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-   -   How many lights on one branch, how to determine? (http://www.diychatroom.com/f18/how-many-lights-one-branch-how-determine-37688/)

 harleysilo 02-05-2009 02:04 PM

How many lights on one branch, how to determine?

In my Kitchen I have several sources of light.

A single switched light over my kitchen table. A Single switched light over the sink. And a 3 way lighted hood over the island cooktop (this used to supply a center ceiling light). This is not enough light.

What I think needs to be done, is the 3 way source for the hood needs to be diverted to power can lights in the kitchen, and a new source pulled to power the hood so it's not on a light switch anymore. I am concerned with the number of cans that this source can safely provide power too.

What do I need to do to determine how many cans i can run? Can I use this same circuit for the hood as well.

I'm guessing I need to add up all the amps each bulb and/or the hood will pull, and make sure it's under the breaker number, but am not sure.

 Scuba_Dave 02-05-2009 02:28 PM

You can load a residential lighting circuit to the Max capacity of the fixtures. So if the fixtures are rated for 100w you can have 18 on a 15a 1800w circuit, 24 on a 2400w circuit

I pull much less then what my fixtures are rated for due to switching to CFL bulbs. But you must go by the fixture MAX rating

You need to verify what else is on the circuit you will use
Also note that dimmers are usually rated for less then the full capacity
So if you have dimmers rated for 600w you would need 3 dimmers to control 1800w of lights

 harleysilo 02-05-2009 02:41 PM

Quote:
 Originally Posted by Scuba_Dave (Post 225683) You can load a residential lighting circuit to the Max capacity of the fixtures. So if the fixtures are rated for 100w you can have 18 on a 15a 1800w circuit, 24 on a 2400w circuit I pull much less then what my fixtures are rated for due to switching to CFL bulbs. But you must go by the fixture MAX rating You need to verify what else is on the circuit you will use Also note that dimmers are usually rated for less then the full capacity So if you have dimmers rated for 600w you would need 3 dimmers to control 1800w of lights
I understand to look at the breaker to determine max amps. Where do I find 1800w for example or your 2400w example.

 Scuba_Dave 02-05-2009 03:00 PM

A 15a circuit is 1800 watts - 14g wire
A 20a circuit is 2400 watts - 12g wire

 harleysilo 02-05-2009 03:02 PM

Quote:
 Originally Posted by Scuba_Dave (Post 225694) A 15a circuit is 1800 watts - 14g wire A 20a circuit is 2400 watts - 12g wire
Okay so I should double check the gauge of the existing wire, make sure it's correct with respect to the current breaker, then I'll know what my capabilities are. Sounds like it will be plenty for the lights. I'll need to see what the hood draws as well.

Thanks for patiently explaining this.

 rustic 02-05-2009 03:06 PM

what i did in my kitchen is--

6 recessed cans rated for 50 watts each= 300 watts

2 island mini pendants rated for 60 watts each=120 watts

30 10 watt undercabinet lights=300 watts

also 2 outside door lights,60 watts each=120 watts

also planning on 2 flourescent carport lights, 100 watts max(guesstimate)

so that is 1040 watts on my 15 amp breaker

gonna have my hood on its own circuit

 Scuba_Dave 02-05-2009 03:11 PM

There is no 80% load limit on a residential lighting circuit

 rustic 02-05-2009 03:13 PM