Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I bought a light fixture that has a min 90°C warning. The wiring leading up to the fixture is NM (60°C wire). I was wondering if an easy workaround to this would be to install a newer, more energy efficient light bulb to keep the temperature of the wire down.

Is this a viable solution to this problem? The next option is to replace the last 2 feet of NM with wiring that is certified to 90°C.

share|improve this question
Are you sure you mean "minimum" 90C? – The Evil Greebo Oct 25 '12 at 14:06
Yes, its right on the box.. "MIN 90 C SUPPLY CONDUCTORS" – Styler Oct 25 '12 at 15:53
Are your sure you have 60°C wire? My admittedly outdated reference for Type NM cable under Construction Specifications, says essentially that conductors shall be rated 90°C but the allowed current shall be as for 60°C conductors. – bcworkz Oct 26 '12 at 3:33
I was under the impression that NM is 60°C and NM-B is 90°C – Styler Oct 26 '12 at 14:33

That's not a good workaround. Recessed Insulation Contact (IC) lighting fixtures have a target temperature of 90ºC in the junction box. Kinda crazy, but that's what it is. See NEMA Bulletin #92 (December 2005) which reads:

When the dwelling’s existing wiring is rated 60ºC, install a junction box approximately 18 inches away from the newly installed lighting fixture and then run Type NM-B from the junction box to the fixture.

Installing the energy efficient bulb will not meet code. You'll be fine. But how are you going to prevent the next owner from sticking a hefty bulb in there?

An alternative is to take that fixture back, find something with a GU-24 socket, and hope the vendor was smart enough to realize that GU-24 means lower heat.

share|improve this answer
My thoughts exactly wrt the next person.. – Styler Oct 28 '12 at 3:10

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.