[Rav]

We eventually want to have our old house wiring rewired (it's currently some sort of armored cable, some with bonding strips). But until then I thought it might be prudent to have AFCI protection installed.

I thought of adding an AFCI receptacle at the beginning of the run, but the problem is that the two circuits with most of the outlets on them (breakers 2 & 3) don't start with receptacles, but lampholders with pull cords and lights with toggle switches. I didn't think that installing an AFCI receptacle later in the run was a good idea since it wouldn't protect the previous outlets (lights).

So now I'm thinking the better solution would be to install an AFCI breaker in our panel. This isn't something I'm comfortable doing myself -- I'd hire an electrician.

I'd just like to get an idea whether this is feasible with our current panel. It was installed in 1985. The main breaker is rated 150 amps. The info I found on the panel is: QO Load Center Cover, Cat. No. QOC3OU, series G1, type 1 enclosure, Square D Company, stamped with number “F0605031.” Picture below. Thanks.

 

[Arrow3030]

30 years after it's been installed and still considered a top of the line load center. Yes, you can get arc faults for it.

 

[Jump-start]

Yup! Here are the breakers for that:

http://www.homedepot.com/p/Square-D-QO-15-Amp-Single-Pole-CAFCI-Circuit-Breaker-QO115CAFIC/202353327

 

[Rav]

OP here. Thanks for the answers so far, but I have a follow-up question. Although I don't know which cables exiting my panel are for which circuits, I discovered one point in the unfinished basement where one Romex cable seems to contain wires for both circuits 2 and 3, which are the circuits I'd like to add AFCI breakers to. I determined this by turning the breakers for those two circuits off, one at a time, and my non-contact tester continued to alarm until I turned off both circuits at the same time. It does seem to split off into two separate circuit cables after that point, though I'm not positive about that. At any rate, does this mean that this is a multi-wire branch circuit? And if so, does that mean that AFCI Breakers won't work on these circuits? Thanks.

 

[Luke M]

Singles wouldn't work in the case of multiwire, but a dual would.

 

[Rav]

Singles wouldn't work in the case of multiwire, but a dual would.

Do you mean dual as in a combined GFCI and combination AFCI breaker? Or some sort of double-size breaker that would handle both circuits? And is there such a breaker that would work in my particular panel (Square D, QO load center)? Thanks.

 

[Luke M]

Do you mean dual as in a combined GFCI and combination AFCI breaker? Or some sort of double-size breaker that would handle both circuits? And is there such a breaker that would work in my particular panel (Square D, QO load center)? Thanks.

The latter. I think squared makes one.

 

[Jim Port]

If you have a MWBC the breakers should be stacked so they were in slots 2 and 4 and have a handle tie or a double pole breaker.

 

[Rav]

If you have a MWBC the breakers should be stacked so they were in slots 2 and 4 and have a handle tie or a double pole breaker.

When I have an electrician come to look at it, if they determine that it is MWBC, since they're currently in slots 2 and 3 and not tied together (see pic in the first post in this thread), should he move them to different (stacked) slots at the same time that he changes the breakers to AFCI? (Or move 4 somewhere else and move 3 there.) There are some free slots at the bottom end of the panel.

 

[JonCiccarone]

When I have an electrician come to look at it, if they determine that it is MWBC, since they're currently in slots 2 and 3 and not tied together (see pic in the first post in this thread), should he move them to different (stacked) slots at the same time that he changes the breakers to AFCI? (Or move 4 somewhere else and move 3 there.) There are some free slots at the bottom end of the panel.

Yes, if possible, the simplest solution would be to swap the circuit breaker (and hot wire) in slot 4 with the circuit breaker (and hot wire) in slot 3, so that the MWBC is stacked. Then replace the now stacked circuit breakers 2 and 4(formerly 3) with a double-pole AFCI breaker that fits your load center, like this one:
http://m.homedepot.com/p/Square-D-Q...H=REC-_-irg_aic-3-_-202353327-_-204844653-_-N

Make sure to replace the circuit breakers with a double-pole breaker of the same amperage. I can't tell from your picture if breakers 2 and 3 are 15amp or 20amp. The link above is for a 15amp breaker, if the circuit breakers you are replacing are 20 amp, get the same double pole AFCI breaker in 20amps.

Hope this helps!
JC

 

[Rav]

That helps a lot, JC. Thanks.

 

[Rav]

OP here. If I understand my panel correctly, breakers 2 and 3 are on opposite phases. Assuming it's verified that circuits 2 and 3 are indeed a MWBC, if I have the breaker currently in slot 3 moved to slot 4 so it can be combined with breaker 2 into a double-pole AFCI breaker, are slots 2 and 4 also on opposite phases? I think that's the case but I want to be sure. Thanks.

 

[Jim Port]

The hot legs alternate ABAB from top to bottom. Breakers 1 and 2 are leg A, 3 and 4 are B, 5 and 6 are A.