Gfci Breaker


Old 12-09-04, 06:25 PM
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Gfci Breaker

I have a different situation here... Ran 12/3 with g. for two seperate 20 amp circuits, sharing the nuetral.. They need to be gfci protected. With only the one nuetral for both circuits, if I pigtail the nuetral in the box, then run one to each of the gfci breakers will they trip individually if I put each breaker on a different bus bar like normally to isolate each circuit or will they both trip if a ground fault occurs? any other solutions,,,, than the obvious of just using gfci receptacle of course... would like to use these breakers but never came across this situation.... help is appreciated!!!
Old 12-09-04, 06:35 PM
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Multi-wire circuits cannot be placed on GFCI breakers they will trip.GFCIs {receptacle & breakers} are designed to sense an imbalance in the current going from the hot to the neutral which should be equal in a normal situation.If you have a shared neutral circuit ther will be a difference in current between one hot and neutral & the other hot and neutral,thus causing the breaker to open the circuit.The only solution is to install a GFCI receptacle at the earliest point on each individual circuit.
Old 12-09-04, 06:48 PM
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On your multi wire circuit you will need two GFCI receptacles, and there cannot be a common neutral after those GFCIs. Everything after the GFCIs must remain as two separate circuits.
Old 12-09-04, 07:23 PM
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Multiwire circuits and GFCI make uneasy bedfellows. It's just one of the many reasons I think most people should stay away from multiwire circuits except in limited situations. Here are your options:
  1. Abandon the mutiwire circuit and run two 12/2 cables instead of one 12/3 cable. Put a GFCI in the first box on each 12/2. This is simplest, cheapest, and my recommended solution.
  2. Use the 12/3 up to the first box only. At the first box, split the 12/3 into two runs of 12/2. Put a GFCI receptacle at the head of each 12/2. This is the solution that Bob was suggesting. There will be no shared neutral after the first box.
  3. Buy an expensive and hard-to-find double-pole 20-amp 120/240 GFCI breaker. This will work perfectly, but it isn't cheap. No GFCI receptacles will be needed, and you can share the neutral all the way.
  4. Use a GFCI receptacle at every outlet. There will be no downstream protection, and nothing will be connected to the "load" side of any GFCI. This solution may not be too bad if there aren't many outlets.
Old 12-09-04, 07:57 PM
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Gfci Breaker

Thanks for the reply's ,,, all answers make sense, not sure witch one I'll go with, two 12-2's sounds most practical, don't know what I was thinking, I'll just take the breakers back, don't use them that often... had a brain fart I guess.... thanks!!!!

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