Cable Derating Factors Jun 2026

reduces this capacity based on the principle of heat dissipation. If a cable cannot dissipate heat effectively (due to surrounding insulation, high ambient temperature, or proximity to other cables), the current must be reduced to prevent the insulation from overheating and failing.

When current-carrying cables are placed close together, they mutually heat one another. The more cables in a group, the less heat dissipates, and the lower the allowable current per cable. cable derating factors