CALC: Conduit Capacity Calculator

Started by MountainDon, July 11, 2008, 09:44:28 PM

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Ever wondered how to calculate the conduit size for a particular number of wires of a given size? Below are a couple of useful links. The first to an online calculator, the second to a chart so you can practise your own math skills.

This is not a be-all / end-all answer to the question. There are other factors that must be accounted for according to the NEC. For example, at a certain point the number of cables will cause a de-rating factor to be applied. This is due to heat build up from the electrical flow and non circulating air. Anyhow this is a place to start if you're wondering.

Conduit Calculator

Conduit Capacity Chart
Just because something has been done and has not failed, doesn't mean it is good design.