Garage GFCI problem

[c4cruiser]

I have one circuit in my garage that has a GFCI receptacle (first receptacle on the circuit). For the last three nights in a row, the thing has tripped, but does so only at night!

The circuit is fed by a 20A breaker and I have a freezer, a refrigerator, a low-voltage lighting transformer, and a timer for a sprinkler system connected to the outlets. The GFCI receptacle also has a small transformer plugged in that is for some sort of booster for my Comcast cable.

During the day, everything works fine. I can manually turn on the low-voltage lights, the freezer and fridge work fine (the fridge is my kegerator setup so this is a very serious issue .... ). I can also plug in other items to any of the receptacles on the circuit and there's no problem. But at some time at night the !@^&*@^ thing trips.

Last night, I unplugged the low-voltage transformer thinking that it being outside may be a problem. But this morning, the GFCI was tripped.

I have read that GFCI receptacles wear out over time. This particular one is original to the house (22 years old) and it's the first time I have seen a problem. I could replace it, but if there is a problem with something on that circuit a new GFCI may not be the answer.

Ideas?

 

[Zeke]

That thing is so old that the box it came in said GFI, not GFCI.

 

[EOC_Jason]

A new plug is cheap, give it a try first. Only other thing I could think of is if there is moisture building up at night maybe and causing a short?

 

[Mustang51js]

You didn't mention anything about the sprinkler system, did you unplug the timer for that. Do you know what time it does trip. Is there anything outside on same circuit, say sprinkler turns on and gets outlet outside wet,ect

 

[c4cruiser]

You didn't mention anything about the sprinkler system, did you unplug the timer for that. Do you know what time it does trip. Is there anything outside on same circuit, say sprinkler turns on and gets outlet outside wet,ect

Right now the sprinkler water supply is turned off and the timer is off. So the timer should not be working at least in terms of operating the system. The timer has a digital time display, but there's no battery backup so once power goes out, the timer loses the wall clock time and displays some random value sort of like the old VCR's displaying the flashing "12:00".

The transformer for the timer is plugged into an outlet on the warm wall in the garage and the timer is also inside the garage. I can disconnect the transformer tonight to see if that makes a difference.

 

[mrjaw14]

I'd start disconnecting loads from the circuit and see if that makes a difference. You can also take a multimeter and look for current draws in places where there shouldn't be, like if part of the circuit feeds something outside the garage like a sprinkler, maybe the conduit is full of water and is causing a short causing the GFCI to trip. Might activate the sprinkler during the day and watch the current draw and see if as the ground gets wetter the current draw gets higher.

If the garage is unconditioned, it's possible the internal workings have some corrosion from the humidity (this would also manifest itself at night when the moisture condenses out of the air in the form of dew) and the GFCI is just too old to handle it and needs to be replaced. If you've removed all loads from the outlet and it still trips, then replace it. Might look at putting the new one in a weather resistant box with the foam gasket the weather resistant covers come with. I know the garage isn't moist, but it's still likely exposed to the elements with regard to temp changes, which can cause condensation.

 

[zmaxmotorsports]

Do you have a squirrel or mouse in there working the night shift?

 

[theoldwizard1]

I seem to recall reading somewhere that refrigerators and freezers were the EXCEPTION to GFCI outlet rule in garages.

 

[c4cruiser]

Do you have a squirrel or mouse in there working the night shift?

No, but if I catch one trying to pour a beer, there will be trouble....

The interior walls are hole-free as are the exterior walls and the bottom garage doors seals. There are only 3 outlets on this circuit, the GFCI and one outlet are on the same exterior wall and the 3rd is on the warm wall. All of the wiring in the walls goes thru the top plate and over to an outlet box then down. Nothing goes horizontally across the studs.

 

[pattenp]

There's no exception in the NEC that I'm aware of for 120V outlets in a garage not to be GFCI protected.

I seem to recall reading somewhere that refrigerators and freezers were the EXCEPTION to GFCI outlet rule in garages.

 

[Zeke]

There's no exception in the NEC that I'm aware of for 120V outlets in a garage not to be GFCI protected.

Probably not anymore but I seem to recall that a single plug outlet located behind a stationary object such as a fridge was OK. Moot point because the freidge and freezer are obviously coming on during the day.

It would not likely be the sprinkler timer as any draw on the transformer is static at this point.

I once had a wire that touched making a circuit when the conditions were warm and would disconnect during a cold period. It was inside a wire nut and I had a hard time finding it.

 

[Mustang51js]

I seem to recall reading somewhere that refrigerators and freezers were the EXCEPTION to GFCI outlet rule in garages.

The inspector let it slide because you could read it as inaccessible and to many people complaining that they lost all there food because gfi tripped over night. 2014 code will make it so you must have a gfi on it,whether it's behind fridge or off to the side. But that's also if it's adopted in your town

 

[sourdough]

I seem to recall reading somewhere that refrigerators and freezers were the EXCEPTION to GFCI outlet rule in garages.

Somewhere on this forum, a few months back, someone wrote that a freezer/refrig would trip a GFCI receptacle.

I have had a 14 cu ft chest freezer on a GFCI recept in my garage for over a year and no problems so far.

 

[EOC_Jason]

Maybe when it goes into defrost cycle at night?

 

[Nowater]

GFCIs are great, just not for freezers. Try replacing your old unit with a new one. The last ones I bought were 3 for about $30. Might be worth it to put each separate load on its own GFCI so only one load goes down at a time.

All of my outside outlets have their own GFCI so if something trips the circuit, I know where the device is that needs to be reset (so does my wife.) It is a small price to pay (the cost of an extra GFCI) for convenience.

 

[Norcal]

I seem to recall reading somewhere that refrigerators and freezers were the EXCEPTION to GFCI outlet rule in garages.

There used to be exception for fixed appliances, but the exception is no more.


If a refrigerator or freezer is causing a GFCI to trip, you have a defective appliance that needs to be repaired or replaced, it is not the fault of the GFCI.

 

[Stevie-Ray]

All of my outside outlets have their own GFCI.

That's code here.

 

[sourdough]

Maybe when it goes into defrost cycle at night?

If you are addressing me, this is a Sears chest freezer manual defrost.

 

[wyliesdiesels]

Somewhere on this forum, a few months back, someone wrote that a freezer/refrig would trip a GFCI receptacle.

I have had a 14 cu ft chest freezer on a GFCI recept in my garage for over a year and no problems so far.

There used to be exception for fixed appliances, but the exception is no more.


If a refrigerator or freezer is causing a GFCI to trip, you have a defective appliance that needs to be repaired or replaced, it is not the fault of the GFCI.

Fridges and freezers that trip GFCIs usually have a broken defrost bulb that when turned on, shorts to the base and causes the GFCI to trip

 

[c4cruiser]

Defrost "bulb"??

I put a timer on the circuit yesterday and it showed the GFCI tripped around 3:00AM this morning.

I've been looking at various refrigerator parts like a defrost sensor and defrost timer, but I don't understand why the GFCI trips when it does; it only seems to trip at some early hour. The fridge runs fine all day long and is working at least up until 10:30 to 11:00PM when I check it before retiring. Early the next morning around 6:00AM, I'll see that it has tripped and reset it.

 

[pullit]

GFCI sense a difference in the 2 conductors and trip. Hermetically sealed compressors have a large inrush current draw and can sometimes cause a GFCI trip. It could be that one of the compressors is starting while the other one is already running causing the voltage in the circuit to drop and the amp load to increase causing the GFCI to see the imbalance and trip. I would start with replacing the GFCI or try putting the 2 units on separate circuits.

 

[Alchymist]

GFCI sense a difference in the 2 conductors and trip. Hermetically sealed compressors have a large inrush current draw and can sometimes cause a GFCI trip. It could be that one of the compressors is starting while the other one is already running causing the voltage in the circuit to drop and the amp load to increase causing the GFCI to see the imbalance and trip. I would start with replacing the GFCI or try putting the 2 units on separate circuits.

Inrush current will not cause a GFCI to trip. There must be a difference in the hot and neutral currents to cause a GFCI to trip. Only way this can happen is if something creates an alternate path from the hot conductor to ground.

The problem with older refrigerators and freezers was that the motor windings were immersed in the freon inside the compressor. Any leakage in the motor windings coupled with any moisture in the system caused current leakage from motor windings to compressor case.

 

[wyliesdiesels]

GFCI sense a difference in the 2 conductors and trip. Hermetically sealed compressors have a large inrush current draw and can sometimes cause a GFCI trip. It could be that one of the compressors is starting while the other one is already running causing the voltage in the circuit to drop and the amp load to increase causing the GFCI to see the imbalance and trip. I would start with replacing the GFCI or try putting the 2 units on separate circuits.

I hate to break it to u but GFCIs dont care about overloads, under-voltage, over-voltage, etc. they only care about an imbalance of current between the hot and neutral! And how does an increase in current equate to an imbalance between hot and neutral??

 

[justsam]

And how does an increase in current equate to an imbalance between hot and neutral??

We may need to ask Congress to repeal Kirchhoff's Current Law!

It is unfair to wandering milliamps, and electrons that don't want to return to the source!

 

[Alchymist]

Perhaps pullit was pulling our leg?

 

[Alchymist]

We may need to ask Congress to repeal Kirchhoff's Current Law!

It is unfair to wandering milliamps, and electrons that don't want to return to the source!

It's only the queer electrons that run around blowing fuses and GFCIs.

 

[wyliesdiesels]

Lmao

 

[TheEquineFencer]

It's only the queer electrons that run around blowing fuses and GFCIs.

Alchymist, I think the technical electrical term is "Homotrons"

 

[Eriehunter]

Homotrons, that's funny.

I hate to break it to u but GFCIs dont care about overloads...........

In my experience a severely overloaded GFCI will trip before the breaker it is connected to.

 

[Alchymist]

Alchymist, I think the technical electrical term is "Homotrons"

Electrophobia - fear of homotrons.

 

[wyliesdiesels]

Homotrons, that's funny.




In my experience a severely overloaded GFCI will trip before the breaker it is connected to.

There is no circuitry in a GFCI that senses overcurrent!

 

[James-W]

I wonder if the problem ever got resolved. Hopefully he will return and let us know.