HELP: AFCI circuit from hell (15A keeps tripping)
#1
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Please help. As part of my electrical inspection, I was told I need to install AFCI breakers for the bedroom addition. I have two 20A breakers and one 15A breaker.
The two 20A went in with no trouble -- they work perfectly.
The 15A keeps tripping. It won't even turn on! Every time I flip the breaker switch, it immediately switches off.
I have looked at the installation instructions and confirmed that the load power line, pig-tail neutral, load neutral, and ground wire are all correctly attached.
This 15A breaker powers four lights. One section is a 3-way for a starwell. Everything worked just fine when I had a standard 15A breaker in place, but when I put the 15A AFCI in, it just trips and trips.
The two 20A went in with no trouble -- they work perfectly.
The 15A keeps tripping. It won't even turn on! Every time I flip the breaker switch, it immediately switches off.
I have looked at the installation instructions and confirmed that the load power line, pig-tail neutral, load neutral, and ground wire are all correctly attached.
This 15A breaker powers four lights. One section is a 3-way for a starwell. Everything worked just fine when I had a standard 15A breaker in place, but when I put the 15A AFCI in, it just trips and trips.

#2
Just to make sure, the ground wire is not connected to the AFCI correct? Make sure there is no grounds touching the load side neutral. That will trip an AFCI right away.
You can test the breaker buy disconnecting the wires from the breaker and see if it will hold. If it does, there is a problem in your circuit.
Start in the middle of the circuit and disconnect it from the rest of the circuit. Test to see if the breaker will hold. If it does, the problem is in the dead half. If not, the problem is in the other half of the circuit. Keep going until you pinpoint the problem area.
You can test the breaker buy disconnecting the wires from the breaker and see if it will hold. If it does, there is a problem in your circuit.
Start in the middle of the circuit and disconnect it from the rest of the circuit. Test to see if the breaker will hold. If it does, the problem is in the dead half. If not, the problem is in the other half of the circuit. Keep going until you pinpoint the problem area.
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To clarify, the 15A AFCI breaker is wired correctly. The ground goes to the sub-panel ground bar, the neutral (W) goes to the breaker, then the pig-tail neutral goes out to the neutral bar, and the hot (B) goes straight to the breaker. I have also double-checked to make sure the hot and neutral are going into the correct terminals on the breaker.

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Ok, when I remove the neutral and hot from the breaker and flip the breaker on, it works just fine. Since it's still tripping even with my minimal circuit, there must be something faulty in the first part of the run.
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I think I may have figured it out. Looks like the ground and neutral were touching the same plate on the light fixture. I disconnected the ground from the simple light fixture and now it's working. Next, I'll secure the rest of the circuit back in and see if it will run.
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NEC AFCI requirement apply to lighting?
Just curious, but the inspector knew that this was a lighting only circuit? I thought the AFCI requirement only applies to branch circuits powering outlets?
Also, how did you make those great schematic drawings?
Also, how did you make those great schematic drawings?
#12
Mnmattmn, it depends on which cycle you are required to adhere to. Current NEC requires all single circuits not on GFCI to be AFCI. Older versions started with bedrooms only.
#13
the inspector knew that this was a lighting only circuit? I thought the AFCI requirement only applies to branch circuits powering outlets?
210.12 Arc-Fault Circuit-Interrupter Protection.
(A) Dwelling Units. All 120-volt, single phase, 15- and
20-ampere branch circuits supplying outlets installed in
dwelling unit family rooms, dining rooms, living rooms,
parlors, libraries, dens, bedrooms, sunrooms, recreation
rooms, closets, hallways, or similar rooms or areas shall
be protected by a listed arc-fault circuit interrupter,
combination-type, installed to provide protection of the
branch circuit.
There is no distinction by type of device. Powered fire and intrusion sensors are included, for example. When was the last time you saw a general service residential circuit that was all receptacles, BTW?
(A) Dwelling Units. All 120-volt, single phase, 15- and
20-ampere branch circuits supplying outlets installed in
dwelling unit family rooms, dining rooms, living rooms,
parlors, libraries, dens, bedrooms, sunrooms, recreation
rooms, closets, hallways, or similar rooms or areas shall
be protected by a listed arc-fault circuit interrupter,
combination-type, installed to provide protection of the
branch circuit.
#16
I think that AFCI is a great improvement now that they're starting to get the kinks ironed out, I think that the industry weighed in heavily on it - but they often do on devices - and I think that $30 and up is absolute highway robbery.
There oughta be a law.
There oughta be a law.

#17
Just curious, but the inspector knew that this was a lighting only circuit? I thought the AFCI requirement only applies to branch circuits powering outlets?
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It seems intentional that the code uses "outlets" rather than recepticals or luminaries or anything more general. Lighting loads do not require GFCI breakers, why would they require AFCI?
The ironic thing about AFCI is that the houses that benefit from them the most are also the least likely to have them (as they are typically only checked for in new work or remodeled rooms). Doesn't bother me to install them either, cheap insurance!
The ironic thing about AFCI is that the houses that benefit from them the most are also the least likely to have them (as they are typically only checked for in new work or remodeled rooms). Doesn't bother me to install them either, cheap insurance!
#19
It seems intentional that the code uses "outlets" rather than recepticals or luminaries or anything more general.

Lighting loads do not require GFCI breakers, why would they require AFCI?
AFCI protection is designed to protect the wiring and the structure from the damage that can result from an unchecked electrical arc. That't why it's required for the entire circuit, from the panel outward - so that it can protect against the errant nail penetrating a cable, for example. Of course that also protects everyone in the dwelling unit also.
Two different purposes, two different technologies, one common aim: life safety.
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