Motor starting current
Estimate motor current and explore a starting-current multiplier. Use nameplate and manufacturer data for the actual motor.
Enable JavaScript for live calculations. Read the method and default example below.
Method and assumptions
- Running current = shaft kW × 1000 / (supply factor × voltage × power factor × efficiency).
- Starting current = estimated running current × entered multiplier. The method selection does not silently change this assumption.
Before using the result
- This does not predict acceleration, torque, voltage dip or starter compatibility. Verify nameplate current, motor connection and protection coordination.
Worked example
Illustrative default inputs. Enter your project values above.
- Motor shaft power
- 55 kW
- Supply voltage
- 415 V
- Supply arrangement
- Three phase — balanced
- Starting method
- Direct on line
- Motor efficiency
- 92 %
- Running power factor
- 0.86
- Starting-current multiplier
- 6 × running current
Default results
- Estimated running current
- 96.7 A
- Starting-current scenario
- 580.3 A
- Entered multiplier
- 6 ×
Choose a reference or send your BOQ
Compare relevant product families, then confirm the exact rating, control supply and duty. Price and availability are confirmed with your enquiry.
Technical references
These references support planning. The exact model documentation and a project-specific engineering review govern the final specification.