DIY Home Improvement Forum banner

1 - 20 of 21 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
Hello I was writing because I am in the process of rewiring my personal duplex which caught on fire and ran into a little issue. In the shared hallway there is one light fixture and two switches for it. One for each unit. What I was wondering is how to rewire this light with the two circuits . I come from an industrial electrical background and do not know all the little tricks like this.
 

·
Registered
Joined
·
1,646 Posts
add another light so there is one powered from each unit. ive seen that many times over the years. or is this on the house meter or wired into one unit?
 

·
Registered
Joined
·
9,288 Posts
You may not have two (different) circuits powering the same light bulb.

You can make the two switch locations into a 3 way switch setup, power from one circuit to one switch, 3 wire cable between the switches, 2 wire cable to the light. This works best with a separately metered common area circuit.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #4
Yes I understand I could hook it up to a three way switch but these to were right beside each other and switch said unit 1 the other said unit 2. So this is why I believe there were two separate circuits.
 

·
Semi-Pro Electro-Geek
Joined
·
3,403 Posts
Yes I understand I could hook it up to a three way switch but these to were right beside each other and switch said unit 1 the other said unit 2. So this is why I believe there were two separate circuits.
Did they operate as three-way switches? In other words, if the light was on, could you turn it off by flipping either switch? If so, then it is one circuit. Or, does the light come on any time either switch is on, and both switches must be off to turn the light off? If that's the case, then you could have two circuits feeding it. It is not code compliant or safe to have two circuits feed it. If that's how it's wired, it should be changed. Such an arrangement would allow either panel to be backfed by the other panel even when the main breaker is turned off. That's dangerous.
 

·
Registered
Joined
·
5,468 Posts
One way to do it is-
Wire the centre toggle of the switch to the lamp (hot).
Then one of the positions to unit 1 supply.
The other position goes to unit 2 supply.
This would work BUT I dont think the regulations would approve
as there are some risks involved.

So if for interests sake you just like to know how it could be done,
Then this is how.
But carefully check the regulations in your area before you consider
doing this.
As my guess is it is not permitted.
 

·
Registered
Joined
·
1,190 Posts
I come from an industrial electrical background and do not know all the little tricks like this.
The many industrial sparkies I have known in my carreer tower above residential electricians in knowledge

Not even close

Barely the same trade

Kind of like a major League ballplayer and the guy who rakes the infield
 

·
Registered
Joined
·
5 Posts
Discussion Starter #8
Yes I figured this was not a legal hook-up the unit is very old and has a few things which are not of code. Yes I have been doing industrial my whole 7 year career in the trade and it is like night and day between the to. Not much comparison at all. Thank you all for your input.
 

·
Registered
Joined
·
9,288 Posts
One way to do it is-
Wire the centre toggle of the single pole double throw (e.g. 3 way) switch to the lamp (hot).
Then one of the positions to unit 1 supply.
The other position goes to unit 2 supply.
This would work ...
How do you turn the light off?

Note that a load may not receive a hot feed from one circuit and use the neutral of another circuit.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #12
Actually I am an electrician journeymen certified by the state and I also hold red cards from refineries so I was just wondering if there was something that I was missing there. I understand the electricity but I just dont role homes at all that's not wat I do. I actually touch things stronger then your little 120.
 

·
Registered
Joined
·
4,745 Posts
You aren't allowed to wire the light from two seperate circuits. One circuit with two three way switches is what you need to do in this situation. That being said, I have seen lights controlled from two places with regular single pole toggle switches on the same circuit. The problem with this is that both most be off to have the light off, while either switch on will turn the light on. A three way switch would make more sense in my opinion.
 

·
Registered
Joined
·
9,288 Posts
Hire an electrician, cause I don't know what you ...
That might not be necessary. All of us here already told him everything including that what he said he wants to do may not be done.
 

·
Registered
Joined
·
1,190 Posts
But you don't want to help him here?
I did help him, I told him to hire an real electrician. Anyone who claims to be an industrial electrician used to wiring high voltage systems, yet needs to ask rudimentary questions about wiring a switch in a residential application should be viewed with a highly jaundiced eye.

Given the dangers involved, the OP should hire an electrician capable of the job who does not need to consult anonymous strangers for "how to" questions as he proceeds
 

·
Registered
Joined
·
1,324 Posts
Given the dangers involved, the OP should hire an electrician capable of the job who does not need to consult anonymous strangers for "how to" questions as he proceeds
I guess this would be your reply to everyone who posts here? Why did you join this site, again?
 

·
Administrator
Joined
·
40,871 Posts
Hmmm, wonder if those switches aren't 4 way/traveler reverse switches.
 
1 - 20 of 21 Posts
Top