New light fixture, old wiring

Old 04-18-03, 11:17 AM
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New light fixture, old wiring

My house was built in 1927, and I know the only electrical work done since 1985 was when I upgraded the service to 150 amps.

I want to install a new ceiling light fixture, but the instructions say that it should be used with wiring rated for 90 degrees C - as most wiring prior to 1985 is only rated to 60 degrees C. My question is this: Will I safely avoid a fire hazard if I only use low-wattage, high-efficiency bulbs, and not incandescent bulbs? The fixture currently in place is for a single, 100-watt bulb.

I'm in Wisconsin, US.

Thanks very much in advance!
Old 04-18-03, 11:21 AM
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Do have access above the fixture where a junction box could be placed and a new piece of cable ran to the fixture box?
Old 04-18-03, 12:34 PM
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Lowering the wattage of your bulbs would decrease the ambient temperature in your fixture box and would definitely be recommended if the wiring cannot be updated.

I think the 90 degree wiring label is more to protect the light fixture manufacturer than the home owner. The problem with older wiring is that the many years of service directly above light fixtures can deteriorate the insulation on the wires. This is especially true if a homeowner has been burning two 100 watt bulbs in a fixture designed for two 60 watt bulbs, which is very commonly done. I've pulled down many fixtures and had the insulation snap off the wires when I pulled them out of the box because they were so brittle. That said, if and when you pull the wiring out of the fixture box to replace your fixture, if the conductors are still flexible then I probably wouldn't worry about it. That would mean that the location has had well insulated fixtures that haven't been "over-wattaged". If you had crumbly brittle wire and replaced a fixture with a new one and your house burned down with the fire starting at the fixture, the manufacturer wouldn't have any liability because you didn't install the fixture on 90 degree wire.
Old 04-18-03, 08:02 PM
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Texsparky - The fixture is on my first floor; the only access would be to go up through the ceiling.

mcjunk - I'll check the condition of the wiring when I remove the old fixture. Based on your description, I'll deal with whatever I find.

Thanks very much to both of you...I really appreciate it!

- CG

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