2-pole breaker instead of two 1-pole breakers?

[Jason White]

Can I use a double-pole breaker to feed two 110-volt circuits instead of a single 220-volt circuit? Is that legal?

It's a new Murray breaker with a removable "tab" between the two switches. Also, the breaker says 110/220 on it.

[Mike Henderson]

I don't know the code, but electrically it will work. If you remove the tab that ties the two switches together it should act like two 120V breakers.

But why do you want to use that instead of two breakers? Is it that you have that breaker on hand and would have to buy two separate breakers?

Mike

[Leo Graywacz]

Standard practice around here for the receptacle under the sink that powers the disposal and dishwasher.

[Jason White]

That is correct. I know it works, because I already have it installed that way. I just want to know if it's legal per code.



I don't know the code, but electrically it will work. If you remove the tab that ties the two switches together it should act like two 120V breakers.

But why do you want to use that instead of two breakers? Is it that you have that breaker on hand and would have to buy two separate breakers?

Mike

[Steve Peterson]

Standard practice around here for the receptacle under the sink that powers the disposal and dishwasher.

A double breaker in this case would force the two circuits to be on separate polarities. The wiring could use 12/3 without overloading the neutral. If the breakers were accidentally connected to the same polarity, then you could have 20A on each hot wire and 40A on the shared neutral. A double breaker would not allow more than 20A on the neutral.

Jason's situation is slightly different. Removing the tab makes the double breaker act like two completely independent breakers. I believe that if you remove the connecting rivets, then they would be truly independent 110V breakers.

Steve

[Prashun Patel]

I've had multiple contractors say it's totally fine, and my box was wired that way (unpermitted basement finishing) for a couple years with no ill-effects. However, when I subsequently had some permitted work done, the inspector flagged me for it, and I was forced to go with separate breakers. So, you should check with your township.

[Bruce Wrenn]

First, it's called Multi-wire branch circuits. Second, the service from the power meter to your panel is done this way. That is why the neutral is permitted to be a smaller size than hots. Third, because the two 120's share a neutral doesn't mean the neutral carries any more than 20 amps that either of the hots carry. The two hots cancel each other out as far as the neutral is concerned. My shop circuits are wired this way. At each location, have 2-20amp 120V and one 20 amp 240 volt outlets. The hot to one of the 120's which also feeds 240 outlet passes thru sensor for controlling DC. This means one recpt. and the 240 recpt operate the DC.

[Anthony Whitesell]

Can I use a double-pole breaker to feed two 110-volt circuits instead of a single 220-volt circuit? Is that legal?

It's a new Murray breaker with a removable "tab" between the two switches. Also, the breaker says 110/220 on it.

One would be lead to assume that you don't need the circuit to be GFCI or AFCI as those are not available in the two pole breakers.

One item I think that is missing from the discussions is the wire used. Jason, are you proposing to pull two 12/2 cables or one 12/3?

If you pull two 12/2 cables, then you have nothing more than two single breakers, that when one trips the other will trip without a fault on that circuit. Really no big deal except for the fact you may not know which tripped.

If you run one 12/3, there would be contention the neutral is undersized as there exist two 12g wires feeding two separate loads. Many items that require 120 and 240, mainly require the 240V and the load on 120V is for control and is negligible. Additionally, items that require 120V and 240V usually only pull 120V from one leg. For example, an oven requires 120V and 240V; one of the hot legs runs a few amps higher than the other (my oven has a 1A fuse on the 120V circuit) and there same amperage difference appears in the neutral as one would expect. 240V doesn't use the neutral but the 120V does.

[Jason White]

Two completely separate circuits, each with its own neutral and ground.

Again, it works. I just want to know if it's legal.




One would be lead to assume that you don't need the circuit to be GFCI or AFCI as those are not available in the two pole breakers.

One item I think that is missing from the discussions is the wire used. Jason, are you proposing to pull two 12/2 cables or one 12/3?

If you pull two 12/2 cables, then you have nothing more than two single breakers, that when one trips the other will trip without a fault on that circuit. Really no big deal except for the fact you may not know which tripped.

If you run one 12/3, there would be contention the neutral is undersized as there exist two 12g wires feeding two separate loads. Many items that require 120 and 240, mainly require the 240V and the load on 120V is for control and is negligible. Additionally, items that require 120V and 240V usually only pull 120V from one leg. For example, an oven requires 120V and 240V; one of the hot legs runs a few amps higher than the other (my oven has a 1A fuse on the 120V circuit) and there same amperage difference appears in the neutral as one would expect. 240V doesn't use the neutral but the 120V does.

[Allan Speers]

Why?

It will work, but I see absolutely no up side.

[Wade Lippman]

I've had multiple contractors say it's totally fine, and my box was wired that way (unpermitted basement finishing) for a couple years with no ill-effects. However, when I subsequently had some permitted work done, the inspector flagged me for it, and I was forced to go with separate breakers. So, you should check with your township.
Why? Doesn't violate any code I am aware of.