Wire size

Had a #12 wire being used for a sump pump with a #15 wire spliced into the box going into a room outlet. The circuit breaker was a 20 amp breaker. I wrote it up as improper conductor sizes connected together recommend evaluation by a licensed electrician. The realtor called and told me the electrican said it was okay. Am i wrong?

You’re correct. The #14 AWG conductor needs to be protected at 15 amps according to NEC 240.4(D) unless if falls under part (E) or (G) which in this case it does not.

240.4 Protection of Conductors.

(D) Small Conductors. Unless specifically permitted in 240.4(E) or (G), the overcurrent protection shall not exceed that required by (D)(1) through (D)(7) after any correction factors for ambient temperature and number of conductors have been applied.
(D)(3) 14 AWG Copper. 15 amperes

No, the realtor/“electrician” is wrong.

You may want to consider that it doesn’t need to be evaluated again but simply repaired/replaced.

Leave your findings and let the client decide whom to believe. Tell them to have electrician put it on paper that it is ok.

I doubt the realtor even talked to an electrician. It is a simple/quick replacement and I don’t see why an electrician would even hesitate to replace the wire.

I always run a sump circuit as dedicated, but that’s another story/issue.


What is the amperage rating on the pump? If it only pulls a few amps it will never overload the wire. Thats why the electrician said it was ok probably. I would still called it out as being mismatched, but I doubt it will ever be an issue, if it is the only thing on that branch of wiring. Now if you add a few more things, then you will have problems.

I don’t think the problem is the pump only pulling a few amps under normal condition. It is if there is a problem with the pump and it starts pulling too many amps when it is broken. The small wire could melt and start a fire before the OCD trips.

Well then replace the breaker with a 15 amp. Problem solved!!

According to NEC Table 310.16, 60° C, #14 conductors are rated for 20 amps. For an application like this 240.4(D) limits their protection to 15 amps. It’s likely that at 20 amps this circuit could operate forever without damaging the conductor.

My issue is with other outlets being on the same circuit as the sump or ejector pump. If something else that is plugged in trips the breaker, you may not know until it’s too late.


I saw a 14/2 (AC unit) protected with 100Amps breakers last week…