I changed the circuit breakers on my Square D QO panel for the heck of it (they were all getting old).
But now having worked with the panel safely, I was thinking about changing some of these breakers to AFCIs.
Assuming my QO AFCIs will fit in my QO panel, I have a few questions.
I know where they should be used (on all outlets in the bedroom) and at least two circumstances where they should not (with a shared neutral, or on cicruits larger than 20 Amps - I do not think they make them that big).
Are there any other cicruits where an AFCI should not be used? In the kitchen? For a sump pump? The furnace? On GFCI-protected receptacles? Lights? Or can they be used anywhere?
And do AFCIs incorporate some degree of GFCI protection? I know in theory, no, but on the instructions the AFCI stated that it did not meet GFCI protection in accordance with Section A (or something like that). Does that mean it provides some GFCI protection, but it is just not that good?
It will be interesting to see how my AFCIs hold up to my old AC wiring. My venture may be a complete waste of time. I am guessing only small imperfections are needed to generate a trip.
In Europe, scratched insulation can be enough to trip similar breakers there and their use is often impractical in older houses, even where the wiring is perfectly safe.
My next project will be to rewire the stove (without an AFCI, don’t worry). It took me ages to find 6-gauge wire with 3 conductors and a ground. And it cost a lot. Lowes did not stock it. But I have found some and will be moving over to a four-wire system. I am doing this to stay code-compliant, but why are four wires safer than three? Is it because of the small chance that the range develops a fault and the earth/neutral becomes disconnected from the panel?
The stove in my neighbor’s house appears to be wired with lamp wire. But that is another story.