combo switch wiring

Is it possible to wire a combination switch from a single light switch?

 

Are you talking about a double switch (one over the other)? Exactly what kind of function are you wanting to do?.....RL

 

As RL says, tell us whether you are talking about a duplex switch (two switches), or a switch/receptacle combo.

Then tell us the colors of the wires attached to the existing switch.

If you are installing a duplex switch, or if one of the wires connected to the existing switch is white, then you'll need more wiring in the walls to accomplish what you want.

Please provide more information.

 

Hey,

I did a search of this forum & ran across this question. I have the same question - only I'll reply w/ more detail!

In my case, there is a combo switch in the basement, it's a Leviton, it has a hot & netural on the left side, with what looks like to hot on the right. The top is an on/off switch, the bottom a receptacle. Anyhow, there was a single electrical cable coming to it, it was wired with a hot & netural on the left side, the right side had the tab broken with no wiring. The previous owner used the on/off to power the bottom receptacle.

I want to modify this if I can, I'd like the switch to control both the receptacle and a light. I installed a light on the line leading to this switch, so before the line came directly from another receptacle. Now there is a light between them. This combo switch is the end of the line for the circuit.

Can I do this somehow? Or do I need two lines coming in? Can't seem to figure it out, I'm not sure how or If I can use this to control two devices: the bottom receptacle and a light (the cable in comes from that light).
Thanks,
Bob

 

The project is easy, but not the way you tried to do it. You can't simply put the light on the line to this box. Here are two options to recover:[list=1][*]Put it all back the way it was before. Then run a new 14/2 cable from the box containing the combo switch/receptacle to the new light.[*]Leave it as is, but replace the 14/2 cable from the light to the combo with a 14/3.[/list=1]Tell us which course of action you choose, and we'll provide details.

 

Hey John,

Actually, I realized it wouldn't work the way I tried, so before reading your post, here's what I did:

The original combo was coming from a junction box. I realized that putting a light in between wouldn't do it so I went to the box and put the light off the box. So that box now has the feed in, an out to some other outlets, an out to the combo and an out to the light. I wired it correctly, everything works, including the light when I use a standard on/off switch. However when I use the combo switch, the receptacle is 'live', but the switch doesn't power the light.

Make sense?

Many thanks!
Bob

 

You confused me a bit. You refer to a "standard on/off switch", but where did that come into the picture? Where is this switch?

If I understood you correctly, you still don't have the cable you need to control the light with the switch on the combo. As I said before, you either need to run 14/3 to the combo device, or you need to run 14/2 from the combo to the light you want it control (or you need to give up the receptacle on the combo).

 

Sorry for the confusion. The standard switch I refer to is one that I put in instead of the combo switch. In other words, I wired the standard switch instead of the combo to test it, that worked fine. Then when I take the standard switch out & replace it w/ the combo, the light isn't powered.

Sounds like I need to get a run of 14/3, I'm running 14/2. I've purchased cable in 100' runs before, do you know if a typical home center sells it in shorter runs? Also, the tab between the right side terminals was cut, should that make a difference?

Thanks for the help, John, between this and other postings you replied to, I'm well on the way to rewiring a few basement rooms!

Bob

PS - an unrelated question, something that I can investigate - but if you have a quick answer, that would be great. Old house-a few overloaded circuits, especially in the kitchen. I found out that the garbage disposal is on it's own circuit - is that necessary? If not, it would be easy to spread some of the load onto this.

 

Replace the cable between the junction box and the combo box with 14/3 (12/3 if this is a 20-amp circuit). Not sure what lengths the home center sells it in. You might be able to get a 25-foot roll. The black wire will carry unswitched power to the combo. The white wire will take the neutral there. The red wire will carry switched power back. You can then connect the red wire to the black wire going to the light.

Is that separate circuit for the disposal a 15-amp or 20-amp circuit? How many horsepower is the disposal? Depending on your answers, it might be possible to add more loads to the disposal circuit. But, and here's the rub, those additional loads cannot be receptacle serving the countertop.

 

Thanks John, I'll get some 12/3, as the breaker is 20 amp.

The disposal is on a 20 amp circuit. Not sure of it's horsepower, it actually isn't too effective and I'll be putting in a new one in the next several months. Is the rule about serving countertops deal specifically with the disposal or is it any countertop receptacle cannot have any other device on it?

Bob

 

The kitchen small-appliance circuit rules are complicated. To give you a rough summary, a circuit serving the kitchen countertop can serve receptacles in a dining room, the refrigerator, a clock, and accessories to a gas stove. Nothing else. I realize that many older homes violate this modern rule. While these homes need not be brought into compliance, it is not allowed to take them further out of compliance either.

You should be able to add more loads to the disposal circuit. If your dishwasher is also on its own 20-amp circuit, you could combine the dishwasher and disposal on one circuit, and using the other 20-amp circuit for more kitchen receptacles.

Seems strange to me that the disposal has its own 20-amp circuit, but the kitchen is otherwise underpowered. Perhaps the kitchen was partially remodeled at some time in the past.

 

Lots of weird wiring. The house was built in the early 50's (like me!) and I think the disposal was added many years later. Probably easiest for them just to run a dedicated run. I may do a little re-distribution now, however we're planning on a major kitchen overhaul in the coming years & everything will be redone.

Thanks again - 1/2 of my workshop now has 4 times the outlets, soon it will be completely re-wired!

 

John - I hope I'm not being too much of a pest! Just had a thought - I was thinking of getting a long, multi-outlet powerstrip for one side of the workshop - I could put a 6' strip w/ 8 or 10 outlets above my workbench. I would never use more than 1 or 2 at a time, but it sure would be convenient! The question is if my room is wired w/ 20 amp romex, can a surface wire unit like I'm talking about be 15 amp? I seem to recall that it should be the same, but I can't recall.

Thanks,
Bob

 

Yea, it's okay. You can put a 15-amp power strip on a 20-amp circuit. However, you might instead consider adding more permanent receptacles to the circuit. It would be a better solution.

 

John - when I do this wiring, I assume that the box needs to be accessible upon completion, right? The box is currently between joists (was there previously), when I drywall, I imagine code would require access.
Thanks,
Bob

 

All junction boxes must be permanently accessible. This means no drywall covering them. They also cannot be hidden under insulation either, in the attic or crawl space for example.

 

Thanks, that's what I figured!