derating dimmers

[chrisdias]

2 quick questions so i don't burn the house down...

- when a switch is rated at 800w (Centralite Jetstream to be specific), that means it will handle up to 8 100w loads, correct? Or some combination of loads that add up to 800w. Is it up to me to determine how to achieve 800w? for example, could I have 10 lights with 80w bulbs, or 20 lights at 40w, or 8 lights at 100w, etc.?

- when the instructions say to "de-rate" when putting switches in multi-gang boxes (for example jetstream has to be de-rated from 800w to 600w) that just means i cannot load each switch with more than 600w on, correct? So again, if i had 12 lights across 2 switches (6 on each) each light could have 100w bulbs max.

Thanks,
Chris

 

[ano]

2 quick questions so i don't burn the house down...

- when a switch is rated at 800w (Centralite Jetstream to be specific), that means it will handle up to 8 100w loads, correct? Or some combination of loads that add up to 800w. Is it up to me to determine how to achieve 800w? for example, could I have 10 lights with 80w bulbs, or 20 lights at 40w, or 8 lights at 100w, etc.?

- when the instructions say to "de-rate" when putting switches in multi-gang boxes (for example jetstream has to be de-rated from 800w to 600w) that just means i cannot load each switch with more than 600w on, correct? So again, if i had 12 lights across 2 switches (6 on each) each light could have 100w bulbs max.

Thanks,
Chris

First, make sure the rating is for the type of light you are using, eg. incandescent. Second, while your technically correct that a 800W rated switch can control lights at the total wattage or less, it safer to make sure your switch can handle the FULL wattage listed for each light on the fixture.

For example, lets say you have an 800 watt switch, and your planning to control 16 50w bulbs. Seems O.K. but lets say the fixture is marked that it supports 75W bulbs? You move out, some other guy moves in and wants bigger bulbs so he installs 75w bulbs. Get the idea?

And you are correct, you must de-rate when you have dimmers next to each other.

 

[opie]

Ano is completely correct. Furthermore, if you don't adhere to the fixture ratings and there is some sort of problem, your insurance company might use that against you.

 

[chrisdias]

Ano is completely correct. Furthermore, if you don't adhere to the fixture ratings and there is some sort of problem, your insurance company might use that against you.

thanks guys - this is what i thought. just wanted to triple check before doing something stupid

 

[Steve]

Don't worry, you can quadruple check something and STILL do something stupid, I know I do