AFCI breakers?

Do any of you find that the AFCI breakers are a little to sensitive. Or did I just see a bad batch of breakers. A lady told me that in her condo unit bedrooms if she plugs in a lamp and her computer she blows the AFCI breaker. And across the street I could not run a circular saw without tripping the breaker. Our electrician finished both units at the same time. the electrician did tell me they are sensitive but should they be that sensitive.

Sounds like/there are connections that are loose and the breaker is seeing the arcing. Does your saw trip every AFCI circuit or just one? Can the homeowner try the lamp and computer in another circuit? If so this would confirm the problem is in the wiring.

Both condos are 2 bedroom units and are the AFCI breakers and all four of the bedrooms breakers will trip when I use my saw in them. Either we have 4 bad AFCI breakers or like you said bad wiring which means the guy our electrician sent out for the wiring is making the mistake somewhere.

…or a bad saw! :neutral:

If the GFCI trips every time I get in the pool with the hair dryer, the universe is telling me something.

If your AFCIs trip every time… Yada yada yada… Listen to what the lamp and the saw are telling you!!

Sounds like the saw is the issue.

many mfr have this or similar
**When an AFCI trips, the cause of the trip must be determined before placing the circuit back into service. **

Any motor can trip an AFCI, vacuums do it all the time. Some motors inherently spark which is exactly when the AFCI is to trip. That is a reason why AFCIs are not put on appliance circuits.

prolly shouldn’t be needing the circular saw in the bedroom too often anyway…

Guess he doesn’t know how to handle ‘real’ wood! :wink:

Allow me to inject a bit of a dissent into this conversation…
Yes, a lamp should typically not trip an AFCI.
A vacuum might.
As others have noted, a circular saw would normally not be plugged into a circuit that is mandated to be protected by an AFCI, even by the 2014 NEC.

There are many variables.
GE AFCI’s are notoriously more sensitive than average, for instance.
If you have an additional source of line “noise”, such as a motor running on another circuit or a power line remote control system, such as X10, even a small spike on the line (e.g. a lamp being turned on) may put the breaker “over the edge” and make it trip.
I would start with the simple and the obvious, such as real arching from a lose connection or bad wiring. If everything looks OK, trying a different AFCI may be in order.
Classified CH/Eaton breakers fit in most panels, so replacing a “problematic” nuisance-tripping AFCI with a classified one may be the ticket.

I actually was not cutting in the bedroom I was on the front porch with the bedroom on the otherside of the wall it was a GFCI breaker outside and tied in with the bedroom. The GFCI was not tripping but it was shooting strait to the AFCI breaker and tripping that which it should but I am just saying that is what was happening. Then the lady across the street said to me her computer and her lamp was tripping her AFCI. Then I tested all the bedrooms with the saw of course not cutting anything so I did not make a mess and the breakers would trip.

Yep, anything with a motor can be tricky to run on a circuit with AFCI breakers. A few years ago when AFCI breakers became code for bdrms we had a customer that wanted to run a treadmill in a basement bdrm of their brand new house. They could not keep it running for more than a few seconds before tripping the AFCI 15A Cutler Hammer breaker. We tried switching it out thinking it was weak and got the same result w a new breaker. Only solution to make that particular machine run on that circuit was to slap in a regular 15A breaker.

Umm…Sadly I disagree with the majority of this statement (not being negative to you my friend, just do not agree based on my extensive experience with AFCI’s) as it is needless to say I have kinda an intimate relationship with some of the manufacturers of these products over the past few years.

While it is true that some items MAY possibly cause an AFCI to activate it is less because of the “spark” and more because of a lack of FCC frequency guidelines on generated product frequencies…but thats another topic in of itself.

AFCI’s are very reliable at this stage in the game. Remember this is not new technology as it was conceived back in the mid 90’s, implemented in the 1999 NEC and enforced in the 2002 NEC. They are not NEW so to speak.

What is new is their rapid expansion into other areas of the home which is bound to always create other issues due to the massive production of products today and ever changing appliance development.

So when you say the AFCI is “exactly” looking for the “spark” it is only partially correct. The AFCI analyzes the waveform during the last scope of the half cycles within the waveform…if the “ARC” is present, it matches the processors bank of arc signatures then the system activates. So their is a process behind it, not just looking for “sparks”…if that was the case every switch you flipped that had a load attached, which creates a “make and break” situational arc would trip the AFCI devices…and they don’t.

Just some food for thought. If anyone would like AOT more detail on what AFCI’s really do and not speculate on them visit and read up and possibly take the online training course…maybe even ask NACHI if they will give some CE credit for it…Hey NICK…give them credit for it…:wink:

Website won’t let me register.

Did you register on UL first? I just did it again and had no problem getting registered and getting to the free course.

Don’t give up fella…the free course is well worth the effort.

I filled in all the registration information, clicked “Save”, and nothing happened. I’ll try a different browser.