Electrical Cable Size Calculator
Estimate a PVC conductor size from load, cable route and voltage-drop budget.
Scope: PVC 70°C, 1.5–70 mm² copper or 2.5–70 mm² aluminium, B2 or C installations only. Three-loaded-conductor ratings are used for both supply types as a conservative screening basis. Temperature and bunched-circuit factors are applied. Three phase assumes balanced loading without significant neutral harmonics. Enter electrical input power, not motor shaft output.
Voltage drop uses R = 23.7/S (copper) or 37.6/S (aluminium) Ω/km and assumed X = 0.08 Ω/km, a conservative resistance approximation for this PVC screening tool. The entered drop budget applies only to this cable; account for upstream drop separately. No spare-load allowance is added.
Preliminary estimate, not installation approval. A qualified electrical professional must verify manufacturer ratings, local requirements, breaker coordination, short-circuit withstand, fault disconnection, neutral/earth sizing and motor starting. Buried cables, thermally insulated walls, XLPE, parallel runs and leading power factor are outside this tool’s scope.
Reference: Schneider Electric Electrical Installation Guide, cable sizing (G20, G12, G16) and steady-load voltage drop.
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Worked example
With the default 5 kW electrical input, 230 V single phase and 0.9 power factor, current is 24.15 A. For copper, B2 installation, 40°C, one circuit and a 30 m one-way route, the tool selects 6 mm² from its stated screening table: corrected capacity 29.58 A and estimated drop 5.20 V (2.26%), within the entered 3% cable-only budget. This is an arithmetic example under the listed assumptions; it does not complete protection, fault or installation verification.