Why does an afci trip when the neutrals of two different afci circuits are tied together in a switchbox?

Since an AFCI and a GFCI work on relatively the same basic principle, i.e.unbalanced current flow, tying 2 neutrals together from 2 different circuits makes the circuit think it is unbalanced and trips.

Since an AFCI and a GFCI work on relatively the same basic principle, i.e.unbalanced current flow, tying 2 neutrals together from 2 different circuits makes the circuit think it is unbalanced and trips.
I fully agree.

I hope this is a rhetorical question. You should never tie the neutral from two different circuits together.

Can I derive 120v for a light from a 240v line feeding a spa? Or do you recommend running a separate line.

No you cannot. The 240V circuit is a dedicated circuit and cannot be tapped for a 120V circuit.

Question, just curious, but the circuit to the spa, is it 120/240 or a straight 240V.

Either way, you cannot tap the circuit.

Sir I didn't got u please explain me the reason.plz send your answers on my email [email protected]

The answer is physically yes . You could do this . Is it in compliance with the national electrical code ? The answer is emphatically no , no , no . The first thing that stands out as a 1000 pound gorilla in the room is the fact that the hot tub wiring is protected off the 50 amp breaker . The wiring you are connecting for 110 V is rated at 15 A . As well you could easily electric youth somebody in the hot tub . As well if you installed the ground fault circuit interrupter device as per the national electrical code . The moment that you energized anything on the 110 V circuit your power would be shut off . If electricity leaves the ground fault circuit interrupter breaker and does not return on either the other hot leg or the neutral the ground fault circuit interrupter breaker will send the disparity in current and shut off the circuit . In short you don't power things from other circuits in a house . You crawl a little bit further and run the wire off the main electrical service .

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Do not do any electrical work if you do not hold a State License .

Do not do any electrical work if you do not hold a State License .

States vary regarding who can install electrical wiring. Unless regulated by the state/ city/ county where you live, anyone can wire a house as long as it meets the NEC. There is nothing in the NEC that says only licensed electricians can use this book or install wiring. I am not a licensed electrician but have wired 2 houses from the main panel out, had both permitted and inspected and had no issues.

U should never share a nutruel to an afci or FCI. The will always trip.

Plese do not use chat type, use full words, use spell checker, and accurate terminology.


U should never share a nutruel to an afci or FCI. The will always trip.

Your statement should read as follows:

"You should never share a neutral to an AFCI or GFI. The will always trip."