No there is not any code, but there are standards on conduit spacing. The U.S. Iron and Steel Institute has the best chart. I'll look it up in a little while and try to post it to this thread.

Leo G said:

Is there a minimum space that I can have between conduits?

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Leo G said:

How many 12AWG THHN wires can I put into a 3/4" conduit, 1/2" conduit? I know it is 40% the cross sectional area of the conduit but I don't know the size of the wire with the insulation on it.

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For 3/4 you can have up to 16 #12 THHN's. For 1/2 you can have up to 9 #12 THHN's. When you start to fill a pipe this full, you get into concerns about derating the conductor's ampacity. When you have more than 3 current carrying conductors (hots and neutrals, not grounds) in the pipe, it builds heat. This causes a #12 conductor to be rated at less than 20 amps under certain circumstances, depending on how many conductors you fill the pipe with.

Leo G said:

Do I need to run a neutral for each hot in the conduit? Or will one take care of all the hots. (I think it's got to be one for each hot)

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For a single phase panel, two hots on different phases can share one neutral. For a 3 phase panel, three hots on different phases can share one neutral. If all your hots happen to originate on the same phase, then each need their own neutral.

Leo G said:

Thanks (MD or SP)

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No problem Leo. The bill is in the mail.

To use the chart, do as follows. If you have, for instance, a 1" conduit next to a 1/2 inch conduit look up 1/2" on the top of the chart and 1" on the left hand side. You can see that the proper spacing is 1-3/4" apart CENTER TO CENTER.

OK MD checks in the mail!!:Thumbs:

mdshunk said:

No problem Leo. The bill is in the mail.

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Where did you get this chart? is it in the NEC code book? Please reference!

mdshunk said:

To use the chart, do as follows. If you have, for instance, a 1" conduit next to a 1/2 inch conduit look up 1/2" on the top of the chart and 1" on the left hand side. You can see that the proper spacing is 1-3/4" apart CENTER TO CENTER.

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Doviman, the thread is 15 years old. mdshunk hasn't logged in in 5 years. If no one comes around to help, start a new thread.

This thread is ancient. That member hasn't posted in years.