Can I substitute two 14-gauge wires together for one 10-gauge wire? Using it from the generator RB-30 remote box, to the transfer switch inside a 6', 10-3 whip in the basement.

  • I'd worry that one would get disconnected and all the current would go through one undersized wire – ratchet freak Nov 2 '14 at 20:15
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    @ratchetfreak - Fails the fail safe rule, one long hot fusible link... – Fiasco Labs Nov 2 '14 at 21:22
  • In addition to not being failsafe, parallel runs that are not sufficiently parallel/twisted/braided can introduce impedance problems for AC current. I might be wrong, but I remember having a debate with someone a long time ago and back then I was convinced this was the case! – Paul Nov 3 '14 at 17:21

If the installation needs to comply with US NEC, 310.4 forbids paralleling conductors smaller than 1/0 (with some limited exceptions that do not apply to the described installation.)

310.4 Conductors in Parallel

Aluminum, copper-clad aluminum, or copper conductors of size 1/0 AWG and larger, comprising each phase, polarity, neutral, or grounded circuit conductor shall be permitted to be connected in parallel (electrically joined at both ends).

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  • The requirements of the equipment take precedence. – user23752 Nov 3 '14 at 20:20
  • Nice stalking horse. Do you purport that the equipment has a code-violating requirement to be installed with paralleled 14 gauge conductors? If not, exactly what relevance does your comment have to my answer? I fail to see any. – Ecnerwal Nov 4 '14 at 3:18
  • The wire size is irrelevant because the equipment is not listed for parallel conductors. Or to put it another way, parallel 1/0 conductors would not meet code in this case. Your answer implies that they would. The code has to be considered comprehensively, not in dribs and drabs. And the most restrictive provisions take precedence. – user23752 Nov 4 '14 at 4:34
  • Where does it say that it's otherwise forbidden? – Mazura Nov 4 '14 at 4:38
  • My answer implies nothing of the kind, since the question is about substituting 2 14Ga wires for a single 10Ga wire... – Ecnerwal Nov 9 '14 at 22:33

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