The ampacity of types NM and NMC cable corresponds to what degree C conductors?

The correct understanding lies in the fact that the ampacity of types NM (Non-Metallic) and NMC (Non-Metallic sheathed cable) is determined based on specific temperature ratings of the conductors. For NM and NMC cables, the conductors are typically rated for a maximum temperature of 60 degrees Celsius.

This temperature rating is essential for ensuring safe electrical installations, as it directly impacts the current-carrying capacity of the conductors. If the conductors exceed their rated temperature, it can lead to overheating, insulation failure, and potential fire hazards.

In practical applications, electrical codes and standards, such as the National Electrical Code (NEC), specifically reference these temperature ratings to help electricians determine the proper ampacity for the installation based on ambient conditions, application, and installation method. This is why the ampacity of NM and NMC cables corresponds to 60 degrees Celsius conductors.