Service Duty

In this case, S1 shows that this is a continuous duty motor that works at a constant load for enough time to reach temperature equilibrium.

The parameter Duty/Time rating represents the period of time during which the motor can run at its nameplate rating/rated load safely and indicates whether the motor is rated for continuous duty.

This is shown as “CONT” for continuous duty 24/7 but they can also have a short-time rating from 5 to 60 minutes, most motors are rated for continuous duty.

The rating of the motor is the ambient temperature vs. the time it can operate at that temperature, the EIC break this down into ten ratings.