Introduction to Electrical Power and Power Electronics

156 Introduction to Electrical Power and Power Electronics

cable ampacity is limited by the continuous operating temperature limit, which, in

turn, is limited by the insulation type. The cable surface temperature is typically

limited to 60°C to 75°C for safety that depends on the application. The ampacity

depends also on the ambient air temperature, which can vary from 40°C to 65°C

depending on the cable routing (e.g., indoor, outdoor, in sun, in boiler room, etc.)

and on grouping in the raceway because of the mutual heating of the neighboring

conductors. A cable with three or four conductors in one jacket can carry less current

than a single ...