Questions tagged [mwbc]

Use this tag for questions about Multi-Wire Branch Circuits, sometimes called "Edison circuits".

0
votes
1answer
60 views

Microwave on 220 volt branch

A friend has a microwave on the same circuit as electric stove. Independently they work fine but if an element on the stove is on and the microwave is turned on the breaker goes off. An electrician ...
2
votes
2answers
54 views

Understanding the wiring of 2-Pole Quad Circuit Breakers

I only want to understand the concept, so you dont have to address if my panel accepts tandem breakers or a certain brand of breakers. I will also omit any reference to ground wires for clarity. I ...
4
votes
1answer
155 views

Why are tandem breakers on shared neutral (MWBC) problematic?

I hear that shared-neutral or multi-wire branch circuits (MWBC) can have issues when used with tandem breakers (also called duplex, twin, cheater or double-stuff breakers). What is the issue there? ...
0
votes
3answers
77 views

2 breakers - should they work as one?

I have a circuit with 2 15 amp breakers. They don’t act, individually they both have to be shut off to shut off the circuits. Am I looking for an outlet with two devices? Example switch and outlet? ...
1
vote
1answer
80 views

Can I use a two-pole single handle breaker for mwbc?

I have a mwbc with two 20A breakers with their handles clipped for common trip. Can I replace this ensemble with a single two-pole 20A breaker with just one handle? New panel in CA. I'm unsure ...
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votes
2answers
272 views

Best way to get both 120V and 220V from existing multiwire branch circuit (MWBC)

I have a double pole 20A breaker feeding a 120V MWBC with 12/3 with ground, romex that goes up three levels to two separate 120V duplex GFCI receptacles with common neutral. I want to have both 120V ...
4
votes
2answers
229 views

MWBC (Multi-Wire-Branched-Circuit) w/out joined breakers, how best to fix?

I was trying to replace a fan/light in my living room with a new led light, and have found that the living room branch circuit (lights and outlets) is actually fed by a Multi Wire Branch Circuit (14-3)...
5
votes
2answers
832 views

Change from 240V to 120V

I did quite a bit of research including on this forum but wanted to double check if I got things right. On the outside of our home there is a standard electrical box (guessing about 3"x5") to install ...
1
vote
1answer
39 views

MBWC using two twin breakers with middle handles tied

My question is whether overload protection will work for the two handle tied circuits described below: Four separate circuits are involved. These are in a residence, feeding outlets and lights, ...
0
votes
2answers
93 views

Separate Phases for Residential Wiring

I am trying to find out if I can use a 14/3 cable to power two separate circuits, and to do that I know I must use two separate phases, but I am not sure how to do that.
2
votes
1answer
249 views

120/240 Multi wire branch circuit - failed inspection because of uneven loads?

From a double pole 20-amp breaker, I ran 12/3 w/g to a quad box with a 120 receptacle and a 240 receptacle. Red wire from one pole of the breaker to the 240, ground to the grounds, white to neutral ...
3
votes
2answers
387 views

Could the black and white wires in a three-wire cable both be used as hots?

In my detached garage, there is a ??/3 cable (haven't measured to know the gauge, though I'm thinking it's 10..) coming into a fuse box with two circuits. The strange thing is, the third conductor is ...
5
votes
2answers
185 views

Can I use a ground rod as an equipment ground for a detached garage?

I'm in a bit of a dilemma. The house we bought has a detached garage supplied by 12/3 UF with ground. The previous owner/handyman set this up as a multiwire branch circuit (MWBC) with a twist: one ...
1
vote
2answers
112 views

Requesting Evaluation of Power Plan at Rural Cabin

What I am looking for is guidance and honest evaluation. I'm not afraid of being wrong. I want to save some bucks and learn some things, without blowing myself up. So please tell me if I'm doing ...
1
vote
1answer
1k views

Multi-Wire Branched Circuit and GFCI

Forgive me if this a repeat, but I'd like to be sure I know exactly what's going on. I am installing 2 bathroom fan/light fixtures directly over the tub in 2 adjacent bathrooms on the same circuit. ...
18
votes
2answers
4k views

What is a tandem breaker (aka duplex, cheater, twin, double-stuff, etc.)?

I keep hearing about tandem breakers, and how they won't work with 240V loads and how they should never be used for a multi-wire branch circuit. Aside from those issues... What is a tandem breaker? ...
3
votes
2answers
61 views

Using a 1-pole GFCI to test half a multi-wire branch circuit

I'm searching my electrical system for defects, fixing the last guy's work. He loved to cross neutrals (grab a hot from circuit 5 and neutral from circuit 19). I've found several instances, but it's ...