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I am wiring a house that I built, and code says I need an AFCI for the bedroom circuit.

The panel that I will be installing this AFCI breaker in is a subpanel, so my ground/neutrals are on 2 separate buses on opposite sides of the breaker panel.

Can I tie the AFCI white pigtail wire in to the ground bus, or does it need to go over the neutral bus? The reason I'm asking, is because the wire is kind of short. To run across to the neutral bus, I would have to splice an extension to the the AFCI white pigtail wire, and run the extension over to the neutral bus. How do you guys work with a situation like this?

I have all my 120v breakers on the left side (where the ground bus is), and my 240v breakers on the right side near where the neutral bus is.

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    At risk of stating the now-blazingly-obvious, it's probably better to put the 120V breakers on the neutral side for this reason, or scatter them around. A house following modern code takes a lot of GFCI and AFCI breakers, every one has a pigtail and most are 120V. Whereas many 240V circuits don't use neutral at all. I prefer GFCI breakers to outlets because it protects you from water in the junction box. You absolutely must separate ground/neutral in a sub-panel and it's good practice in a main panel too. – Harper Apr 26 '16 at 4:47
  • Thanks for all the replies. Actually out of all my 240v circuits, the only one that doesn't require a neutral is the water heater, everything else does.... I want to keep breakers categories and together for a neat easy to understand layout so I just ran a extension via a wire nut to the neutral bar. I don't think it should have any problems passing inspection but I guess I'll find out. I only need 2 AFCIs anyways (bedroom and smoke detectors) for my area. – Jrowe Apr 30 '16 at 1:17
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The AFCI wire needs to connect to the neutral bus. Put it on the other side, or add on to the length of the wire with a wirenut.

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    I'm not doubting you at all, longneck, but do you have a NEC reference for the OP showing that an extension is allowed, just in case someone questions it during the inspection, or is this a commonly allowed procedure? – FreeMan Apr 25 '16 at 17:29
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    This is a commonly allowed procedure. It's a myth that the NEC doesn't allow wirenuts in a breaker panel. – longneck Apr 25 '16 at 17:33
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    @freeman, it is rare that the NEC specifically allows something like this. Basically if its not expressly forbidden it is allowed. – Speedy Petey Apr 25 '16 at 22:35
  • Thanks for all the replies. Actually out of all my 240v circuits, the only one that doesn't require a neutral is the water heater, everything else does.... I want to keep breakers categories and together for a neat easy to understand layout so I just ran a extension via a wire nut to the neutral bar. I don't think it should have any problems passing inspection but I guess I'll find out. I only need 2 AFCIs anyways (bedroom and smoke detectors) for my area. – Jrowe Apr 30 '16 at 1:20
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If space permits, you could also run an additional isolated neutral buss bar (connected to the existing neutral bar, and isolated from the box/ground.) My main panel has 3 interconnected ground buss bars (left, top, right - power entry at bottom) to keep it convenient. Small change in the grand scheme of things. Use adequately sized wire for the interconnection.

isolated buss bar

  • That's an awesome way to do it. How do you size the interconnect wire? – Harper Apr 26 '16 at 4:50
  • Well, you could do a load calculation, but it's a short wire and the future use is variable, so it's often just "what is the biggest wire that the buss bars (at each end) will take" - many have different sized holes, unlike this picture. So, start with what the largest wire your current bar will take is, and then go shopping for a buss bar to match that and enough wire to connect the two. If it seems like that's likely to be undersized, get two and replace the one you have. Does not need to be any larger than the feed wire, though. – Ecnerwal Apr 26 '16 at 14:25
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My guess about the wire nuts is that a load center is not a junction box. My inspector passed me with the same issue.

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    This is a myth. True a panel is not a junction box, but splices like this ARE allowed in a panel. – Speedy Petey Apr 25 '16 at 22:36
  • Thank you Speedy, that question has come up for me a lot. – Harper Apr 26 '16 at 4:38

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