NM Cable Temperature limitations

[patron]

I have come across NEMA Bulletin No. 92 which states that when installing a recess light fixture with a required supply conductor insulation rating of 90 deg. in a house that is wired with type NM cable ( 60 deg.) you should install a junction box 18" away from the fixture and switch over to type NM-B cable ( 90 deg.) to run into the fixture. Is this a common practice? Does anyone really do this?

 

[nakulak]

does anyone use anything but nm-b anymore ?

 

[augie47]

Welcome to the Forum.
Seems a mute point to me as the only NM on the market for a number of years now has been NM-B.
If you happened to have a retrofit where some old (original) NM was is in use some transition would be necessary.

 

[patron]

I am talking about retrofit situations in houses built before 1984.

 

[infinity]

I am talking about retrofit situations in houses built before 1984.

That's the way we do it. This is also SOP for older homes with AC cable that contained rubber insulated conductors.

 

[augie47]

In this area, on retro-fit jobs whatever is installed must meet present Code, so some transition would be needed if the fixture called for 90? wiring.

 

[patron]

Thanks to all who replied. I know this is a no brain er, but in all the classes and training that I have had over 20 years nobody ever pointed this out. I should have, but I never realized that the old NM was only rated at 60 deg. You never stop learning.