nm является маркой кабеля по системе NEC / UL (USA): NM = Non-metallic sheathed cable; -B = Conductors rated 90 C; NM-B = Non-metallic sheathed cable, type B (90 C conductors), for dry indoor wiring. 600 V, 90 C conductors (ampacity at the 60 C column). UL 719; NEC Article 334.
Non-metallic sheathed cable, type B (90 C conductors), for dry indoor wiring. 600 V, 90 C conductors (ampacity at the 60 C column). UL 719; NEC Article 334