What rooms or loads require AFCI protection?

Question

Do I need AFCI for dedicated circuits like sump pumps, furnaces, microwave, refrigerator etc.

You may be thinking of GFCI. There are certain loads you don't want on those kinds of "protective" circuits, the apocryphal example being a fire pump. Our sprinkler system's diesel doesn't have any low-water, low-oil or overheat shutoff safety systems, we want the engine saving the building at any cost - not tripping to save itself while the building burns down. — Harper - Reinstate Monica, Mar 07 '18 at 05:31
@Harper he might be thinking AFCI (Arc Flash Circuit Interrupter) if memory serves me right homes built after 2010 I think are required to have them for household outlets but I don't think they are required on fixed circuits as there is no PLUG to arc when it is old. They are notorious for tripping on any kind of jitter - such as simply plugging in a vacuum cleaner in the outlet while its power switch is still in the 'on' position. — Ken, Mar 07 '18 at 05:57
@Ken AFCIs aren't to protect normal plug use, they're there to protect from wiring faults in the walls. *coughbackstabcough* Thus, an AFCI+receptacle combo device is nearly useless - it will detect arc faults in appliances, but that only matters on appliances run unattended *which would fail-deadly*, e.g. electric blankets. — Harper - Reinstate Monica, Mar 07 '18 at 15:10
Actually the original reason for AFCI'S was because of electric blanket fires. AFCI'S were originally only required in bedrooms. Since the original requirement they have expanded the reason for them. — Ed Beal, Mar 07 '18 at 15:20
Well you look at [the stats](https://www.nfpa.org/News-and-Research/Fire-statistics-and-reports/Fire-statistics/Fire-causes/Electrical-and-consumer-electronics/Electrical) for electrical fires: the vast majority start with shorts and arcing not prevented by circuit breakers.... the vast majority start the fire behind the drywall (where the wires are: wire coverings, house insulation, timber)..... so that paints a picture that says the **majority of electrical fires are from arcing inside the walls**. — Harper - Reinstate Monica, Mar 07 '18 at 15:48
@Harper My thinking on this might be wrong but I thought it originated out of the fact outlets would wear out - hardly anyone would replace them and so the outlet and the plug would arc on account of the loose or poor connection. Inside walls .. I suspect a picture mounting screw hit the wires.. which is where the protective plating came in .. However the 2017 code exists and declares everything 120V. BTW: I wonder if those 220V Cheaters trip these like crazy :-) . Both you and Ed might be right though. — Ken, Mar 08 '18 at 23:59

ThreePhaseEel · Answer 1 · 2019-03-12T03:44:20.353

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Yes, you need AFCI protection

As of the 2017 NEC, AFCI protection has been extended to all 15 and 20A, 120V branch circuit outlets in all dwelling unit locations. This includes dedicated appliances such as furnaces and dishwashers, and even smoke detector circuits. The only exception present is for a fire alarm control panel for a protected-premises fire alarm system (i.e. with separate detectors, "brain box"/fire alarm control panel, and sounders) under NFPA 72.

edited Mar 12 '19 at 03:44

answered Apr 17 '18 at 04:21

ThreePhaseEel

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To clarify, does dwelling areas include unfurnished basements? – mreff555 Feb 11 '20 at 16:17
@mreff555 -- not in 2017, but AIUI, it's included in 2020? – ThreePhaseEel Feb 11 '20 at 23:40
For smaller appliances on dedicated “receptacle terminated” circuits, such as a 1/2 hp garbage disposal, could you get around this with a 10A breaker? – mreff555 Feb 12 '20 at 22:01
@mreff555 -- a 10A breaker would be too small for a 1/2 HP, 115VAC motor – ThreePhaseEel Feb 12 '20 at 23:25
The spec calls out an average load of 6.3A. Would peak power be that much higher? – mreff555 Feb 12 '20 at 23:35
@mreff555 -- you need to use the 9.8A figure given in Table 430.248 for a 1/2HP, 115VAC motor instead – ThreePhaseEel Feb 12 '20 at 23:57
Hmmm. Well that is an estimation of full load current. Still under 10A but I guess it would probably trip every time they shoved a pineapple in it. The other option is a 1/3hp motor I guess. – mreff555 Feb 13 '20 at 00:16

score 0 · Answer 2 · answered Mar 07 '18 at 06:27

Depending on where your sump pump is located and its voltage it might be exempt.

All 120-volt,single-phase, 15- and 20-ampere branch circuits supplying outlets or devices ... require AFCI protection.

There are some key words here '120 VOLT' and 'Devices' ...

If your furnace is 220 Volt you are good.

Your Refrigerator and Microwave on the other hand AFCI.

2017 National Electrical Code (NEC) article 210.12(A) requires Arc-Fault Circuit Interrupter (AFCI) protection for branch circuits supplying all 120-volt, 15 & 20 amp outlets or devices it covers the whole house ..

NEC 2014 had added the Kitchen and the Laundry rooms; NEC 2017 advanced it to whole house..

One big keyword device's - that includes Lighting .. anything connected to your service panel 120V in any room of the home. Although there is an exception for Panel to Subpanel where the first panel is being used as a junction box.

score 0 · Answer 3 · answered Dec 10 '18 at 19:38

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The one exception is the dedicated Bathroom circuit provided it has no outlets outside the bathroom it does not require AFCI protection. It is not mentioned in 2014 NEC 210.12 are being required to have AFCI protection.

answered Dec 10 '18 at 19:38

wexcellent

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This changed as of 2017 -- the exclusion you describe no longer exists. – ThreePhaseEel Dec 10 '18 at 23:58

score 0 · Answer 4 · answered Mar 23 '19 at 16:00

Unless you're in Michigan. Because of the downsides and cost of AFCI's

One of the more significant Michigan amendments in the MRC section E3902.11 which specifies arc-fault protection in 1&2 family dwellings. The 2009 MRC keeps the requirement for arc- fault protection the same as it was in the 2006 MRC.

AFCI tradeoffs are controversial. AFCI's use energy all the time, so called "vampire power". They false trip. In a sump pump application that false trip can lead to flooding.

And, they may or may not actually do the job intended: https://www.mikeholt.com/mojonewsarchive/AFCI-HTML/HTML/AFCI_-_Why_I_Have_a_Problem_With_It~20020801.htm http://www.combinationafci.com/resources/doc_ieee_combination_afci.pdf

score 0 · Answer 5 · answered Apr 19 '23 at 23:10

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Eaton publishes a very clear summary table for the requirements under 2008 through 2020 code cycles. I'm reproducing it here since this appears to be a popular reference question.

answered Apr 19 '23 at 23:10

KMJ

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What rooms or loads require AFCI protection?

5 Answers5

Yes, you need AFCI protection

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