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This is a new subpanel in a workshop and the electrician told me because it's new all circuits have to be AFCI and because it's an outbuilding it should be GFCI too.

So, I purchased these breakers in 20 and 15 amps, 20 for outlets, and 15 for the lights. My first issue was trying to run saws off the 20 amp and it would trip every time so I swapped that for a normal breaker (top left) and everything worked fine. Today I installed a single brand new LED light on the 15 amp circuit and the same thing, it would trip every time I turned on the light. Swapped that for a normal 15 amp and the light works fine.

Two different circuits, same panel, different loads, same result. Is there something I'm missing that is causing these to not work?

*** I know there isn't a ground rod yet, I have to run the wire from the outside in but I don't think that would affect this, right?

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  • When you buy a product it comes with documents - I know it's an old trope, but RTFM is really important, especially with electricity. If you're going to DIY, you can't just guess and use your guts to decide where to connect wires. There are rules and directions and you need to pay attention to them and understand them. Here you got lucky and did something foolish that resulted in an obvious problem that failed safely. It's very easy for you to make similar mistakes, however, that result in ostensibly normal operation but that hide extremely dangerous hazards. Be careful.
    – J...
    Apr 13, 2022 at 13:27
  • Why did you shortchange yourself by buying such a small panel? Sure, it suits your needs today but you've probably installed the sub panel because your main panel is already full. You'll be shocked at how quickly this one fills up, too, then you'll be adding another sub panel!
    – FreeMan
    Apr 13, 2022 at 16:24
  • @FreeMan I count twenty spaces, I think - that's enough for a pretty massive workshop. I mean, I get the mantra of "go bigger", but I don't think OP has cheaped out here at all. There's a ton of space in that panel.
    – J...
    Apr 13, 2022 at 17:22
  • eh, @J..., maybe you're right. I just eyeballed it and it looked small. I've read enough of Harper's <s>diatribes</s> er, <s>rants</s>, ummm comments on this that it's gotten to be a bit knee-jerk, I guess.
    – FreeMan
    Apr 13, 2022 at 17:31
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    @FreeMan I thought I heard Harper in there, lol.
    – J...
    Apr 13, 2022 at 17:34

1 Answer 1

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It looks like your photographs show the neutral wires landed on the neutral bar. This is wrong. For GFCI breakers, the neutral wire must be connected to the neutral screw on the breaker and the white pigtail wire from the breaker must be landed on the neutral bar.

A GFCI functions by comparing current between the hot and neutral. If they mismatch my more than a few ma, it assumes current is escaping to ground (maybe through a person) and trips. In this case, since the neutral current is bypassing the breaker, it cannot do the comparison.

Edit: correction to above. Because you are using Plug-on-neutral breakers, there is no pigtail but the neutral must still be connected to the breaker, not the neutral bar.

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    To add to what DoxyLover said, this is a Square D Homelite panel with a distributed neutral to work with their proprietary "plug-on" neutral AFCI/GFCI breakers. The advantage of these breakers is you don't need a "pigtail" (typically a neutral wire coiled like a pig's tail) to run to the neutral bar because they put the neutral bar right next to it and the longer smart breaker has a clip to catch the neutral right there. I'm not surprised that their attempts to simplify the box resulted in an incorrect wiring.
    – Machavity
    Apr 13, 2022 at 12:39
  • If somebody is so inexperienced they don’t just know GFCIs need the load neutral wire, so oblivious they don’t notice the second load terminal, and so confident that they don’t bother to read the instructions at all, I’m skeptical the presence of a pigtail would tip them off either.
    – nobody
    Apr 14, 2022 at 0:44

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