Have not heard of anything. You have a link or something with a recall on breakers???
Here is the info for a recall of the sq. d panels
Increased neutral current is only possible with multi-wire 3 or 4 wire circuits. It would not occur on 2 wire branches typically seen in residental construction using AFCI breakers.
So I have checked connections. Everything is tight and up to par. Could this have been a bad batch of breakers??? Because I have 9- single 20 and 8 single 15. No signs of anything wrong on the wire, just the insulation has changed color. They are all plug on breakers. These were installed in 2018. Their square d homline.
I think I've read twice where you said this
I asked at a IAEI class about concerns on AFCI breakers in a 42 circuits normal 14.5" wide panels overheating especially if panel was installed between wall studs and had over 30 AFCI breakers. Was told that UL performed test on 84 circuit panels with entire panel filled with AFCI breakers and that they did not produce any overheating. Can tell you that at the large hospital that I retired from we used a FLIR camera once a year to check all of the thousands of circuit breakers. We had a mental health unit where we had over 30 Square D bolt on 20 amp AFCI circuit breakers. Both these and GFCI breakers usually were a few degrees hotter then a regular circuit breaker. Never saw a wire discolor on any of them. I would cut at least a inch off of discolored wire then reinstall using a torque driver then check back in it several times.
Doesn't all of the load neutral current flow through the breaker? The breaker is plugged into the neutral bus and the branch circuit neutral connects to the terminal on the breaker.
Is it monitored in any way other than imbalance? Maybe not even that on some.
Most of them are like this but some newer types don't have a neutral terminal on the breaker. The neutral lands on the neutral bar like on a traditional breaker. Only AFCI types can be like this, not GFCI types (obviously, I guess).
Yeah, sort of. There are two kinds of AFCI detection, Series and Parallel. Most of the AFCI-only breakers are Series, meaning they monitor only for wire breaks on the hot line, so the neutral connection is just to power the PCB inside. Parallel type only monitor for arcs from line to neutral or line to ground, so they do monitor the neutral current, but most AFCI-only breakers are not Parallel type since that doesn’t detect wire breaks, which was the original problem.
I don't believe the above is correct, as far as which types of breakers detect current imbalance between line and neutral. IIRC many (all?) of the earlier Branch Feeder (Parallel only) AFCIs did check for current imbalance. And to my knowledge, almost all the AFCIs available today are Combination type, while several manufacturers of them no longer check for current imbalance.
However a GFCI or dual function breaker, will not work unless the circuit neutral current passes through the breaker. That means twice the heat generation at the bus connections and the screw lugs. If all are good, there will be no significant heat compared to the thermal element inside the breaker. But it gives twice the opportunity for a heat-producing bad connection.