smoke alarms on AFCI

[Jerry Lozier]

New House: Never seen smoke alarms tied into AFCI before:when I tripped AFCI to test, all smoke alarm indicator lights throughout house went off

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Still has battery backup....

Outside of probably not being best practice.... what say you??

[SNations]

I believe that NEC requires smoke alarms in bedrooms to be AFCI protected. Some jurisdictions give exceptions to this rule. Supposedly, there are reports of fires starting at smoke alarm wiring.

From 2009 IRC:

E3902.11 Arc-fault circuit-interrupter protection. All branch circuits that supply 120-volt, single-phase, 15- and 20-ampere outlets installed in family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreations rooms, closets, hallways and similar rooms or areas shall be protected by a combination type arc-fault circuit interrupter installed to provide protection of the branch circuit.

Exception:

1. xxxx

2. AFCI protection is not required for a branch circuit supplying only a fire alarm system where the branch circuit is wired with metal outlet and junction boxes and RMC, IMC, EMT or steel armored cable Type AC meeting the requirements of Section E3908.8.

I believe that exception 2 makes it clear that a smoke alarm must have AFCI protection if it's wired along with the rest of the bedroom. So your case may be different if your alarm is wired separately, but it's not the case where the smoke alarm is not allowed to be on AFCI.

[Chad Fabry]

From the 2008 NEC- NY adopted this as of 12/28/2010

It's important to remember that outlets and receptacles aren't synonyms.

210.12 Arc-Fault Circuit-Interrupter Protection.

(A) Definition: Arc-Fault Circuit Interrupter (AFCI). A device intended to provide protection from the effects of arc faults by recognizing characteristics unique to arcing and by functioning to de-energize the circuit when an arc fault is detected.

(B) Dwelling Units. All 120-volt, single phase, 15- and 20-ampere branch circuits supplying outlets installed in dwelling unit family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, or similar rooms or areas shall be protected by a listed arc-fault circuit interrupter, combination-type, installed to provide protection of the branch circuit.

[Jerry Lozier]

thanks guys

Don't know what I was thinking, yes local AHJ requires, does seem kinda ironic though??

[inspector57]

Not ironic at all to me. Arc fault is designed to stop the fire before it starts while the smoke detector merely alerts you to get out after the fact. Smoke alarms have battery backup so the lack of power to the alarm because of an electrical fault is a non-issue IMHO.

[Jim Port]

The exception would not apply as smoke alarms are not fire alarm systems.

Under the NEC the smokes are defined as outlets and require AFCI protection.