(2) 20/1 breakers fed from same 120V circuit
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LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
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- Electrical Contractor
A tandem breaker is merely two independent 1p breakers that happen to share the same bus stab.
Do two breakers share same neutral?
If they do there is a problem, they would be MWBC's and would need to be on separate legs. Each circuit would need to have it's own neutral. You could still use those breakers for MWBC's but you would have to be sure the MWBC's were on different legs and use handle ties for the two handles associated with them.
texie
Senior Member
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- Fort Collins, Colorado
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- Electrician, Contractor, Inspector
Absolutely not. As roger just stated, these are not intended for MWBCs as you would have double the current on the neutral.
Best to load each breaker max. 8 amp.?
No, you can load them as you would any breaker.
Much like the breaker they're using on circuits 11 and 13 if those 2 circuits should happens to incorporate a neutral.
Jap>
letgomywago
Senior Member
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- Washington state and Oregon coast
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- residential electrician
The old challenger little ones I might agree with you but it's the same bus stab as a 60 amp breaker has so there isn't anything different than a standard 20 amp breaker.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
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- Electrical Contractor
Two tandem breakers can be wired to share two neutrals, but only one tandem breaker can not share one.
To expand, that's something you must avoid doing. Here are a couple done correctly. Note that the blacks and the reds are not landed on the same breaker body. They must be wired as a 120/240v circuit.
This way, each neutral only sees difference current as it would in any standard multi-wire branch circuit.
Here are tandems that are done incorrectly. Note that there is a black and a red on each breaker body. That's the same as feeding a neutral-sharing pair of circuits from two breakers on the same phase.
Each tandem breaker could supply two 15 (or 20) amp loads and subject the shared neutral to 30 (or 40) amps if wired this way.
Note here the panel cover diagram. It literally shows what happens inside a tandem breaker; two independent breakers that share only the power pick-up point and the plastic case.
Here is a triplex tandem that allows adding a 2p circuit to a pair of 1p circuits, or adding a pair of 1p circuits to a 2p circuit.
Note that the 2p breaker must be in the middle to receive power from both buses. If it was at either end, it would only be able to supply 2x 120v, and not 240v.
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Or, If the handle tie was configured differently, you could also receive 240v power from the 2 "outside" 15 amp breakers in the picture.
It's not a "must" that the 2p configuration be located in the middle of a tandem breaker to receive power from both busses.
JAP?
AC\DC
Senior Member
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- Florence,Oregon,Lane
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we're the handle ties I the first image
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