Work system can be divided into continuous, short, periodic or aperiodic types.

  Periodic working system includes one or more specified constant duration of load, and the load during the running of the motor does not reach the thermal stability; non periodic work of load and speed usually changes in operating within the range.

Working code usually indicated by S1~S10, the following are briefly introduced, we compare the common duty type.

  1 S1 operating system: continuous working system; keep in constant load operation to thermal steady state.

  2 S2 operating system: the short-time work system; according to the given time operation at constant load, the motor is not sufficient to achieve the thermal stability in the period of time, then stop and broken, the time is enough to make the motor cooling again. S2 should be marked with the duration of work, priority should be given to the 10, 30, 60 or 90 minutes.

  3 S3 operating system: the duty cycle; in a series of working cycle of the same operation, each cycle consisting of a constant load operation time and a down and off time, and the load during the running of the motor does not reach the thermal stability.