How to Select the Power Cable Cross-Section?

How to Select the Power Cable Cross-Section?

The selection of a power cable's cross-section should be based on the following key principles:

  1. Rated Voltage: The cable's rated voltage must be greater than or equal to the rated voltage of the power supply system at the installation point.

  2. Current-Carrying Capacity: The cable's continuous allowable current must be equal to or greater than the maximum continuous current of the powered load.

  3. Short-Circuit Stability: The conductor cross-sectional area must be sufficient to withstand the thermal and dynamic stresses of a short-circuit fault in the power system, ensuring stability.

  4. Voltage Drop: The voltage drop along the cable length must be calculated and verified to meet the required standards for the proper operation of the end equipment.

  5. Protection Coordination: The short-circuit current at the end of the line must be sufficient to reliably activate the protective devices (e.g., fuses, circuit breakers) within the required time.