Is it possible/code to pull three #10 and three #8 wires thru a 3/4"
steel conduit?

Thanks,
Matt

It's probably not physically possible and definitely a code violation. You
also have to consider that when you pull multiple conductors through a
conduit, you must derate the capacity of the conductors as well



wrote in message
oups.com...
Is it possible/code to pull three #10 and three #8 wires thru a 3/4"
steel conduit?

Thanks,
Matt

wrote:
Is it possible/code to pull three #10 and three #8 wires thru a 3/4"
steel conduit?

If you have no turns, you could probably get 6 #10 through, but I don't
think it'll do you much good.

wrote:

Is it possible/code to pull three #10 and three #8 wires thru a 3/4"
steel conduit?

Thanks,
Matt


Looks good to me.

40% fill for 3/4" pipe is 0.2100 sq in.

3 #10 THHN = 0.0552 sq in.

3 #8 THHN = 0.1119 sq in.

Throw in a bare
#10 equip ground = 0.008 sq in.
(250-95 table)

TOTAL = 0.1751 sq in. (less than allowable fill)

--------------
Apply the de-rating factor from Note 8:

#10 THHN 40 Amp X 80% = 32 Amps, so 30 Amp protection is suitable.

#8 THHN 55 Amp X 80% = 44 Amps, so 40 Amp protection is suitable.

Jim

Speedy Jim wrote:
#10 THHN 40 Amp X 80% = 32 Amps, so 30 Amp protection is suitable.

#8 THHN 55 Amp X 80% = 44 Amps, so 40 Amp protection is suitable.

Electrically looks OK, but how's he going to get all that around the
bends?

He can use a wire pulling lubricant like Ideal Yellow77.
http://www.idealindustries.com/IDEAL...s?OpenDocument

"Nexus7" wrote in message
ups.com...

Speedy Jim wrote:
#10 THHN 40 Amp X 80% = 32 Amps, so 30 Amp protection is
suitable.

#8 THHN 55 Amp X 80% = 44 Amps, so 40 Amp protection is
suitable.

Electrically looks OK, but how's he going to get all that around the
bends?

) said...

Is it possible/code to pull three #10 and three #8 wires thru a 3/4"
steel conduit?

It depends on what the insulation is! It is the cross sectional area
that matters, as you are not supposed to exceed 40% of the conduit's
area.

If all these wires have T90 Nylon insulation, then their cross section
area is only 31.8% of the conduit's. If they are TW75, then they are 39.6%,
so they would also fit. If they are RWU75 EP, then they are 63.8% of the
conduit's fill.

I have a "conduit calculator" available for free at http://daxack.ca that
comes with cross-section data for a number of different types of wire.

--
Calvin Henry-Cotnam
"Never ascribe to malice what can equally be explained by incompetence."
- Napoleon
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Calvin Henry-Cotnam wrote:
) said...

Is it possible/code to pull three #10 and three #8 wires thru a 3/4"
steel conduit?

It depends on what the insulation is! It is the cross sectional area
that matters, as you are not supposed to exceed 40% of the conduit's
area.

If all these wires have T90 Nylon insulation, then their cross section
area is only 31.8% of the conduit's. If they are TW75, then they are 39.6%,
so they would also fit. If they are RWU75 EP, then they are 63.8% of the
conduit's fill.

I have a "conduit calculator" available for free at http://daxack.ca that
comes with cross-section data for a number of different types of wire.

Good link. Thanks!

R