Wires in parallel for oven

[lincb]

Can you run wires in parellel for a double oven? I ran into a situation where there were two sets of #12 ran for a 40A circut and not quite sure if its ok.

 

[jumper]

I do not think this is legal. Parallel is suposed to be 1/0 or bigger I believe.

 

[ron]

Too small for parallel. 1/0AWG or bigger.
Were they two ovens or one doub;e with a single termination?

 

[jumper]

I found it 310.4 in 05 code.

 

[lincb]

It was previously two singles and the guy who installed the new double had just combined the existing wires and upped the breaker to a 40

 

[roger]

It was previously two singles and the guy who installed the new double had just combined the existing wires and upped the breaker to a 40

It would probably work fine forever but it is a code violation.

Roger

 

[dbuckley]

Even if paralleling was permissible, which it isn't because of the wire size, there's the other matter of identical lengths, construction, thermal state etc, and I suspect that a couple of independently run #12s are unlikley to be of identical length, so they shouldn't be paralleled on that basis either.

Conclusion: its a bad job.

 

[Dennis Alwon]

Conclusion: its a bad job.

I would say that is a good assessment. :grin:

 

[roger]

Even if paralleling was permissible, which it isn't because of the wire size, there's the other matter of identical lengths, construction, thermal state etc, and I suspect that a couple of independently run #12s are unlikley to be of identical length, so they shouldn't be paralleled on that basis either.

Conclusion: its a bad job.

But, if it weren't for 240.8 we could just add another breaker on the same leg to feed one of the conductors and we could call it a double fed ring circuit. :grin:

Roger

 

[broadgage]

The use of two conductors in paralel is a clear violation of the NEC but is most unlikely to be dangerous in practice.
Here in the UK it would be permitted in many circumstances, and whilst codes and regulations vary, the laws of physics are the same everywhere.

 

[dbuckley]

The use of two conductors in paralel is a clear violation of the NEC but is most unlikely to be dangerous in practice.

Thats the kicker. Anyone with sufficient nouse can figure out that this is probably OK, and anyone with a clamp meter can check that it is actually paralleleing and loadsharing reasonably well, and thus it is (in practice) an adequately safe arrangement.