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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?

PhilPDX
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  • Just some background: I'm a homeowner, getting some electrical work done and doing some of it myself. I understand the whys for the GFCI requirements in the NEC, but some of the AFCI requirements have me scratching my head - in particular, the refrigerator requirement. I certainly _like_ the idea of AFCI protection, but my sense is that electricians haven't come to consensus that the benefits outweigh the cost (in terms of price and hassle). I'm willing to give AFCI's a shot, but... on a refrigerator? Hm. – PhilPDX Jan 03 '17 at 19:11
  • Where is your lication? I see PDX and think Portland Oregon, if that is the case no GFCI or AFCI is required behind things like refrigerators odbc table 1E , GFCI'S Deffinately have problems with fridges and some of the new fridges don't do well with AFCI'S – Ed Beal Nov 13 '17 at 23:02

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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.

Harper - Reinstate Monica
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    Your Code cite is a swing and a miss -- 210.12(A) is the correct section, and kitchens are a new addition to it in the 2014 NEC. Also, the only AFCIs I know of to have dropped the GFPE (30mA ground fault trip) function are the latest gen GE ones (the Eaton, Square-D, and Siemens designs still all do it) – ThreePhaseEel Jan 03 '17 at 12:47
  • I can dig up some stuff from an Eaton engineer later that argues that the GFPE requirement is actually *superior* fire protection to the "series arc" tests UL came up with – ThreePhaseEel Jan 03 '17 at 12:49
  • Can you point to the code section that "*suspend(s) GFCI requirements in locations where everything else must be GFCI, such as a garage or basement.*"? – Tester101 Jan 03 '17 at 15:22
  • ***210.12 Arc-Fault Circuit-Interrupter Protection. (A) Dwelling Units.** All 120-volt, single-phase, 15- and 20-ampere branch circuits supplying outlets or devices installed in dwelling unit kitchens... shall be protected by any of the means described in 210.12(A)(1) through (6):* AFCI protection is required for a refrigerator. – Tester101 Jan 03 '17 at 15:31
  • *I had it, Tester. I had it in my hand...* Nope, both my Google-Fu and my browser history is letting me down. I cannot find the reference for my 210.12 claim. Further digging DID reveal my claim of specific exemption for fridges in garages/basements was removed in 2008. So it appears I need to check dates a lot more closely, and capture links. – Harper - Reinstate Monica Jan 03 '17 at 18:55
  • The guy from Eaton (who just so happens to be one of the coinventors of the original Branch/Feeder AFCI setup) makes his case in [this conference paper](http://combinationafci.com/resources/doc_ieee_combination_afci.pdf) BTW. – ThreePhaseEel Jan 03 '17 at 23:08
  • @Tester101 -- it's actually not the case (the reason fridges in kitchens don't require GFCI protection is because only kitchen receptacles that serve "kitchen countertop surfaces", as well as kitchen dishwasher outlets, require GFCI protection in a dwelling unit. (Outside dwelling units, *all* kitchen receptacle outlets, including a receptacle dedicated to the fridge, must be GFCI protected.) – ThreePhaseEel Jan 03 '17 at 23:12
  • @Tester101 -- I was responding to your comment above that refers to finding a Code section that "suspend(s) GFCI requirements in locations where everything else must be GFCI..." – ThreePhaseEel Jan 04 '17 at 12:39
  • @ThreePhaseEel In that case, I'm not talking about kitchens. I'm talking about unfinished basements and garages, where GFCI is required in *all* receptacles. – Tester101 Jan 04 '17 at 13:43
  • @Tester101 -- there is no such Code clause as far as I know, then – ThreePhaseEel Jan 04 '17 at 23:17
  • I think I got that out of an curated article on I believe ECMweb that I took at face value. But it can't be as simple as "GFCI everything always". what about medical equipment (camper using CPAP) or any other situation where a nuisance trip is more hazardous than a ground fault? – Harper - Reinstate Monica Jan 04 '17 at 23:23
  • @Harper There are always exceptions to every rule, however, those are made on a case by case basis by the AHJ. If the circuit is specifically for medical equipment, I'm sure exceptions can be made. Unfortunately, there's no way for an electrician (or inspector) to know what's going to be plugged into the general purpose receptacle branch circuit. – Tester101 Jan 05 '17 at 15:56
  • I remember reading that hospital grade wiring typically has redundant ground paths and/or isolated grounds (symbolized by orange receptacles). Typical residential codes are often irrelevant when an engineer is stamping drawings/designs that are custom solutions for a specialty situation. – William S. Mar 08 '17 at 21:44
  • @cathode Interesting - I've never looked it up, but I thought the hospital orange receptacles were to indicate which outlets had automatic backup generator power. – manassehkatz-Moving 2 Codidact Apr 19 '18 at 19:32
  • Cathode is correct orange is isolated ground, red is usually e-power. – Ed Beal Nov 14 '18 at 22:09
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Building and electrical codes are developed by a group of individuals who sit around a table and push their ideas based mostly on the needs of developers and the material suppliers. These individuals are not always the brightest crayons in the box and go along with the flow. Codes often change based on economic needs and vary from state to state and country to country. Use common sense.

George
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