Mike Holt newsletter-NEC Questions 010

[kthbrwn]

Q2. There is an on going practice among electrical contractors in my area to connect a short piece of 14 AWG wire to the 12 AWG in a receptacle box. The purpose of this is to facilitate the use of the push in connectors on the back 15A receptacles on a 20A circuit. When I ask how is this permitted? They cite the fact that the device is rated 15A and therefore this practice is allowed according to the branch-circuit tap rules. Is this true?

A2. No. The minimum size conductor for a 20A circuit is 14 AWG [310.5].

Would'nt this be allowed according to Table 210.24? For a 20A circuit rating, one can use 14 for a tap. Don't think 310.5 is a reference to this question, either.

 

[iwire]

Re: Mike Holt newsletter-NEC Questions 010

No you can not use a 14 AWG tap on a 20 amp circuit for outlets. Take a look at

II. Branch-Circuit Ratings
210.19 Conductors ? Minimum Ampacity and Size.

210.19(A)(2)Multioutlet Branch Circuits. Conductors of branch circuits supplying more than one receptacle for cord-and-plug-connected portable loads shall have an ampacity of not less than the rating of the branch circuit.

Then there is always 240.4(D) requiring 12 AWG for 20 amp breakers.

Yes the reference and answer was a mistake, I emailed Mike Holt and he got right back to me apologizing for the mistake.

[ March 07, 2004, 10:01 AM: Message edited by: iwire ]