Current capacity of two paralles 12 ga wires.

shadetree_bobJune 9, 2012

We all know that a 12-2 wire is rated for 20 amps for house wiring. How much current could two 12 -2 gauge wires running in parallel for about 25 feet carry. Assuming all connections are up to code?

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"Assuming all connections are up to code"

since you can not (per NEC) parallel anything smaller than 1/0

    Bookmark   June 9, 2012 at 10:38PM
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I should have known better than to ask a question like this here among all the "experts". I should have said all connections are tight and secure. What I wanted to know was how to answer some one that asked me this as strictly a theoretical question. There is no intent to use something like this in any building wiring of any type. No hidden meaning or plans to use this anywhere, just a simple question. If one wire will carry 20 amps, will two of the same size in parallel theoretically have double the capacity. I did not realize that I had to lower the question to a fifth grade level to get any sort of simple answer.

    Bookmark   June 11, 2012 at 9:35PM
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didn't get what you wanted so you're going to be an ass hole? You internet tough guys are so awesome...

Seems pretty detailed for a strictly theoretical question if you know the distance it would be.

This isn't an electrical theory forum or a play to get scab advice, go play tough guy somewhere else.

    Bookmark   June 11, 2012 at 10:37PM
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Ron Natalie

The current rating on wires is based on the rules involving the heat dissipation, etc... there's NO WAY to answer your question. There's no way to guarantee that small gauge NM is going to be balanced enough to support larger currents in parallel.

In an ideal situation, the resistance of paralleled conductors is halved, which means you can carry twice the current for the same voltage drop. However, there are more issues to ampacity than just DC resistance.

    Bookmark   June 11, 2012 at 10:39PM
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shadetree_bob, your second post in this thread is completely unwarranted and makes you look like a jerk.

And believe me, I know about looking like a jerk.

    Bookmark   June 11, 2012 at 11:52PM
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