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#170844 - 11/13/07 02:02 PM #12 THHN in 3/4" conduit.
Trick440 Offline
Member

Registered: 08/15/05
Posts: 248
Loc: Waterford, MI, USA
How are most guys doing this? What I'm hearing is only pull 3 #12 curcuits in 3/4" conduit. Is this what most guys are doing?

Please correct my math. If I pulled more, say 9 current carrying #12 conductors. Than it would be 2400w, derated to 1680w. So I could load the circuit up to 1680w.. (taking into consideration continuous loads)

I would like to know what most guys are doing. My background is residential, commercial is a different animal I'm still trying to grasp.

Thanks.
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#170846 - 11/13/07 03:05 PM Re: #12 THHN in 3/4" conduit. [Re: Trick440]
Trick440 Offline
Member

Registered: 08/15/05
Posts: 248
Loc: Waterford, MI, USA
I did a search and figured it out.

9 current carrying conductors, neutrals count as current carrying.. Would keep #12 rated for 20amps. So 4 circuits in a 3/4"
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#170850 - 11/13/07 05:02 PM Re: #12 THHN in 3/4" conduit. [Re: Trick440]
gfretwell Offline

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Registered: 07/20/04
Posts: 9045
Loc: Estero,Fl,usa
You could put 4 multiwire single phase circuits in a conduit. That looks like 8 circuits at 120v.
310.15(B)(4)(a)
If you didn't have any harmonic loads it could be 3 3p wye multiwires for 9 120v circuits.
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