dimmers

[JJWalecka]

I am under the impression that an individual box is required for a dimmer. If you ganged a dimmer and a switch you had to derate because the dimmer has a resistor. The logic seems sound but is that required? Anyfeedback is always welcome.

JJ

 

[Dennis Alwon]

I am under the impression that an individual box is required for a dimmer. If you ganged a dimmer and a switch you had to derate because the dimmer has a resistor. The logic seems sound but is that required? Anyfeedback is always welcome.

JJ

Lutron Rocker style dimmers have fins that should be removed to have the dimmer fit properly in the box. The removal of fins causes the derating because it cannot dissipate the heat as easily.

 

[JJWalecka]

Dennis Alwon thank you. So if you left the dimmer intact it would dissipate the heat propoerly? Can you gang several devices without removal of the fins?

JJ

 

[resistance]

I agee!

Wow Dennis, you have reached 7666 post.

 

[480sparky]

Dennis Alwon thank you. So if you left the dimmer intact it would dissipate the heat propoerly? Can you gang several devices without removal of the fins?

JJ

Depends on the dimmer. Some 1000watt dimmers you can, other need a 2-g box no matter what.

 

[JJWalecka]

"Only you will see your way to the top, but you must apply yourself to get there!" Nice Quote Resistance.
"Something for nothing, is worth just that, Nothing" Quote from my Father

JJ

 

[JJWalecka]

Thank you very much for your time. I appreciate your feedback

JJ

 

[resistance]

"Only you will see your way to the top, but you must apply yourself to get there!" Nice Quote Resistance.
"Something for nothing, is worth just that, Nothing" Quote from my Father

JJ

Thanks! I made it up myself. Yet, I'm sure someone has said it somewhere

 

[LarryFine]

If you ganged a dimmer and a switch you had to derate because the dimmer has a resistor.

Actually, a dimmer 'has' resistors, but the heat comes from a special type of power transistor called a Triac. You have to derate for multiple dimmers for two reasons:

1. Because the cooling fins would overlap if two dimmers are placed side-by-side, and you need to snap them off if two are adjascent.

2. With side-by-side dimmers both emitting heat, each will cool more slowly, and the more, and the less finning, the more heat.


You can compensate for derating by using a higher-rated dimmer. For example, a typical 600w dimmer must be derated to 500w if two are adjascent, and to 400w for three or more. If you step up to a 1000w dimmer, two might be useable at 800 or 850, and three or more at 600-700w.

 

[peter d]

If you are going to gang dimmers, then you should use the deepest box possible for your particular application. If using NM/plastic boxes you will have to pay a premium for deep multi-gang boxes but they are well worth it.

Hopefully the above information is as obvious as "Water is wet" but you never know.

 

[resistance]

but they are well worth it

I couldn't agree more!!!

 

[alfiesauce]

I've been able to place a lutron dimmer next to a decora non-dimming switch in a 2-gang without having to derate the dimmer (break the tabs off)
LarryFine's statement about upping the size of dimmer to get higher values after deration is definatley worth keeping up your sleeve.
Regardless of deration, heavy loads on dimmers causes heat and some home owners freak out about the screws on the cover being warm to the touch, so now I try to always inform them about this being normal before I leave a final.

 

[JJWalecka]

Thank you everyone!

JJ

 

[Dennis Alwon]

I've been able to place a lutron dimmer next to a decora non-dimming switch in a 2-gang without having to derate the dimmer (break the tabs off)

Sure you can get them in without breaking the fins but I think the instructions still say if you gang them together you must derate. Apparently the heat can cause damage to the unit when 2 dimmers are side by side.

 

[LarryFine]

Dennis, read the quote you quoted again.

 

[electricmanscott]

Hopefully the above information is as obvious as "Water is wet" but you never know.

This would not be obvious to some of the people here. They could find a reason to argue against it.

 

[cloudymacleod]

Dennis Alwon thank you. So if you left the dimmer intact it would dissipate the heat propoerly? Can you gang several devices without removal of the fins?

JJ

with most dimmers, u can use a reg switch and dimmer without removing the fins. the problem arises, if you multiple dimmers in a gangable box, then u might have to remove fins. but remeber, when you removing fins you losing the wattage for that typical dimmer. for example, i think with lutron dimmers, if you remove one side of the fins u lose 100w, so a 600 watt dimmer turns into a 500w dimmer, with all the tabs removed it turns into 400 watt dimmer. to dispate heat from a multiple dimmer box, some use metal switch plates.

 

[JJWalecka]

cloudymacleod thank you!

JJ

 

[alfiesauce]

you are indeed correct cloudymacleod-son.