Wafer breaker with multiwire circuit

[Bill Smith]

Multiwire circuit on a wafer (twin) breaker. Neutral showed no sign of overheating. Your thoughts?

[Brian A. MacNeish]

Originally Posted by bsmith

Multiwire circuit on a wafer (twin) breaker. Neutral showed no sign of overheating. Your thoughts?

If that double pole breaker serves a 14-3 or 12-3 wire and is supplied from the same buss, it may be a problem at the neutral at some future time when higher loads are imposed on it. Not correct!

With that arrangement, the load on the neutral is additive of the loads from the hots (eg. #14 AWG.......9 amps on each hot = 18 amps at neutral). When each breaker is served from a different buss, the load on the neutral is the difference of the two (9 and 11 amps on hots = 2 amps on neutral).

[Robert Meier]

The photo is inconclusive. Do you know that both of those conductors on that CB, the red and black, are from the same cable?

[Bill Smith]

Brian Thanks - that's what I was thinking.

Robert - Yes - I traced them back to the cable where it entered the panel. The neutral showed no signs of overheating, but I guess it is likely to in the future.

Thanks for your replies guys!

[Bruce A. King]

It's wrong but you will not see any overheating since the multiwire circuits are typically low current such as disposal/dishwasher or gas furnace airhandler/attic lights etc.

[Brian A. MacNeish]

Originally Posted by bking

It's wrong but you will not see any overheating since the multiwire circuits are typically low current such as disposal/dishwasher or gas furnace airhandler/attic lights etc.

14-3 is used for kitchen countertop split receptacles here; a neutral on one of these circuits could easily be overloaded if hots are fed from the same buss and a couple of heavier drawing small appliances are being used!!

[Bill Smith]

Good info - Thanks Bruce.

[Robert Meier]

Originally Posted by Brian A. MacNeish

14-3 is used for kitchen countertop split receptacles here; a neutral on one of these circuits could easily be overloaded if hots are fed from the same buss and a couple of heavier drawing small appliances are being used!!

#14 AWG conductors would not be permitted on a SABC servicing counter receptacles since that circuit would be required to be 20 amps.

[Bill Smith]

20 amps according to current codes, but this house was built in the 60's.

[Brian A. MacNeish]

Originally Posted by Robert Meier

#14 AWG conductors would not be permitted on a SABC servicing counter receptacles since that circuit would be required to be 20 amps.

What does this stand for?

[Stephen W. Stanczyk]

Small Appliance Branch Circuit

[Robert Meier]

Originally Posted by bsmith

20 amps according to current codes, but this house was built in the 60's.

Ahh, that makes more sense.

[Brian A. MacNeish]

Originally Posted by Robert Meier

Ahh, that makes more sense.

Does the NEC not allow 15A, (3 wire) split countertop receptacles or is it all 20A circuits to the kitchen. Here there can be a mix depending on proximity to the sink (need 20A GFCI protected receptacles within 5')

[Robert Meier]

All receptacles serving kitchen counter tops require GFCI protection regardless of their proximity to a sink. They also are required to be on 20 amp circuits when serving the counter top.

[Brian A. MacNeish]

Originally Posted by Robert Meier

All receptacles serving kitchen counter tops require GFCI protection regardless of their proximity to a sink.
I find this a bit curious as some countertop receptacles may not even be on the same side of the kitchen or on the same counter as the sink.


They also are required to be on 20 amp circuits when serving the counter top.

So from what I read.......... no more 15A, 3-wire split receptacles along countertops there now?