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

  • What edition of the NEC does your AHJ use? Mar 7, 2018 at 3:08
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    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. Mar 7, 2018 at 5:31
  • @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 7, 2018 at 5:57
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    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 7, 2018 at 15:20
  • 1
    Well you look at the stats 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. Mar 7, 2018 at 15:48

4 Answers 4


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.

  • To clarify, does dwelling areas include unfurnished basements?
    – mreff555
    Feb 11, 2020 at 16:17
  • @mreff555 -- not in 2017, but AIUI, it's included in 2020? Feb 11, 2020 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, 2020 at 22:01
  • @mreff555 -- a 10A breaker would be too small for a 1/2 HP, 115VAC motor Feb 12, 2020 at 23:25
  • The spec calls out an average load of 6.3A. Would peak power be that much higher?
    – mreff555
    Feb 12, 2020 at 23:35

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.


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.

  • 1
    This changed as of 2017 -- the exclusion you describe no longer exists. Dec 10, 2018 at 23:58

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

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