ECN Forum Forums Technical Discussion Electrical Theory and Applications Max current load

Not necessarily an NEC/code question. If I have two 10Awg circuits using 10/3 with ground MC cable and I put these together in parallel, what is the max current load that this will support?

Article 310.4 discusses conductors in parallel. Using the information there we find that paralleling #10 is only allowed in limited circumstances and based on Exception 1 (b) we find that parallel #10 (referring to table 310.16) carry 30 amps at 60 degree C (no increase in ampacity).

Thanks for the prompt reply. I find it interesting that the overall ampacity will not increase when two like cables are placed in parallel.


Thanks again..

That is not always the case.

2 cables with 1/0 or larger conductors will have double the ampacity. 3 cables with 1/0 or larger will have triple the ampacity.

In general there is little benefit from paralleling conductors smaller than 1/0 and you can only do it for specific installations.