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Mixed-Cable Conduit Fill Calculator

Calculate circular area fill and minimum conduit diameter for two cable sizes with an entered fill limit.

Inputs

Project inputs and assumptions

Range: 0–10,000

Enter the number of cables with diameter A. Leave this group at zero only when the other cable group represents the route.

Range: 0.01–10,000 mm

Use the manufacturer outside diameter.

Range: 0–10,000

Enter the number of cables with diameter B. Leave this group at zero only when the other cable group represents the route.

Range: 0.01–10,000 mm

Use the manufacturer outside diameter.

Range: 0.01–10,000 mm

Use the actual internal diameter, not nominal trade size.

Range: 0.01–100 %

Enter the project fill assumption for this geometric comparison. The calculator does not select an Australian fill rule.

Result

Total cable area (mm²)
603.19
Fill margin (%)
-35.00
Calculated fill (%)
75.00
Minimum circular internal diameter (mm)
43.8
Result
The mixed cable area exceeds the entered geometric fill limit. Review the conduit size, cable arrangement and installation basis.

Formula

Calculation logic

Formula definitions and substituted values.

Before relying on the result

  • Check a conduit containing power and control cables of different diameters
  • Compare a selected conduit with the minimum implied by cable area
  • Use actual cable outside diameters and the applicable fill, segregation, heat and installation requirements; equal-cable assumptions are not used here.

Related calculators

Use actual cable outside diameters and the applicable fill, segregation, heat and installation requirements; equal-cable assumptions are not used here.