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Discussion Starter · #1 ·
I installed a spacer system a few months back. I have a 4 gang box with 3 dimmers and a master controller.


The dimmers are installed as such:


Dimmer 1 | Dimmer 2 | Dimmer 3 | Master

SBS-1000 | SBS-600 | SBS 1000 |



Dimmer 1 is running 8 Recessed Cans with 75watt bulbs and is the one that is getting hot. According to the Lutron people, being in a 4 gang box and only removing the tabs from the right side should only downgrade the box a little.


Is it typical that these dimmers got hot? When I saw hot, I mean if I put my finger on the aluminum tabs, I can only keep it there for a few seconds before it burns.


Should I be concerned with this? I haven't put the dryall on this wall yet and still have access to easily get to the box etc.



THanks,


Jeff
 

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Jeff, do you have the ability to load another one of the circuits down to 600W to see if that dimmer gets just as hot as Dimmer 1? Alternatively, if you remove some bulbs from Dimmer 1 to match another dimmer's load, do they get equally as hot?


- Chris
 

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Discussion Starter · #3 ·
At this point, I can load the other 1000 switch as it is for my rope lighting which I haven't purchased yet.


I can try and remove some of the bulbs on dimmer 1 and see if it has the same effect.


When I only have 600 watts on the 1000. So I think that should be able to handle it even with the downgrade. I'll have to call Lutron and touch base as well.
 

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Jeff, generally speaking, when one places dimmers in multiples, the must be derated, because the heat sources slow heat dissipation. Two 600-watters must be derated to 500 watts each, three or more, to 400 watt each. With the 1000's, a safe bet would be to use the same ratios, would be 833 and 667 under the same conditions.


Heat is normal, especially around 1/2 to 2/3 settings. Modern electronics are capable of running at hotter temps than in the past, but the fact that heat shortens life still holds true. Your dimmer #1 has (8 x 75) 600 watts on it, which is certainly within safe limits. You could try swapping the other 1000 for comparison.


What are the loads on the other two dimmers? That matters, too. You may have noticed that commercial dimmers have finned heat sinks for front plates, which helps dissipate a lot of heat. If your 4-gang box is plastic, try replacing it with a metal box, either gangable or a single formed box.


There are electrical boxes that are larger than the four gangs, and a four-gang plaster ring is installed on it. This would allow for more air space inside the box, as would drilling a dozen or so holes in the top and bottom of the box. You might even try this with the existing box. I would stay with 1/4" holes or smaller.
 

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I found the spec sheet. (PM me if you would like me to send it to you)


If you remove one fin (tab), the 600W dimmer is derated to 500W. Remove both fins and it is derated to 400W.


For the 1000W dimmer, removing one fin derates it to 800W. Removing both fins and it'll only handle 650W.


--Burke
 

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Well, my estimates were pretty close. Rounding them down gives the same numbers. Also, ganging the dimmers requires removing the tabs.
 

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Discussion Starter · #7 ·
So I am just below the 650 limit. I could put in some lower watt bulbs later on.


Thanks for the input. When I ordered the switch I told Lutron what I would have on each dimmer and they said that should be fine, even with ganging them. I just never realized that they would get so hot.
 

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Jeff, use halogen bulbs; you get a brighter, whiter light for fewer watts.
 
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