National Electrical Installation Standards

Standards as High as Your Own

Monday, August 5, 2019


Can you use 12ga thhn stranded wire in EMT conduit coming from a 20 amp breaker that feeds a few outlets and flood lights (led)?

What are the spacing dimensions required to secure conduit?

I was getting bids to run another 220v circuit into the laundry room and was wondering why you couldn't run two 220v outlets from one breaker?

I'm not an electrician but I've come across a few questionable things licensed electricians have done so to make me feel better I like to understand the logic behind the installation.

Thanks, Justin


Hey Justin thanks for your questions.

1) Yes 12 AWG copper stranded conductors can be protected by using a 20 ampere circuit breaker - if the conductor does not have "reduced" ampacity due to adjustment factors or correction factors as stated in 240.4 and 310.15. The conductor would also need to have sufficient ampacity for the load as stated in 210.19.

2) Support spacing distances vary based on the type of conduit, raceway or cable. See the XXX.30 section in the Article in NEC Chapter 3 for maximum spacing distances and the distances for securing at terminations.

3) Branch circuits can supply more than one receptacle outlet if the conductors are suitable for the load, properly protected from overcurrent, and meet any specific requirements depending on what they are installed for as stated in Article 210, 240.4, and 310.15.

Using a Qualified Person, as that term is defined in Article 100, who is also locally licensed is much better and safer than trying to do the work yourself.

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