REFER+ GFI

[jacobsond]

I do low voltage work and appliance repair,but I have a GFI question.I have a customer with intermittent tripping of a GFI outlet that the refrigerator is plugged into.The appliance service guys say no no?to plugging a refer into a GFI because you can get intermittent triping.I dont think it would be easy identifying the part that would cause this without spending alot of $$$$.I believe the manufacturer also recommends no GFI.The outlet in question is above the countertop not behind the refer so I would think it would have to be a GFI outlet.What are your opinions? I think I should have him get a non GFI outlet installed behind the refer

 

[tom baker]

Re: REFER+ GFI

The NEC has specific requirements for where GFCI's are required, with some exceptions.
Its possible that a GFCI is not required, but what is the location and occupancy?

 

[bphgravity]

Re: REFER+ GFI

In order for the refrigerator to obtain its listing, it must pass a leakage current test not exceeding that which will trip a Class A gfci device. However, I agree a non-gfci protected receptacle for the refrigerator would be an acceptable alternative.

 

[charlie]

Re: REFER+ GFI

You might want to get used to GFCI problems since the exceptions to 210.8(A) are being removed (at least in the proposal stage). If you are interested in this subject, I would recommend a comment when the ROP comes out.

 

[ryan_618]

Re: REFER+ GFI

Charlie, do you know who the submitter for that was, just out of curiousity?

 

[Mike03a3]

Re: REFER+ GFI

Originally posted by charlie:
You might want to get used to GFCI problems since the exceptions to 210.8(A) are being removed (at least in the proposal stage). If you are interested in this subject, I would recommend a comment when the ROP comes out.

Did 210.8(A) change in 2005? Eliminating the exceptions (at least those in 2002) wouldn't prevent continuing to use a non-GFCI receptacle in a kitchen if it isn't serving a counter space (210.8(A)(6))
That doesn't help the OP's situation, since that refrigerator is using a countertop receptacle.

In his case, I'd verify that there's no wiring problems with the circuit in use first. If it really is the fridge, I'd consider another fridge or a separate circuit with a single receptacle behind the fridge.

 

[Matt Harp]

Re: REFER+ GFI

If the frig is on a GFCI PROTECTED receptacle along with anything else that would place a significant amperage draw, that could also do it. It has been my experience that a frig doesn't draw much power until the compressor kicks in...then it is a real power hog for a few seconds. I have seen 15 AMP GFCI receptacles on a 20 amp small appliance circuit that just will not take 15 amps. For a few extra bucks, you can get a GFCI rated at 20 amps that will still be in compliance and solve the problem. Best way I know to see if this is the problem is to identify the circuit in the panel, unplug the frig and take a reading. Then have someone plug the frig back in while the amp probe is still reading the circuit. Anything above about 14.5 amps might warrant the changeout of the GFCI. Bear in mind, there is probably another appliance on the circuit that is either running or starting up when the frig compressor kicks in.
All that said, I think the new circuit on a single receptacle is the best and most elegant solution.

 

[charlie]

Re: REFER+ GFI

Sorry Ryan, that is a panel 2 issue that we discussed in our meeting. Removing most of the exceptions don't bother me too much but the one for the OH garage doors really sticks in my craw.

 

[hurk27]

Re: REFER+ GFI

By Matt: I have seen 15 AMP GFCI receptacles on a 20 amp small appliance circuit that just will not take 15 amps.

Matt a GFCI receptacle has no over current protection in them at all.
They only provide current leakage detection between the hot and ground by monitoring the current on the hot and neutral. It will pass full current through the device even if it was connected to a 40 amp breaker. It is myth that they provide overcurrent protection they do not.

I have found that newer GFCI breakers or receptacles are less susceptible to inductive kick back that plagued earlier GFCI devices, they now have a delay and TVSS in them to help lower neusent tripping.

But I still wont put a frig or sump or ejector pump (in basement) on one.

For more info about how a GFCI works go "HERE"

 

[unimo]

if the GFI recep is right there where the fridge plugs in (not a regular recep on the load side of a GFI in another box), I would just replace the GFI recep with a single 20A U ground recep. (not duplex). So nothing else can be plugged in there, then it doesn't have to be a GFI.

 

[iwire]

Unimo you can not always replace a GFCI with a single receptacle for a specific appliance.

The only places you can currently do that are garages and basements.

And as has been mentioned it is likely that with the 2008 NEC the exceptions allowing that in basements and garages will be removed.

 

[don_resqcapt19]

Ryan,

Charlie, do you know who the submitter for that was, just out of curiousity?

I think it was a NEMA directed proposal.
Don

 

[don_resqcapt19]

Note that the original poster said that the receptacle that serves the refirgerator was above the countertop. All receptacles that serve the countertop must have GFCI protection, there are no options or exceptions.
Don

 

[unimo]

So if you tapped into the countertop box with a handy cover with a mc 90,and mounted a regular recep behind the refer you could do it, right? (Assuming there's enough other counter outlets.) wouldn't be pretty, but there's a permanent cord there anyway.
Of course, dropping a new one cut in behind the refer is better. Or quick and easy; get a brand of GFI that won't trip with the refer motor.

 

[George Stolz]

So if you tapped into the countertop box with a handy cover with a mc 90,and mounted a regular recep behind the refer you could do it, right? (Assuming there's enough other counter outlets.) wouldn't be pretty, but there's a permanent cord there anyway. Of course, dropping a new one cut in behind the refer is better.

Yes, legal. But depending on the type of construction and the limitations of it, I would opt for flexing through the cabinet out the side of the cabinet before flexing straight from the receptacle outlet.

Like you, ideally I would try to get the wiring fully concealed and cut-in a receptacle for the fridge.

Or quick and easy; get a brand of GFI that won't trip with the refer motor.

I would venture to say that it's generally the fridge's fault, and that any GFI is going to trip if that's the case. They all have to pass the same standards, and none will allow more than 6mA of ground current. Best bet is to keep the fridge off the GFCI entirely, until the NEC requires it, IMO.

 

[Mike03a3]

One thing that is often overlooked about GFCIs is that they have a trip curve, much like a circuit breaker. The higher the leakage current, the faster it must trip. At 5ma the UL standard allows something like 5 seconds, although most GFCIs actually respond much quicker. The other fact is that while the standard requires they trip at 5ma +/- 1ma eventually , they may allow much higher current in the meantime. Up to 110ma.

I have measured response times around 25ms from one brand and close to 150ms for another, with the variation between receptacles of a single brand being typically less than 5ms.

The point is, you may cure some false trips with motor loads by simply trying another brand.

 

[al hildenbrand]

Re: REFER+ GFI

. . .but the one for the OH garage doors really sticks in my craw.

I can see it now. The market for cord and plug connected isolation transformers is going to take off.