Finishing my basement and had some help with our electrical install. I'm located in NJ btw, being that we installed new branched circuits (about 18 outlets and 16 LED lights), I had to use 3 breakers. For the new circuits, I used 3 AFCI (Eaton, CH, 15A, 120v) breakers, the pigtails connected to my neutral bar. However, each existing neutral is wired into each lug-hole with a ground, all other breakers in the box are standard, non AFCI.

When I test with it hooked up and turn the light switch on (with only 4 LEDs connected, for now), it trips right away. Which to me means a ground fault. Our home is from ~1997, all inspections passed then as the sticker on the panel indicates this. The panel actually looks really well done inside, no corrosion either. Note this is not a sub-panel, it's the one and only.

Here is the breaker:

All is well if I leave the pigtail disconnected, the breaker stays on, but the test functions do not work and it will probably not pass an inspection, which I require for our permit. Any thoughts? The only thing I can think of is the following:

Get an AFCI Type CH breaker without the pigtail Get a 2-Pole AFCI Type CH Breaker



2 Answers 2


You need to move the neutrals for those circuits onto the breaker neutral lugs

Many AFCI breakers, yours included, have a ground-fault trip in them, set at around 30mA, in order to catch arcs and other firestartingly hazardous leakages to ground. As a result, these AFCIs not only need their neutral pigtails connected to the neutral bus, they need the circuit neutrals connected to their neutral lugs, or else they will remind you of that requirement by instatripping on startup due to what appears to be an absolutely colossal ground fault (all the current going out through the breaker, yet none of it returning via the breaker neutral path). (This is also required if you ever want to install a GFCI or DFCI breaker into your panel, by the way.)

  • Hi ThreePhaseEel, to clarify, my panel has two bus bars, left and right side. The right side has all previous home wiring neutrals lugged with a ground wire. My 3 new ACFI breakers have hot and neutral wires (for the new branched circuits created) connected. I only removed the pigtail from the left side bus bar for the LED lighting circuit as it causes an insta-trip. By doing so, it looks like the "Test" function on the breaker no longer works as well. To summarize, only the pigtail is disconnected, the Hots and Neutrals are connected. Why would the pigtail cause a trip?
    – Amit T
    Jul 9, 2020 at 13:54
  • 2
    @Amit If you had the hot and neutral on the AFCI breaker, and you disconnected the pigtail, the circuit would not work at all. .... So I think you and ThreePhaseEel are “talking past each other”... maybe it’s time for photos. Jul 9, 2020 at 14:13
  • What is a "DFCI" breaker? The FLA alphabet soup is getting thicker...
    – FreeMan
    Jul 9, 2020 at 14:46
  • @FreeMan, it's a Dual Function Circuit Interrupter -- an AFCI + GFCI in one breaker.
    – Nate S.
    Jul 9, 2020 at 16:39
  • Ah, thanks, @NateS. I've seen those listed as AFCI/GFCI, but never DFCI. #TIL
    – FreeMan
    Jul 9, 2020 at 16:52

Each circuit's neutral MUST go to the AFCI breaker

Perhaps you cannot easily see this neutral terminal, but it is on the breaker underneath the hot terminal (not side by side).

You ran those neutrals to the neutral bar the way you do with plain breakers, and that is simply wrong. You seem very fixated on doing it that way, and it is simply wrong. Your AFCIs will never work if you insist on doing it wrong.

Your AFCI pigtails MUST go to the neutral bar

And that is for very good reason. If you have done the above correctly, then the circuit will only work if you connect the pigtails.

You have discovered a glitch in your AFCI where if you disregard both instructions above, the circuit "seems to work". However you have sabotaged the AFCI protection, it does not work at all, and you might as well not have wasted the $40 and gone with a plain breaker. If your solitary objective is to fool the inspector, this might work, but it is asinine.

If you wire the AFCI correctly, and it trips, you have an arc or ground fault. FIX IT.

Guess what. When you apply fault-detection devices to an existing (or new) circuit, it sometimes detects a fault! Goshy wow, that's the whole reason we install them, right?

So, when you wire up a fault detection device correctly and it detects a fault, then most likely, it is exactly what it says on the tin: that type of fault.

So you should start by assuming the fault detector is reporting truthfully, and go hunt down that fault in the normal manner for doing so.

I think when people don't know how to do that, they fall back on blaming the detector. Don't fall into that mental trap. Learn to do the above.

Here are the instructions for your AFCI breaker. I affirm everything ThreePhaseEel discusses. ThreePhaseEel is a master expert at breakers, but you don't need to be one to understand the problem here.

As for the "I don't have any neutral spaces left"....

Consolidate up to 3 grounds per screw, but only 1 neutral.

There are a small number of electricians who group each circuit’s neutral and ground together and stick them under the same screw on the neutral bar. Together. Can’t do that. That’s 2 wires per lug, and they’re only listed for one neutral.

Now if you read the panel labeling carefully, CH panels can have 2 to 3 grounds can go under a single screw, but only one neutral because of NEC rules.

So pull ‘em all out. Clump the grounds 2 or 3 per screw (whatever the panel labeling says is allowed). That will free up a lot of spaces, leaving you enough for 1 neutral per screw, alone.

All the screws need to be torqued to panel spec with a torque screwdriver.

This is a mildly dangerous situation. It happens all the time where a wire on a neutral bar loses contact with the bar, usually because of being under-torqued. If the neutral and ground lose contact together, but still are connected to each other, it will electrify all the grounds on the circuit - touch a light switch screw or an appliance metal case and blammo!

And if you’re thinking “oh no, the neutrals are all too short to reach the breakers, because Mr. Snippy went through my panel ‘to make it neat looking’, and cut all the wires down to barely the length they need to go where they’re going right now”... that happens a lot. You will need to extend the neutrals with wire nuts. This is why Mr. Snippy is flat wrong. Harper’s Law is every hot and neutral must be long enough to reach every space in the panel. You can still have “neat”, but you just have to tuck the extra up somewhere. I like to overshoot the breaker and then come back.

  • Thanks for the notes, I should have been clearer. I do in fact have the circuit's neutral white wire connected to the correct neutral terminal on the AFCI breaker, triple checked. The AFCI breaker has 2 terminals (line + neutral) and both are connected to the circuits romex 14-2 wiring; I did not connect the circuit's neutral wire to the neutral bar at all, neither the left or right side bars. The AFCI breaker has a pigtail wire that is NOT connected to the neutral bar on the right, when I connected to the left bar, it would trip once the LEDs were turned on. I left it disconnected.
    – Amit T
    Jul 24, 2020 at 22:19
  • @AmitT Yes, I believe you have an arc-fault problem in the circuit, then. Or possibly a ground-fault problem, as AFCIs can trip on those too: Did you join that circuit's neutral to any other neutrals? (sometimes when people have 2 circuits in a box, they connect all the neutrals; you're not supposed to do that, but you could always get away with it before). So you need to divide and conquer: break the circuit (hot AND neutral) at various points until you find which part of the circuit the problem is. Jul 26, 2020 at 18:30
  • The more I think about this, the more sure I am that the circuit itself is improperly wired. The things on it are using this hot wire, but returning neutral current on another wire, such as another circuit's neutral, or ground. Did you miswire the circuit because that was the only way it would work? Jul 26, 2020 at 18:44

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