GFCI at Storage keeps tripping

[Keith55]

I plug my rig in (inside by itself) with everything off except the battery charger and fridge.

Without using an extension cord I plug the rig into a 15 amp (maybe 20) GFCI and watch everything work for 10 minutes.

The fridge is working. The batts are charging.

The next day I come back and the GFCI is tripped. No rain made its way in.

I hit reset and everything is back to working.

Any ideas? Is a criminal breaking in and hitting "Test" on the GFCI??



Thanks!!

[Krbjmpr]

It is likely the heating element on the fridge that is the culprit. Won't happen right away (after 10 minutes) is the big clue. As element heats up, it expands slightly, an internal defect is connecting neutral to ground. And since this is downstream of gfci, this is also the very scenario that many Gucci look for. Voltage on ground. The other method, btw, is loss of current balance between hot and neutral.


How to tell for sure?
Switch fridge to gas. If element is at fault, then running on propane will not energize the event and gfci holds.



Turn off breaker to your converter / battery charger. If not energized, can't leak


If you still have gfci tripping, unplug 120vac cord behind it and repeat. Now the fridge is isolated from gfci.


If you are *still* tripping gfci, then unplug charger. Same reason as above.


And IF STILL tripping, then leakage between neutral and ground are occuring somewhere else. Note I said neutral and ground, not device turned on and leaking to ground since everything is turned off.


AND IF YOU ARE STILL TRIPPING then there are other issues at play. Simplest is worn out GFCI. Most dangerous is a hot skin.

[keymastr]

With refrigerators being the most common cause of RV fires I would not keep it running in storage.

[twinboat]

Originally Posted by keymastr

With refrigerators being the most common cause of RV fires I would not keep it running in storage.

Wondering, are the fires more common on gas or electric.

[aether_one]

Originally Posted by keymastr

With refrigerators being the most common cause of RV fires I would not keep it running in storage.

Except they're not. Engine fires are the most common cause of RV fires. Another Interweb rumor squashed.

[twinboat]

Originally Posted by tfryman

Except they're not. Engine fires are the most common cause of RV fires. Another Interweb rumor squashed.

Oh, darn.

[Keith55]

Originally Posted by Krbjmpr

It is likely the heating element on the fridge that is the culprit. Won't happen right away (after 10 minutes) is the big clue. As element heats up, it expands slightly, an internal defect is connecting neutral to ground. And since this is downstream of gfci, this is also the very scenario that many Gucci look for. Voltage on ground. The other method, btw, is loss of current balance between hot and neutral.


How to tell for sure?
Switch fridge to gas. If element is at fault, then running on propane will not energize the event and gfci holds.



Turn off breaker to your converter / battery charger. If not energized, can't leak


If you still have gfci tripping, unplug 120vac cord behind it and repeat. Now the fridge is isolated from gfci.


If you are *still* tripping gfci, then unplug charger. Same reason as above.


And IF STILL tripping, then leakage between neutral and ground are occuring somewhere else. Note I said neutral and ground, not device turned on and leaking to ground since everything is turned off.


AND IF YOU ARE STILL TRIPPING then there are other issues at play. Simplest is worn out GFCI. Most dangerous is a hot skin.

Thank you - Lots to chew on here.

It is a residential refrigerator so I feel comfortable leaving it run in storage.

Interestingly, I went in this morning and turned off everything at the breaker except the refer. It wouldn't run. I turned the inverter on and it turned right on.

I'll see in a few hours if it kept running.

It is a new storage facility - literally just finished a few months ago so the GFCI is new. I'll take a tester over and see if it was wired correctly.

[Gary RVRoamer]

Originally Posted by Keith55

Thank you - Lots to chew on here.

It is a residential refrigerator so I feel comfortable leaving it run in storage.

Interestingly, I went in this morning and turned off everything at the breaker except the refer. It wouldn't run. I turned the inverter on and it turned right on.

I'll see in a few hours if it kept running.

It is a new storage facility - literally just finished a few months ago so the GFCI is new. I'll take a tester over and see if it was wired correctly.

Nothing unusual about the inverter. A residential fridge is wired thru the inverter to provide power when off-grid. If you turned off the breaker that feeds the inverter/charger, it no longer has any external power to pass through to the fridge. If the invert function is also turned off, no power to fridge.

[Persistent]

Good suggestions posted above. Heating elements often cause ground faults.

GFI's generally do not measure current to ground. If fact they may be installed on circuits that do not have a ground.

Disconnecting things to locate a ground fault requires disconnecting both the hot and neutral wire. Unplugging things works well.

Circuit breakers only disconnect the hot. Neutral stays connected. Wall or other switches do the same. Neutral must be disconnected as well to troubleshoot such circuits.

The ground fault may be in a circuit that is "turned off". It will still trip the GFI.

I wish you good luck and happy trails ahead!

[Ray,IN]

Krbjmpr
The internal heaters that reduce condensation are 12V, it makes no difference if the fridge is running on 120VAC or LP.

[richard5933]

Just takes one crossed wire to trip a GFCI outlet. Went for three years in our coach before we realized a 120v exhaust fan was wired wrong - found out when it tripped the first GFCI we plugged into. It was connected with a hot and ground - no neutral.

Have you plugged an outlet tester into the outlets you have on to see if there are any problems?

[Krbjmpr]

Originally Posted by Ray,IN

Krbjmpr
The internal heaters that reduce condensation are 12V, it makes no difference if the fridge is running on 120VAC or LP.

You are correct, an RV fridge door heaters are 12v. These won't cause a Gucci to trip however. But they will blow fuses, and occasionally will act as a fuse and open up before the fuse blows.


OP has stated that his fridge is a residential unit. So it's heaters, particularly with through door ice / water, will be 120vac.

[Krbjmpr]

Originally Posted by Persistent

Good suggestions posted above. Heating elements often cause ground faults.

GFI's generally do not measure current to ground. If fact they may be installed on circuits that do not have a ground.

Disconnecting things to locate a ground fault requires disconnecting both the hot and neutral wire. Unplugging things works well.

Circuit breakers only disconnect the hot. Neutral stays connected. Wall or other switches do the same. Neutral must be disconnected as well to troubleshoot such circuits.

The ground fault may be in a circuit that is "turned off". It will still trip the GFI.

I wish you good luck and happy trails ahead!

The 'groundless" gfic measure current balance between hot and neutral. When a imbalance occurs, indicating a fault, relay / solenoid is disengaged.



Most of the wall units I have had the displeasure of working with monitor circuit balance and presence of fault on ground. I now have trouble with using isolation transformers faulting a gfci, despite being a maintained 10Mohm and higher isolation to ground.


You seen the assemblies that have ground connections for upstream and downstream on different screws yet? I suspect those are device specific, and monitor for integrity of ground circuit downstream and upstream independently in addition to monitoring the neutral / ground loop (if it exists).