VΔAvailable
Voltage Drop Calculator
CalculatorEstimate device voltage and cable loss for two-wire DC or single-phase AC circuits using copper size or manufacturer resistance.
Open calculatorEngineering tools
Motor Current & Current Sensor Range
Estimate running line current from shaft horsepower, efficiency, voltage, phase, and power factor; find a matching sensor range.
Quick start
Enter motor shaft horsepower, efficiency and power factor, then choose supply phase and voltage. Select Calculate to estimate running current and compare the five listed sensor ranges. Use line-to-line voltage for balanced three-phase supply.
Inputs
Result
Enable JavaScript to calculate.
Method & assumptions
1φ: I = HP × 745.699872 / (V × η × PF)
3φ: I = HP × 745.699872 / (√3 × VLL × η × PF)
Efficiency η is the entered percentage divided by 100. HP is mechanical shaft output at the evaluated load. A rated HP input estimates operation at rated shaft output, not actual part-load current. The sensor range is the smallest of 0–10, 0–20, 0–50, 0–100, or 0–150 A containing the unrounded result.
Reference: ABB / Baldor · Power factor and efficiency · Methods, conversion conventions, and source notes
Worked example
10 HP, 90% efficiency, three-phase, 460 V, and PF 0.85 gives approximately 12.234 A; the listed range is 0–20 A.
Frequently asked questions
Is this measured full-load current?
No. It is an estimate from supplied shaft power, efficiency, and power factor. Use nameplate or measured current where available.
Recommended parts
Product recommendations have not been added. Calculated values are not product endorsements.
About recommended parts