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# Add lights to an existing circuit?

#1
05-15-05, 11:14 AM
tswitz
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Add lights to an existing circuit?

On one circuit, I already have 6 recessed halogen lights (line voltage GU-10 50 watt bulbs), and a celing fan/light combination (don't use the light, only the fan). I'd like to extend off of the ceiling fan an additional 7 of these fixtures. I can't find the amperage draw of these bulbs, and before I start cutting holes, would like to know if this will overload the circuit. It's standard 20 amp residential circuit, house was built in 1998.

Last edited by tswitz; 05-15-05 at 11:27 AM.
#2
05-15-05, 05:35 PM
Member
Join Date: Sep 2000
Location: United States
Posts: 18,497
Divide the wattage of the light bulb by 120 to get the amperage. So a 60-watt bulb draws one half amp.

So you currently have six 50-watt bulbs. That's 300 watts. You have a ceiling fan. That typically uses only 65 watts on high speed, plus whatever wattage bulbs you have in the light kit (but you say you don't use it). You want to add seven more 50-watt bulbs. That's another 350 watts. So you have in total 300+65+350, which is 715 watts. 715 watts divided by 120 is 6 amps. So even after adding the seven new lights, you'll only be using at most 6 of the 20 amps available.

This analysis depends on your assertion that the six 50-watt fixtures plus the fan are currently the only things on your 20-amp circuit. Double check all that information.

#3
05-16-05, 10:03 AM
tswitz
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Posts: n/a
OK, I went back and found all of the lights in the circuit:

I found an additional 300 watts (one lamp w. 2 40 watt bulbs, a chandelier with 4 x 25 W, and a half bath with 3 x 40 W), plus the stove (gas--only affects the pilot light/electric start and the clock).

Also, since this is US, the voltage is 110, correct?, so I'll have to change my math slightly. Total load = 1005 watts (plus the stove)/110 = 9.13 amp. I was told not to exceed 50% of the total amperage on the circuit, so I should be fine, correct? Also, would it make a difference if I used low-voltage instead of line voltage cans?

Thanks again.