am i doing this right?

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laketime

Senior Member
I am figuring out wire fill of different sizes for EMT.
3/4" EMT @40% fill is 137mm2
(3) #6thhn - 13.30mm2 x 3 = 39.9mm2
(1) #10 thhn- 5.261mm2 = 5.261mm2
(6) #12 thhn- 3.31mm2 x 6 = 19.86

That totals 65.021mm2 of wire. That legally fits in a 3/4" EMT correct?
 

augie47

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Location
Tennessee
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State Electrical Inspector (Retired)
It appears you got your wire dimmensions from table 8... thats bare conductors.. for your THHN go back to Table 5, pg 678 ('08)
(I think your total will be .253 = over fill)
 
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laketime

Senior Member
It appears you got your wire dimensions from table 8... thats bare conductors.. for your THHN go back to Table 5, pg 678 ('08)
(I think your total will be .253 = over fill)

Duh:roll: your right I was using bare conductor sizing. Thanks for the help.
 

jmellc

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Location
Durham, NC
Occupation
Facility Maintenance Tech. Licensed Electrician
Duh:roll: your right I was using bare conductor sizing. Thanks for the help.
Well, who says they have to be insulated? If you can figure out a way to keep the wires from touching each other, the conduit, the boxes or the panel, what's the problem?
 

laketime

Senior Member
The how about this one. The wire for a 10kW back up generator?

I=P/E

I=10,000/220

I=45.45amps

wire size #8awg thhn
 

augie47

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Location
Tennessee
Occupation
State Electrical Inspector (Retired)
You might find your 10kw generator has main lager than 40 amp... if so you would need to adjust your wire size for the OCP.
 

augie47

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Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
Then, IMO, a #8 (THWN) would be fine if your terminations are rated at 75? (110.14). In a NM or SE you would need a #6.
 

laketime

Senior Member
Then, IMO, a #8 (THWN) would be fine if your terminations are rated at 75? (110.14). In a NM or SE you would need a #6.

Thanks for your help. I have 20 years of experience in commercial electrical but we always ran the projects off of fully engineered drawings. Mistakes were found on the drawings sometimes and we could correct that. Now that I am out on my own sometimes I feel like a total rookie again :roll:.
 
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