ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

It is interesting that depeding on which document you look at for this device it might be restricted to NM-b only or any copper NM, it might be restricted to modular homes or in any dwelling. They seem to have had several changes of heart and still have documents around to allow the various uses.

A thought that popped into my head today: Wind the clock back to the late '70s doing maintenance/rehab type work.

easy job, replace hall light fixtures in 3 & 4 story multi-family bldgs. Old fixtures from the '50s; old tight spiral steel BX, pancake boxes with old gas nipples still there. Three wire (two circuits), two lamp surface mounted fixture, 100 watt bulbs.

Crumble disaster no matter how careful you were, down to the bare conductors. Boss says.."cut it back to good wire"!
Heck, it was luck IF there was any slack. A BX version of that TYCO gizmo would have saved countless hours.

Old, past sins committed ('buried boxes') are well past the statute of limitations.

Yup, only the installer and the fire department will ever know

How much 90 wire do you need before splicing on to 60 degree wire? This is not well defined and my answer is entirly inferred from other sources. Almost all product standards use 1.2 meters of wire as the default length to dissipate heat introduced at 1 end of the wire. Breaker tests use 4 feet. pot lights only use about 18 inches of 110 degree wire to get to the external JB where 90c wire is required.
When inspecting older homes I regualry reject new lights on old wiring. except for luminaires with a canopy and pendant most luminaires now have a 90c minimum temperature rating. so where new high temperature fixtures are installed on old 60c wiring it is pretty common to see no insulation on the wires if they are even touched. by splicing in 4 feet of wire between the old box and new luminaire we generally avoid this issue but the old JB is all to often in the exact location they want the new JB and light to be mounted. Not too hard if you can lift the box from the attic but the extension can be very hard to accomplish. It is usually best to find a luminaire that can be connected to 60c wire.

I have the same perspective also mikesh, with regard to older wiring and luminaire requirements,..there is always some way to get it done right or to the minimum requirements, it just takes a little more T&M.

How did this thread get this long without me?

90 degree? Heck, I frequently see a 105 degree requirement with the Ruud HID lights I use.

As I see it, the requirement ends as soon as you leave the enclosure. In practice, this means either a box on the opposite side of the wall, or a splice where the mounting meets the pole.

This has to be a requirement completely ignored by the trade, as the folks at Graybar have absolutely no idea what wire to supply. Inquiries typically get an answer involving a couple thousands feet of wire, with a price of $5/ft.

It seems that the electrical parts houses are completely ignorant of the high-temp appliance wire sold at the local hardware store or appliance repair shop. This is the stuff covered with woven fiberglass. 0.75/ft, cut to length, any color you want.

John..

MTW wire carries a 105ºC rating...

The last time i looked my THHN/THWN-2 also carried an MTW rating...

Look for this on #14 stranded tap wires.