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Motor starting

Assess starting current, acceleration time and supply voltage dip.

IEC 60034 · NEC Article 430

1 · Motor nameplate Rating, supply connection and frequency

kW
Power unit
V
Phases

2 · Operating point Full-load efficiency, power factor and speed

p.u.
cos φ
rpm
rpm

Must be below synchronous speed (positive slip).

3 · Starting method Starter and locked-rotor data

× FLC
× rated

Optional. A blank KLR uses the IEC design code or NEC code letter, otherwise a flagged 6.5 × FLC screening default; a blank torque ratio assumes 1.5 (Design N).

4 · Mechanical load Inertia and load torque at the motor shaft

kg·m²
kg·m²
N·m

5 · Supply Point of common coupling and screening limit

MVA
V
%

Screening limit at the PCC; confirm against the supply authority's limit.

Jurisdiction
Results update as you change the motor, starter, load or supply.View results

Results

Review the voltage dip screen, starting performance and its limits.

solved
Detailed analysis Calculation, protection, checks, method comparison and audit

Document

Keep project details and calculation notes together.

Audit-ready sheet

Notes

  1. Motor performance per IEC 60034-1:2022.
  2. Locked-rotor current and torque per IEC 60034-12:2016 / NEC Table 430.7(B).
  3. Voltage dip is a simplified PCC screening — confirm against utility limits and cable-impedance study.
  4. Acceleration time uses the average-torque method; verify against the manufacturer torque-speed curve and locked-rotor withstand t_E.

References

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