I am wiring my soon-to-be-finished-basement with can lights and have decided to set up three lighting zones, each controlled by it's own dimmer switch. The plan was to put all three switches in the same gang box at the entrance to the room. The problem is that because the switches take up so much room, there's hardly any space left for the pigtails and wire nuts.

Here is my proposed solution. Install a second gang box adjacent to the switches but reversed allowing access from the closet behind. Bring the power into that second box and pigtail it there, then run the wires into the original 3-gang for hook-up.

Does that make sense or is there another solution that is preferable?

 

YOu may do what you are suggesting as long as there is sheathed cables covering all conductors that are not contained in the boxes. YOu must not install single conductors from box to box unprotected.

One concern that you should consider is that these dimmers create heat. Three dimmers in the same box creates a lot of heat also heating each other. This excess heat created by association often drastically lessens the life expectancy of each dimmer due to that excess heat. You might want to install separate boxes to inhance cooling containing a dimmer in each box. Also make sure the dimmers are rated in watts capable of controlling the load of the light fixtures each dimmer is controlling.

Good Luck

Wg

 

If I use 12-2 Romex to go from box to box and leave the shealthing on, is that sufficient?

As for heat, I had considered the affect on wattage and know that I'll need to break off some "fins" and that will reduce their capacity. But I hadn't thought of the actual degredation of the switches.

Would putting the three switches in a four-gang be better? Or possibly putting two switches in the three-gang box? If I install one dimmer per box, how could I install them so they'd be next to each other on the wall?

I appreciate your advice for in as much as I'm going for a clean professional and logical design, the dimmers aren't cheap and I'd certainly like to maximize their life expectancy.

 

I took for granted you were using 600 watt residential dimmers. If you have cooling fins I am suggesting you are using 1000 watt or larger dimmers. The cooling fins have a break off point allowing the fins to be sized as required to fit the multiple dimmers in the same box. If you have the cooling fins then you should be able to experience normal life. The cooling fins are designed for multiple dimmers in the same box.

As long as you make your junctions and make up in the adjoining box and you have cable sheathing protecting the single conductors between boxes. The make up in the adjoining box will allow only switch legs in that multiple dimmer box allowing for better cooling.

I see no Code violations in your design even using a single box to contain all the dimmers that have cooling fins with the make up connections in the adjoining box.

Good Luck

Wg

 

WG: allow me to complicate the issue a bit...

According to the directions, when multiple dimmers are installed together, the fins on the sides-in-common are supposed to be removed. Each set of fins removed lowers the rating by 20% or so. The plan was to have a 600W on either side with one fin set removed, to run at 500W and a 1000W in the center with both fins removed, thus running at 650W.

I've made sure that each run of lights will not overload the dimmers.

Based on this revised info, what are your thoughts about the heat level in the box?

Thanks again.

 

Although you are removing part of the fin you are also joining in close proximity and touching to the adjascent set of fins of hte neighbor dimmer. The 20% reduction you speak of is affected to the good by that close proximity. Almost like never having removed the fin. Running all the dimmers together at the same time the affects the cooling about 10% toward the bad again. I would not worry about the fins missing parts due to the adjascent fins aiding in the cooling process. In a dwelling general lighting is considered as intermittant you may load up to 100% by the NEC. If you are pulling less than 700 watts per dimmer on a 1000 watt dimmer then you should have no problem.

Wg

 

I'd at least consider installing multiple single-gang boxes in the same area instead of the 3-gang box.

 

Since the individual gang-boxes are installed by nailing them into a stud, and a vertical alignment of the switches is not preferred (in fact it would look pretty weird), can you recommend any installtion ideas to set three single boxes side by side?

If you thought it would help, I suppose at a minimum I could install two of the switches together in the three-gang box and put the third switch on a different wall.

As I said earlier, I'm struggling to weigh form over function.

 

Check this out:

http://www.erico.com/erico_public/pr...ntngBrckts.asp

 

Thanks mike.

based on that design, what does code say about building my own template to span the stud cavity. Say out of 1/4 ply?

 

There are unlimited ways to mount three single-gang boxes side by side. I'd probably just cut a few more 2x4s and frame up something between the studs.

 

If you are working with an open stud framing at this time I would just be a couple of more studs and toe nail them into the wall frame then treating each box mounted on each stud normally.

Just a suggestion

Wg

 

Bringing an OLD thread back from the dead... I know...

I want to let folks know how helpful this was. I've been trying to work out a solution similar to this for a while now and just can't seem to get it right. I can get it electrically correct but the physical install of the wiring/devices has escaped me until now. I even had the wall closed in, mudded, primed, painted, and had to rip out a sheet of drywall to remediate the dimmers because they would not screw down without losing a connection.

Sometimes it's the simple things. With the framing opened back up all I needed was the suggestion to add another framing member or two so I could put in multiple single boxes instead of two deep dimmers in one box. The wires were just too crowded in the dual gang box. I'm adding a bit to the framing now so I can put in multiple single boxes and that should do the trick just fine. Why the hell hadn't I thought of this before?

 

Regarding the original post I would have used a five-gang box (may need to build it out of gangable metal boxes) leaving an empty gang between dimmers. To simply gain more space for connections you could use more gangs or you could install another box of suitable size connected to the switch box with a PVC nipple. The second box would contain most of the connections with only the wires need for the switches or dimmers going to that box via the PVC nipple.

I did this on the stub wall next to my refrigerator and the connection box is almost invisible with the refrigerator in place.