I have a quick question...what is the maximum number of conductors 12AWG THHN that I can run in 1/2" EMT? I thought I read something like 10 or 12...but that seems way too many...also, do I have to consider the laoding and decrease the number of conductors accordingly? Thanks for your help!
EMT
- Thread starter epd807
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Re: EMT
9 conductors, per Table C1. But the problem is not whether to reduce the number of conductors. The problem is that you must reduce the ampacity of the conductors, per Table 310.15(B)(2)(a). With 9 conductors, presuming all are current-carrying, you derate the #12 to 70%, from 30 amps to 21 amps. But that turns out not to matter, because you have to protect a #12 with a breaker rated no higher than 20 amps anyway.
9 conductors, per Table C1. But the problem is not whether to reduce the number of conductors. The problem is that you must reduce the ampacity of the conductors, per Table 310.15(B)(2)(a). With 9 conductors, presuming all are current-carrying, you derate the #12 to 70%, from 30 amps to 21 amps. But that turns out not to matter, because you have to protect a #12 with a breaker rated no higher than 20 amps anyway.
pierre
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Re: EMT
Another thought to think about is the actual pulling of 9, 12 THHN conductors in 1/2 in conduit. It could be very difficult. Upsizing the conduit is not much more labor intensive and I believe you will save in the pull if the run is other than a short length.
The NEC permits 443, 12 THHN conductors in 4 inch EMT...
YEA RIGHT.
Pierre
[ December 10, 2003, 10:35 PM: Message edited by: pierre ]
Another thought to think about is the actual pulling of 9, 12 THHN conductors in 1/2 in conduit. It could be very difficult. Upsizing the conduit is not much more labor intensive and I believe you will save in the pull if the run is other than a short length.
The NEC permits 443, 12 THHN conductors in 4 inch EMT...
YEA RIGHT.Pierre
[ December 10, 2003, 10:35 PM: Message edited by: pierre ]
B
bthielen
Guest
Re: EMT
Another thought from the peanut gallery. There is almost nothing more frustrating than trying to add a single circuit and find that a new conduit run is necessary because what is available is already at capacity. The code defines the maximum but practicality suggests less.
Bob
Another thought from the peanut gallery. There is almost nothing more frustrating than trying to add a single circuit and find that a new conduit run is necessary because what is available is already at capacity. The code defines the maximum but practicality suggests less.
Bob
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