OPERATIONS

DUTY CYCLES :

Definitions ( IEC 34 - 1 )

1. Continuous Duty - Type S1 :

Operation at constant load for a sufficient amount of time for thermal equilibrium to be reached.

2. Short-time Duty - Type S2 :

Operation at constant load for a fixed amount of time, less than that required for thermal equilibrium to be reached, followed by a rest and de-energized period long enough to equalize the temperatures of the machine and the coolant to within 2 K.  

3.Intermittent periodic Duty - Type S3 :

A succession of identical duty cycle, each containing a period of operation at constant load and a rest and de-energized period. Here, the cycle is such that the starting current does not significantly affect the temperature rise.

4. Intermittent periodic Duty with starting - Type S4 :  

A succession of identical duty cycles consisting of an appreciable starting period, a period of operation at constant load and a rest and de-energized period.

5. Intermittent periodic Duty with electrical braking  - Type S5 :

A succession of periodic duty cycles, each containing a starting period, a period of operation at constant load, a period of rapid electrical braking and a rest and de-energized period.