2 poles AFCI for 240V use

[Mica]

Hi all,

We want to install 220v cables underneath the subfloor to heat the upstairs rooms. Since the subfloor is made of plywood, we want to use AFCIs to provide added security against fire. ( In a dedicated panel 5 X 20A = 100A ).

The only 2 poles AFCIs I could find were ridiculously priced at over 220$ for some refurbished and over 300$ for new ones?

I was wondering if I could use 2 single poles by connecting them in parallel (with both white neutrals connected to the neutral bar).

Nowhere is it written in the code that I have to install some AFCI for such a purpose but we want to be safe.

Any suggestions will be greatly appreciated,

Mike

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[jamesgangnc]

100amp afci's are expensive. Two singles will not save you enough to be worth the trouble.

[Wayne Whitney]

The only current manufacturer of two pole combination AFCIs is Siemens, their 20 amp 240V combo AFCI breaker is Q220AFC.

Nope, that's not going to work. Among other reasons, an AFCI includes

30ma (or so) ground fault protection, and so all the conductors of the circuit have to pass through a single breaker.

Cheers, Wayne

[John Grabowski]

*Save your money. An AFCI protects against arcs. You are most likely to have an arc at the point where the connections are made. There won't be any arcs in the cables under the floor unless you drive a nail or screw through them. You should also contact the manufacturer of the heaters to see if they recommend the AFCI's. They may tell you not to use them because the electrical characteristics of the heaters may cause them to trip.