[Itsonlywes]

How many # 10 conductors are allowed in 1" emt?

 

[bkmichael65]

You can put 15 #10's in 1" emt, but derating is another issue

*that's 15 if you're using thhn*

 

[wildleg]

16 thhn. other articles apply. table c.1 however, that's fill.

your thread title is "derating", so I'm gonna say 3 current carrying conductors at 100%. 310.15 B 3 A

 

[erics37]

How many # 10 conductors are allowed in 1" emt?

What kind of insulation? What are the conductors supplying? Any non-coincident loads? Control wiring? What's the ambient temperature? Is it on a rooftop exposed to sunlight?

But I'd say you could cram about 50 of them in there if you really tried :thumbup:

 

[Joefixit2]

I'd say you could cram about 50 of them in there if you really tried :thumbup:

Yes I'd say any handyman worth his salt could get 50 of them in there, or at least four 10/3 romexes using an SLB or two. The handymen around here are good at putting 10/3 romex in 1/2" pipe with SLBs and elbow "Jakes". When we demo their crap it's so hard to get it out for scrap we just slice the SLBs and Jakes off with a Sawzall.

 

[Itsonlywes]

Thhn, 20 amps, in doors. Normal ambient temperature

 

[wildleg]

310.16 #10 ampacity 40 amps for derating purposes

310.15 B 3 A 40amp/20amp = 50% -> 20 conductors max

table c.1 Emt 1" -> 16 thhn #10 max

so at 20 amps, you can put 16 of the #10 thhn in the 1" pipe

(you can do the manual fill calculation also, and see if more will fit - sometimes that's good for a couple more, sometimes not)