Well, I've seen more than a few threads of telecom man vs. sparkie man, so I thought I'd throw a question out to reverse the situation a bit.
After 8 years, I'm finally finishing my basement. I've run out of 12/2, but have plenty of 12/3.
I need to run 2 more circuits from the panel.
One of the circuits will only have 1 receptacle on it (for a mini fridge).
The other circuit will have 4 outlets on it.
What I'm wondering is - although code (NEC 201.4) apparently permits it - can I run 12/3 from the panel and use the neutral as common for both circuits (multiwire branch circuit)?
Code says yes, as long as I provide a device (yoke) to trip both breakers if either of them trips. As far as I can tell, this requirement is to protect people working on the circuit later, thinking it's deenergized when it's not.
But I don't understand why something like this would be legal. It seems to me the neutral will be carrying the load of both circuits, and since the neutral doesn't have overcurrent protection, would be subject to overheating. On the other hand, a circuit is a circuit so I suppose the breaker would trip if either circuit were overloaded, regardless of the fact that they share a neutral.
So, I'm torn between having 175' of unused 12/3; probably never to be used again, or going up and buying another 75' of 12/2.
So the question. If it were your house, would you:
1) Go buy some more 12/2.
2) Use a multiwire branch circuit.
3) Use the 12/3 to feed the 2 circuits, but leave the 3rd (red) conductor unused (i.e. make the 2 runs with seperate 12/3 runs).
Any thought/opinions appreciated!
- Matt
