Circuit breaker questions

[Blumlein 88]

There is an opinion out there that CPSC and NFPA were lobbied to amend NEC with AFCI requirements to create a market for it.

An opinion I share. However, I may have been influenced by industrial electricians who don't trust regular old circuit breakers. They can and do fail to work as well as fail to protect sometimes when they get a few years age on them. Such people will only have a genuine fuse box in their home. Fuses work. Breakers, GFCI, now AFCI, all too complicated and simply to create work when they act weird since most electrical stuff is dead reliable if not abused.

Certainly never heard about or saw any gear using AFCI until it became a requirement.

 

[gvl]

I don't know how how realistic, or well, how often occurring, are the parallel arc fault conditions in real life. I've seen glowing series arcs or rather overheating connections, but I don't think AFCIs are designed or can reliably to detect them.

 

[Blumlein 88]

I don't know how how realistic, or well, how often occurring, are the parallel arc fault conditions in real life. I've seen glowing series arcs or rather overheating connections, but I don't think AFCIs are designed or can reliably to detect them.

The 2nd gen afci breakers will detect both series and parallel arcing.

http://combinationafci.com/resources/doc_ieee_combination_afci.pdf

What AFCI breakers will and won't do at the link above.

 

[gvl]

The 2nd gen afci breakers will supposedly detect both series and parallel. 5 ma or so for parallel and 30-50 ma arcs in series.

I guess there is progress after all. It would be interesting to read a real world study on effectiveness of these devices.