I am In Ontario Canada. I am doing a renovation and I came to a switch box for my hallway that has two three way switches that operate two diffent lights. One at the top of the stairs and one at the bottom. There is also a regular switch for an out side light.

When I opened the box I noticed that the power in for the outside light and the downstairs 3way comes from one cicuit breaker and the upstairs 3way comes from another circuit breaker.

The power for the upstairs light comes into the upstairs 3way switch and down to midfloor gang switch so I cannot easily convert the switches to all be powered from the mani switch box.(Picture 1).This is how it is wired This is the actual switch box What I want to know if this is ok to do. I have seen it done in to ganged switch boxes in the house. I am doing other work and will be getting an electrical inspection so want to make sure it is proper. Thanks in advance. I noticed that it does not meet current code re the nuetral, but the house is 35 yrs old so that part was code back then so I dont think I have to change or rewire the whole house.

  • 1
    You can, but the problem is when someone does work in that box and does not know of the second circuit breaker. It is better if you can use a handle tie on the two, so turn off one the other one is turned off also.
    – crip659
    Commented Apr 20, 2023 at 0:18
  • Can I bind the regulare breaker I have or do I have to by ones that are manufactured that way?
    – Bmac
    Commented Apr 20, 2023 at 1:16
  • 1
    With most breakers there are handle ties available for a few dollars from the manufacturer. What you can't do is just stick a nail in there. Commented Apr 20, 2023 at 2:36

2 Answers 2


This is legal, but likely to cause confusion for the next person. As such, it would be wise to use gray tape or shrink tube over the neutral wires for the 2nd circuit, so they understand it should not be combined with neutrals for the first circuit. Unfortunately a lot of people think all neutrals should always be combined (no; however that is true for safety ground.)

Code has no requirement for a handle-tie here.


This is perfectly fine. Based on the age, not having neutral in all switch boxes is OK. Having two separate breakers involved in one box is also OK, though it can be confusing. The one really critical thing is to not cross neutrals between circuits, but based on the diagram that is not an issue here.

As far as the two breakers for one box, due to the 3-way switches involved there is no easy fix inside the box. But if you think outside the box (pun intended), you could actually solve this problem in the breaker panel. Assuming the two circuits are general lighting/receptacle circuits, you can disconnect the hots from the two breakers, combine them together with a wire nut and a pigtail that you then connect to one of the breakers. That frees up the other breaker for another circuit. I don't know if it is required by code, but it may make sense to join the neutrals in the same way to help avoid future confusion in the breaker panel. Due to the far lower power requirements of modern LED lighting compared to the incandescent lights of just a few years ago, there should not be any overload concerns with merging the two circuits.

  • 1
    Outside of the box is a great idea and works perfectly for me! The pannel was upgraded in 1991 and most of the wires were too short and I had to add five juncion boxes beside the panel to add length.... Since this is a major rewire It is easy for me to combine two circuits outside the panel and still keep it clean and neat. Great suggestion! I will be be able to consolidate a couple circuits and free up a few breakers for the new renovation. Thanks.
    – Bmac
    Commented Apr 20, 2023 at 2:33

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