Replacing light fixtures and wire ratings


  #1  
Old 02-02-03, 08:19 PM
debp
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Question Replacing light fixtures and wire ratings

I recently bought an older home (built in the mid-50's). I'd like to replace some of the light fixtures, but the new light fixtures warn about fire hazards and wire ratings of houses built before 1986 (60deg vs 90deg). Can someone please explain this to me? Do I really need to hire an electrician or is this something I can do with a good step by step explaination? I'd like to save some money and do as much fixing up as I can. Thanks!
 
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Old 02-02-03, 08:32 PM
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I suspect the manufacturer of the light fixture is simply covering themselves from liability. The reason the light fixture manufacturer gave such a warning is because the insulation of the wires they use is rated at a higher temperature (90 deg C) than the wire's insulation that was used in older homes (60 deg. C). Therefore if the older wires are used in the same environment (i.e. junction box, fixture housing, etc.) as the new wires, the integrity of the wires will be reduced to the lesser temperature rating of the older wire's insulation.

Personally, I would not be concerned about this warning. You could splice a short peice of new wiring (with a higher temperature rating) to run into the junction box or fixture housing, etc., but I wouldn't bother doing that myself. Just make sure the insulation of your older wires is not brittle whereas a short could happen. And this suggestion doesn't have anything to do with the warning you're asking about. It's just a good habit to check older wiring...

Kooter
 
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Old 02-03-03, 04:49 AM
J
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You must not use those fixtures if the wiring is not the correct rating. The heat from the fixtures will cook the old wiring. To repair this old wiring you need to replace the wire coming into the junction box with new 90* wire.
You can do this by installing another junction box for the old wire and run a short piece of new wire to the fixture box.

The previous poster is WRONG. Do not ignore the warning.
 
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Old 02-03-03, 07:26 AM
J
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Most, but not all fixtures, have a requirement for 90-degree wiring. Look for fixtures that hold the bulb some distance away from the junction box. These are much less likely to carry the warning, and thus can be installed on 60-degree wire.

I agree with the advice to not ignore the warning. Either buy fixtures that don't have it, or replace the last foot or two of wire using the technique Joe gave, with an extra permanently accessible junction box. If practical, it would be even better to replace all the wiring back to the prior junction box.

Make sure you strictly follow the manufacturer's instructions about maximum bulb wattage.
 
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Old 02-03-03, 10:47 AM
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What type of fixture are we talking about here? Recessed can-lights will have a temperature sensor to cut off the voltage if the heat rises too much. Most fixtures using halogen lamps are designed to have the junction box away from the heat generated from the lamp source. Incandescent fixtures such as chandeliers have the lamps far away from the house wiring.

I'm not suggesting this person's fixture isn't something unusual that truly requires 90 deg. C (194 deg. F) wire insulation but I really rather doubt it.

Kooter

PS - If you use any electrical tape on that wire be sure to use something like 3M's 33+ instead of an economical electrical tape [like most electricians use] such as 3M's Temflex electrical tape because it is only rated at 80 deg. C (176 deg. F)!
 
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Old 02-04-03, 10:18 PM
debp
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Thank you!

Thank you for everyone's replies. I appreciate your help with this. I am trying to replace a hall light (it now hangs down from the ceiling like a chandelier) with a simple mushroom light. All of the lights I saw at the hardware store warn of the wire rating issue. Thanks again for your responses. I'll let you know how is goes.
 
 

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