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#130742 - 12/01/06 09:46 AM Max current load  
JakeJ1  Offline
Junior Member
Joined: Mar 2005
Posts: 3
charleston SC USA
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?


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#130743 - 12/01/06 11:13 AM Re: Max current load  
sabrown  Offline
Member
Joined: Dec 2002
Posts: 302
Ogden, Utah, USA
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).


#130744 - 12/01/06 12:25 PM Re: Max current load  
JakeJ1  Offline
Junior Member
Joined: Mar 2005
Posts: 3
charleston SC USA
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..


#130745 - 12/01/06 05:34 PM Re: Max current load  
iwire  Offline
Moderator
Joined: Jan 2003
Posts: 4,391
North Attleboro, MA USA
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.


Bob Badger
Construction & Maintenance Electrician
Massachusetts


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