Every new light fixture you can buy today has a warning label which states “For supply connections, use wire rated for at least 90 degrees C.” I know these fixtures require NM B wire and that houses built before 1985 do not meet these requirements. I know that the insulation pre 1985 is subject to melting inside the junction box due to the heat generated by newer fixtures.
So what is the PRACTICAL solution for a home with older wiring and why is it that even a single 60 watt fixture built today generates more heat than one built prior to 1985?
Thanks.
JDMS
Replies
Concern over this is another reason, if this was the only issue I would probably not rewire, to consider rewiring. But if your wiring is old enough to make this a problem it is likely in need of other work and rewiring is the surest solution. At the same time receptacles, fixtures, circuits (A dedicated computer circuit is a good idea.) or panel could be added, updated, repaired or, at the very least, looked at.
OK. That said and out of the way I will assume that you don't want to rewire in the near term. How do you handle this? First get some modern wire. Eight inches of the same gauge as the circuit will do. Wire nut the 90 degree wire to the older 60 or 75 degree wire and connect the fixture wire to the new stuff. Tuck the old wire into the bottom of the box away from the fixture and allow the 8" piece to bridge the distance. The old wire should not contact or be any nearer to the fixture wire than necessary.
This is a relatively safe solution and I would expect no more problems with this fixture but take the extra trouble as a sign of further and more frequent electrical problems in the future. Unlike wines, and a few people, wiring does not get better with age.
Once you get done pour yourself a coffee and consider saving enough money to get the place rewired. Houses can limp along like this for years
Thank you for your advice. The addition of a short piece of 90 degree rated wire sounds like a reasonable solution.
What I really do not understand is there really something DIFFERENT about the way fixtures are made today that makes them incompatiable with pre 1985 wiring? Or was this a problem with older fixtures and wiring and this labeling is just a way to cover everyone's butt? I mean what could possibly be the difference between a simple 60 watt ceiling fixture made in 1984 and one made today?
I don't know, but some of the other fixtures also required higher temp wire.
I replaced some square recessed lights that where in basement. They had ceramic sockets with fiber (asbestos?) insulation.
I believe the label on them indicated that they needed to hook to 105 C rated wires. Of course like evereything else that was screwed up in this house that "suggestion" was ignored and they used 1950's romex STUCK (no clamp or bushing) in the box.