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# wiring fixture with multiple lights

#1
03-06-04, 01:09 PM
scout3
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wiring fixture with multiple lights

I know how to build a basic light fixture with one bulb, but would like to know how exactly to wire a lightfixture with 2 or more bulbs (like a chandelier).
I think it is called a parallel curcuit (when one light bulb goes out the other light bulbs stay on) as opposed to a serial curcuit?

After looking in a physics book I am pretty sure how to do it, but would like to hear it from a real person.

Are there different safety concerns with a multiple light fixture plugged into one outlet with a lamp cord, than with a simple one-bulb light?

I have looked all over the internet and library, but haven't found anything. A diagram sure would help.

Claudia

#2
03-07-04, 10:32 AM
Member
Join Date: Jun 2003
Location: Anderson, IN
Posts: 386
The wiring is as you said, in parallel. all of the "hot wires" would be connected together, and all of the "neutral wires" would be connected together, and all of the ground wires would be connected together (if available). The major safety concern is that you do not exceed the capacity of the cord suppling your lamp. Each bulb you add, adds to the total number of amps required by your lamp. The cord suppling the lamp has a maximum current rating. The total ampacity of your lamp cannot exceed this value without a severe risk of fire.

Scott E.

#3
03-09-04, 07:11 AM
scout3
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Ok, I think I figured it out.

Watt = ampere x volts

Therefore 60 watt light bulb = ampere x 110V (or 120?)

-----> one 60W light bulb = 0.55 amps ---> You can approximately "plug in" 27 60W light bulbs into a lamp cord, because a lamp cord can usually take 15 amps (breaker switch)? Right?

I hope my housewife physics is understandable?

#4
03-09-04, 08:00 AM
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Join Date: Sep 2003
Location: Central New York State
Posts: 13,246
You are making an incorrect assumption.

The breaker may be 15 amps, or it may be 20 amps. For this discussion that is not important.

Most cord and plug connected lamps have 18 gauge two conductor wire, usually with a polarized plug. This 18 gauge wire is smaller and not as well insulated as the wire in your walls, which is typically 14 or 12 gauge, but certainly no smaller.

Now there is a difference. The wiring in your walls is in your walls, coexisting with other wires, insulation, wall board, lathe, or whatever. The wire from the plug to the lamp is out in the air, resting (by gravity) on the floor, the table, etc. because it is in air it stays cooler.

If you had a light ficture with 27 bulbs, you would need heavier wire than the typical 18 gauge wire used in most lamps.

Light fixtures that are hardwired to a ceiling box (or wall box, or whatever) are similar, and must have wire rated for the current the fixture is designed to draw.

#5
03-09-04, 12:52 PM
scout3
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27 bulbs

I see! .....but a lamp cord could handle 3-5 light bulbs, does it not? Maybe lower wattage than 60?

Or is that the reason that I have a problem to find a hanging lamp with several light bulbs that does not need to be hard wired?

#6
03-10-04, 07:17 PM
Member
Join Date: Jun 2003
Location: Anderson, IN
Posts: 386
I have seen hanging lamps like you describe. It may be that people do not like having the cords (and usually chains) drape down the walls.