does this mean we cant replace newer fixtures onto old nmd cable that isnt rated for 90degrees... we have to sleave with 90 degree heat shrink before replacing a light fixture with a newer one.
I wonder if home depot salesperson tells the diyer about this
30-408 Wiring of ceiling outlet boxes
(1) Branch circuit conductors having insulation suitable for 90 °C shall be used for wiring of ceiling outlet boxes on which a luminaire is mounted, except for boxes in wet locations where Type NMW or NMWU cables are used.
(2) For purposes of compliance with this Rule, the ampacity of 90 °C wire shall be limited to the ampacity of 60 °C wire.
The conductors in ceiling outlet boxes are subjected to an increased operating temperature due to the additional heat from the luminaire mounted on the box. This can cause the conductor's insulation to deteriorate. Rule 30-408 requires that all branch circuit conductors installed in a ceiling outlet box on which a luminaire is, or might be, installed have insulation rated for at least 90 °C. An exception to the 90 °C insulation rating is allowed when the conductors are installed in a box in a wet location and the cables used are types NMW or NMWU.
Subrule (2) requires that the maximum ampacity of these conductors not exceed what is allowed for 60 °C insulated conductors. The purpose of this requirement is to reduce the heat from insulated conductors carrying the higher currents allowed for at the higher insulation temperature ratings