Electrical question - recessed ceiling lights

ejb · Nov 21, 2005

Hi guys....

Quick electrical question: I need to install at least 4, and maybe 8 recessed ceiling "cans" in my family room to bring in some much needed light...its in the cieling of the 1 story section of my house, which is of course insulated with fiberglass...so I was looking at units at HD that are rated for use in direct contact with insulation, at picked out the right sized bulbs so as not to overheat...but then a tiny little mention in the install directions said I should make sure the supply line (wire) was rated for at least 90 degrees celcius...I couldn't find anything on my regular 14/2 or 12/2 roll of wires that indicated what temp it was rated for??? What kind of wire do I need to ensure that it will withstand 90 degress celcius?

beenthere · Nov 21, 2005

Good question, as I am diving into some old ceiling lights that have been 'buried' in the ceiling or 37 years. They show some signs of 'heating' the insulation around the wires.

Here is a site I found wire cable , that has the information you need, I think.

ericbx1500 · Nov 21, 2005

Not sure about 14/2 and 12/2 but THHN is rated for 90c.

mark1 · Nov 21, 2005

Maybe this will help

Look for the letters NMB on the jacket of the wire. The NM means nonmetallic sheath cable (Romex) and the B suffix means that the cable's conductors are rated for a maximum operating temperature of 90°C 194°F. We can assume that wiring made prior to 1984, without the B suffix, is rated at 60°C 140°F. This is the type of wiring found in most older homes that were built before 1982.