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Cable Capacity Check

Compare design current and protective-device rating with a user-entered cable ampacity after a verified combined correction factor. No cable tables are included.

Inputs

Candidate cable inputs

Range: 0–100,000 A

Enter the design current Ib for the circuit after the applicable load assessment.

Range: 0.01–100,000 A

Enter the uncorrected or reference ampacity from a verified cable source. No AS/NZS 3008 table is included.

Range: 0.01–2

Enter the combined factor you have determined for the actual installation conditions. This tool does not calculate grouping, ambient, thermal or installation-method factors.

Range: 0.1–100,000 A

Enter the protective-device rated current In. This is compared with the corrected capacity; it is not a trip-curve or fault-interrupt rating.

Result

Capacity minus design current (A)
0.60
Adjusted capacity from entered inputs (A)
25.60
Capacity minus device rating (A)
0.60
Limiting capacity margin (A)
0.60
Cable capacity check
The adjusted cable capacity meets both entered comparators. Confirm voltage drop, fault withstand, terminations, device curves and applicable requirements separately.

Formula

Calculation logic

Formula definitions and substituted values.

Before relying on the result

  • Check a candidate cable using manufacturer ampacity data
  • See how a user-entered correction factor changes usable capacity
  • Use verified cable data and installation assumptions as inputs; this tool exposes the limiting arithmetic margin but does not select a cable or determine compliance.

Related calculators

Use verified cable data and installation assumptions as inputs; this tool exposes the limiting arithmetic margin but does not select a cable or determine compliance.