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Electrical circuit worksheet

Carry a design current through copper V-75 cable sizing, voltage drop and protective-earth lookup. Keep the inputs and working in one printable record. No account needed.

Start with an assessed design current from maximum demand or your equipment data. This worksheet covers single-phase, above-ground multicore circuits without thermal insulation. Use the full cable calculator for other supported arrangements.

Supply and installation

The drop budget is for this run. Allow separately for upstream and downstream runs; 5% is not a fresh allowance for every segment. Protection selection and fault-loop checks remain separate.

Worked example

For 32 A over 30 m, single phase, PVC conduit in air at 40 °C, one circuit and a 5% budget: the existing screening model selects 6 mm², gives 3.14% voltage drop, and the copper earth lookup gives 2.5 mm². Change the conditions and review the new governing size.

Complete the remaining checks

Review the cable sizing method, then check fault-loop impedance and conduit fill. Use the inspection report builder to record observed findings and actual test results separately.

Print opens your browser's print dialog; choose Save as PDF where available. Drafts stay on this browser until removed. Avoid client details on shared devices.