Skip to content
Open calculators

Cable Short-Circuit Withstand Calculator

Calculate required conductor area and withstand current from fault current, clearing time and an entered k coefficient.

Inputs

Project inputs and assumptions

Range: 0–100,000,000 A

Enter the RMS fault-current basis for the conductor and fault duration. Confirm the fault type, source basis and whether the device clearing time is suitable for this adiabatic check.

Range: 0.0001–100,000 s

Enter the total protective-device clearing time in seconds, including the device operating time where applicable, not only relay pickup or detection time.

Range: 0.01–100,000 A√s/mm²

Enter the verified adiabatic k coefficient for the exact conductor material, insulation, initial temperature and final temperature basis. Do not substitute a generic value.

Range: 0.01–100,000 mm²

Enter the metallic conductor area being checked in mm². Confirm the conductor construction, joint/termination limits and installation basis separately.

Result

Conductor area margin (mm²)
-33.75
Withstand-current margin (A)
-12,272
Required conductor area (mm²)
68.75
Estimated withstand current (A)
12,728
Short-circuit withstand check
The selected conductor area is below the adiabatic area required by the entered fault current, clearing time and k coefficient. Review the conductor and protective-device data.

Formula

Calculation logic

Formula definitions and substituted values.

Before relying on the result

  • Check a selected cable against a short-circuit duty
  • Compare clearing time sensitivity for a fixed conductor area
  • Verify the selected k coefficient, conductor construction, fault type, peak duty, terminations and equipment withstand before final approval.

Related calculators

Verify the selected k coefficient, conductor construction, fault type, peak duty, terminations and equipment withstand before final approval.