Work out duty cycle of motor instantly with clear inputs, formula shown and shareable results.
Duty cycle is run time divided by total cycle time, expressed as a percentage — the S3 intermittent duty class in IEC 60034. The cycle duration matters as much as the percentage: a 40% duty over ten minutes and over two hours produce very different peak winding temperatures.
Intermittent duty
duty % = run time / (run + rest); rated as S3 40% with a stated cycle duration
Thermal time constants. Short cycles average out, but long ones let the winding reach a much higher peak temperature even at the same duty percentage.
S1 continuous, S2 short-time, S3 intermittent periodic, S4 intermittent with starting, and so on up to S9. Each has a defined test cycle.