripping). At this point I am at a loss. Very upset due to now having to cancel our trip to the east coast to see our daughter arrive back from a 6 month navel deployment. Huge fanfare and military ceremony when the ship docks. The trip has been planed for weeks and we had the trailer almost fully packed when we discovered the inverter issue. I have numerous campground bookings with many having cancelation fees. Wife is extremely disappointed and can't believe we have a 95k trailer we can't use. She was hoping I would pull a rabbit out of the hat but other than confirming its another bad inverter there was nothing I could do to fix the issue. Thus far since April we have used the trailer once to transfer stuff from our old trailer. Sadly, this was to be our maiden voyage.


Sent from my iPad using Tapatalk
 

danemayer

Well-known member
Hi rpotter,

Sounds like you've done a lot of diagnostic work on this problem.

Since you watched the voltage indicator on the inverter when the refrigerator's compressor started, and the voltage didn't drop, it sounds like you're not overloading the inverter or batteries. If there was a problem with the refrigerator drawing too much power, I think you'd see the voltage drop or an error code on the inverter. You didn't mention any inverter error codes, so I'm assuming there are none. I'm also assuming the symptoms were exactly the same on the first inverter; GFCI trip with no error codes.

That all leaves me thinking that perhaps there's a legitimate ground fault. You might pull your refrigerator away from the wall to inspect the plug and outlet, and any visible wiring. If in a slide, also check the 110V wiring as it's routed into the slide. Since it's easier to check the wires under the slide, I'd do that first.

Several people have reported problems with leaking ice maker water lines. If water's getting into the outlet for the refrigerator, that might be the problem.
 

rpotter

Active Member
The only thing with considering it may be a legal ground fault is that it only happens 5+ minutes after the fridge is connected which makes me think it is when the fridge compressor comes on and applies load. Secondly, I have plugged the inverter side of the transfer switch into two different house GFI receptacles and neither of them tripped. And you are correct there are no error codes generated on the inverter. I did notice though that the DC indicator on the inverter stayed around 12.9 volts but the AC indicator never showed above 0.00 which is odd since my amp meter showed an .8 to 1 amp draw on the fridge line right up till the GFI trips. When the inverter GFI trips after 5 minutes I don't show an increase in the amp draw which I assume is due to the GFI tripping so fast the meter doesn't get enough time to capture the increase in demand. My next test today is plugging the inverter side of the transfer switch into my home GFI receptacle and see what the amp draw is after the 5 minutes when it would normally trip the inverter GFI. If it increases at around 5 minutes it would confirm it is when the fridge demands more load. If that is the case the issue would be the combination of the fridge, compressor start up demand and the inverter GFI. Thanks for your input. Greatly appreciated.


Sent from my iPad using Tapatalk
 

justafordguy

Well-known member
Sure sounds like another bad inverter. Mine did the same thing we we fisrt got it. Heartland sent us a new one and it has worked great. You need to get them to send you another inverter or just go buy a 2000watt inverter (which would be better anyway).
 

wdk450

Well-known member
If nothing else works, you could spend the money on an 1:1 isolation transformer of the correct wattage to handle the refrigerator. This gives you a floating (non-ground referenced) AC supply to the refrigerator. The refrigerator electricity doesn't seek ground, it just seeks the other side of the circuit, like in a battery circuit. The electrical isolation provided by the transformer will normally keep the GFI from tripping.

BTW, did you change out the GFI controller outlet just for the heck of it? Sometimes these can do weird nuisance trips.
 

rpotter

Active Member
Well I managed to pull the rabbit out of my hat and we're going to make our trip after all. Heartland is shipping me another Magnum inverter but it won't arrive in time so I bought one from Canadian Tire (Eliminator - Canadian Tires own brand) pure sine wave - 1000 watt continuous with 2000 watt peak (same specks as Magnum). Had USB port and rj11 remote switch as well for $300.00. Hooked it up and fridge is running with no problems after 6 hours operation. The eliminators fan never even comes on and shows the fridge drawing between 140 to 150 watts.


Sent from my iPad using Tapatalk
 
Top