adding new light fixture to 30 amp circuit

Old 01-14-12, 12:07 PM
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adding new light fixture to 30 amp circuit

I want to add a pendant light over my dining table. I'll install a new box in the attic but the closest power is a box on a 30 amp circuit that powers the gas furnace. Is there any reason I shouldn't run off this circuit? The light fixture will never have more than a 100w bulb and will be controlled by a dimmer.

Also, if any of you generous neighbors could provide a diagram that goes power from box to fixture and from box to switch I'd be grateful just to double check my thinking. MANY thanks.
Old 01-14-12, 12:34 PM
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Is there any reason I shouldn't run off this circuit?
Yes. By code 120v lighting circuits are limited to 20 amps max. The fixtures and switches usually used are not rated for 30 amp. It is bad practice and usually a code violation to tap off a dedicated circuit such as your furnace circuit.

You need to find another source of power. A light fixture on a non-restricted circuit accessible from the attic that has power coming into it not the switch would be an example.


Last edited by ray2047; 01-15-12 at 05:33 PM.
Old 01-15-12, 03:44 PM
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You cannot tap the 30 amp circuit. It is prohibited as Ray has said.

Also there is a good chance the circuit is 240 and not 120 so you would not have a neutral.

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