ECN Forum
Posted By: smokey deration - 04/20/05 02:58 AM
how many #12 thhn"s can i legally squeeze in a 3/4 in conduit? the conductors are feeding plugs and lights in a commercial building?
Posted By: Steve T Re: deration - 04/20/05 03:47 AM
Per appendix C of the 99 NEC--16.

Don't forget to derate according to 310-15.
Posted By: frenchelectrican Re: deration - 04/20/05 03:48 AM
i will say 12 to 15 but depending on which kind of conduct pipe you are using and keep in mind you have to derated also because it will be more than 3 current carry conductors

Merci, Marc
Posted By: Steve T Re: deration - 04/20/05 03:58 AM
Oh yeah--that 16 is in EMT which I assumed you would be using. I know us Chicago guys forget about that other stuff.
Posted By: George Little Re: deration - 04/20/05 11:42 AM
Steve- Just for a smart ass comment EMT is not conduit [Linked Image]
Posted By: Redsy Re: deration - 04/20/05 09:44 PM
George,

One smart--- comment deserves another.
Whether EMT is conduit or not depends on how old you are.

[Linked Image]
Posted By: George Little Re: deration - 04/20/05 10:53 PM
Guess your right Redsy- I'm a little long in the tooth.
Posted By: Roger Re: deration - 04/21/05 01:03 AM
Although it is technically tubing, the second sentence of 358.24 (2002 NEC) calls it conduit. [Linked Image]

Roger
Posted By: Steve T Re: deration - 04/23/05 03:29 AM
Thanks Roger for saving my butt!!

I really wish they would make a clear definitive distinction between the two though. It would have saved us all at least a combined 5 minutes of typing. [Linked Image]
© ECN Electrical Forums