Conduit fill

[865resi]

May I install 2 #2 and 2 #6 aluminum conductors in a 1" pvc system? Please forgive my ignorance in this section. I'm wanting to use 1" for this 80 amps. Thanks everyone.

 

[Dennis Alwon]

Yes, you can

 

[infinity]

Yes, you can

Dennis can you show the calculation?

 

[Dennis Alwon]

1" PVC is .333sq.in
#2 thwn-2 is .1158 x2 = .2316 sq. in
#6 thwn-2 is .0507 x 2 = .1014 sq. in

.2316 + .1014 = .333 sq. in

 

[Dennis Alwon]

Dennis can you show the calculation?

I was already on it. Thanks

 

[Dennis Alwon]

I noticed you are using alum. so that is usually xhhw-2????? If so that is a tad bit smaller so you are still good depending if I chose the correct insulations

 

[865resi]

Thanks, I really appreciate you.

 

[Dennis Alwon]

Thanks, I really appreciate you.

You do know that you can use #3 for 80 amps if the load is not more than 75 amps or you can use #2 with 90 amp breaker

 

[infinity]

I noticed you are using alum. so that is usually xhhw-2????? If so that is a tad bit smaller so you are still good depending if I chose the correct insulations

Sch80 will have less fill than Sch40.

 

[augie47]

Oddity,,,,
I did the math using XHHW-2 and exceeded the fill... #2 XHHW-2 is smaller than THWN-2, but #6 shows to be larger..... Not sure if there's a mistake in the Table or what ???

#2 .1146 X 2 = .2292
#.6 .0590 X 2 = .118
.2292 + .118 = .3472 1" Sch 40 = .333

 

[don_resqcapt19]

Oddity,,,,
I did the math using XHHW-2 and exceeded the fill... #2 XHHW-2 is smaller than THWN-2, but #6 shows to be larger..... Not sure if there's a mistake in the Table or what ???

#2 .1146 X 2 = .2292
#.6 .0590 X 2 = .118
.2292 + .118 = .3472 1" Sch 40 = .333

The product standards show that the required insulation thickness for those wire types to both be 30 mils for 6 AWG, and show 2 THWN-2 as having 40 mils of insulation and 2 XHHW-2 as having 45 mils.

 

[wwhitney]

Isn't most aluminum building wire "compact stranded"?

E.g. for XHHW, 2020 Table 5 gives diameters of 274 / 382 mils for #6 / #2 for regular stranding, while Table 5A gives diameters of 260 / 360 for compact stranding. And Southwire's data sheet for "SIMpull XHHW-2 Aluminum" gives diameters of 259 / 358, vary close to the Table 5A values.

Cheers, Wayne