Electrical – AFCI breakers/protection and refrigerators – a bad idea

afcicircuit breakerelectricalgfci

The 2014 NEC requires AFCI protection for refrigerators. I've read that one shouldn't use GFCI protection for a refrigerator, but I know that AFCI breakers do include ground-fault protection (at a 30mA threshold, as opposed the 6mA threshold for GFCI breakers or AFCI/GFCI dual breakers).

Are nuisance trips a problem when using an AFCI breaker on an individual branch circuit for a refrigerator?

And if so, I'd be curious – are the nuisance trips typically due to false-positive ground faults (difference between line and neutral current – as a GFCI breaker would detect), or false-positive arc faults (series arcing or line-to-neutral arcing)? I believe most of the AFCI circuit breakers on the market will distinguish between those two, in order to help diagnose the wiring problem.

Some good info about GFCI and refrigerators here: Why is GFCI tripping on refrigerator circuit?

Best Answer

The question presumes something I do not believe.

I don't believe all AFCIs also do GFCI at 30ma level.

This answer here is a very well-informed and interesting exposition on how many AFCIs were given a "weak" GFCI function to detect arc faults to ground. But this was less than ideal - not least it requires you make a whole line of 2-pole AFCIs; in most of those applications, handle-tying two 1-pole AFCI would suffice if the AFCI didn't need to do that GFCI-ish thing.

This lesser protection was typically 30ma. Remember, 30ma protection is inadequate for kitchens, garages, basements or anywhere else NEC requires GFCIs.

Some people believe AFCIs are required everywhere GFCIs are not. The NEC does not say that. If your local inspector says so, you need to have the discussion with them. You can fight city hall, but it's cheaper to just replace that problematic fridge.

Refrigerators are not the use-case for AFCI or GFCI

GFCI is to protect people from shocks, typically from lightly insulated plastic gadgets getting broken or wet, or the user having contact with an energized part of a 2-prong tool. This is absolutely irrelevant to an immovable box with a steel chassis, all the 120VAC gear inaccessible at the bottom rear, and a fully plastic inner lining. It would be nigh impossible for a consumer to contact anything 120V if they were trying.

AFCI is to prevent fires from wiring faults either in house wiring or in plastic, flammable devices. Being entirely contained inside an all-steel box, it's nigh impossible for a wiring fault inside the fridge to start a fire without also pulling enough current to trip the breaker. Yes, the cord, receptacle or in-wall wiring could have a problem; but consider the same logic that is applied to the NEMA 10 receptacle: this is fixed equipment with a typically inaccessible receptacle, which is rarely unplugged or moved.

Sometimes, a ground fault trip is a ground fault

I do see a lot of forum posts like

My old fridge never tripped the GFCI before. Now suddenly it's tripping the GFCI a lot. Why do fridges need GFCI protection anyway? Can I remove the GFCI protection?"

Sometimes, a GFCI trip is exactly what it says on the tin -- "working as intended" genuine trip caused by faulty machinery. Often cleared by a good cleaning, but sometimes, you just need a new fridge. Insulation failure is one way machines fail.