how many recessed lights on one switch or dimmer ?

[Stevenfyeager]

some dimmers are 600 W incandescent or 150 W LED rated. In a new house, its hard to know when the new owner will request a dimmer in place of a switch. The LED light trim kits I use are 9 or 10 watts each. So I put 12 can lights on one dimmer, (80 % of 150 W) But before LEDs, we could only put 7 lights. Most customers use LED, but what if they used incandescent ? Is there a NEC rule here? Do I need to assume incandescent to play it safe and only put 7 ? Thank you.

 

[LarryFine]

I'd say that, like most NEC rules, it's based on what is installed, not what could be installed.

To add, that is still a lot of lights to be controlled as a single group for use, not for wattage.

 

[Coppersmith]

AFAIK, you can go up to 100% of the dimmer rating. They do get warm at 100% but should be safe. Like Larry said, it's based on what you installed. I would caution the HO however.

 

[Strathead]

I'd say that, like most NEC rules, it's based on what is installed, not what could be installed.

To add, that is still a lot of lights to be controlled as a single group for use, not for wattage.

Not in this case. 220.14(D) Luminaires. An outlet supplying luminaire(s) shall e calculated based on the maximum volt-ampere rating of the equipment and lamps for which the luminaire is rated.

I am not going to take the time to try and propose a change to the NEC, I am far lazier than some of those here, however, this is definitely a code that should be changed. It should allow a fixture's maximum volt-amperage to be lowered by re identifying with a permanent marker. or other permanent means. (class II power supplies are a viable precedent).

 

[Frank DuVal]

maximum volt-ampere rating of the equipment and lamps for which the luminaire is rated.

I take that to mean the entire luminaire, which for recessed lights is the hidden part and the trim. Complete assembly. So, if you are supplying LED trims, you know your kVA needs. If you are not supplying trims, then ......:thumbsdown:

 

[Strathead]

I take that to mean the entire luminaire, which for recessed lights is the hidden part and the trim. Complete assembly. So, if you are supplying LED trims, you know your kVA needs. If you are not supplying trims, then ......:thumbsdown:

If the trims have an edison base and the can is stamped with a wattage then I believe you have to use that wattage. If you have to cut off the lampholder and install the trim then I could see some AHJ's looking the other way, but technically the listed wattage is still per 410. In my opinion. Hopefully others will chime in.

 

[growler]

some dimmers are 600 W incandescent or 150 W LED rated. In a new house, its hard to know when the new owner will request a dimmer in place of a switch. The LED light trim kits I use are 9 or 10 watts each. So I put 12 can lights on one dimmer, (80 % of 150 W) But before LEDs, we could only put 7 lights. Most customers use LED, but what if they used incandescent ? Is there a NEC rule here? Do I need to assume incandescent to play it safe and only put 7 ? Thank you.

They do make dimmers that are rated for more than 600 W. Just because they are listed as commercial dimmers doesn't mean they can't be used for residential.

For practical purposes I wouldn't put to many lights on one switch or dimmer. I charge for each switch or dimmer installed so it's to my benefit to install more and not less.

 

[GoldDigger]

AFAIK, you can go up to 100% of the dimmer rating. They do get warm at 100% but should be safe. Like Larry said, it's based on what you installed. I would caution the HO however.

But be aware of the mandatory derating of many dimmers if placed adjacent to another dimmer in a multi-gang box.