\begin{tabular}{||c|p{5cm}|p{15cm}||} \hline\hline S1&Continuous duty&The motor works at a constant load for enough time to reach temperature equilibrium. \\ \hline S2&Short-time duty&The motor works at a constant load, but not long enough to reach temperature equilibrium. The rest periods are long enough for the motor to reach ambient temperature. \\ \hline S3&Intermittent periodic duty&Sequential, identical run and rest cycles with constant load. Temperature equilibrium is never reached. Starting current has little effect on temperature rise. \\ \hline S4&Intermittent periodic duty with starting&Sequential, identical start, run and rest cycles with constant load. Temperature equilibrium is not reached, but starting current affects temperature rise. \\ \hline S5&Intermittent periodic duty with electric braking&Sequential, identical cycles of starting, running at constant load and running with no load. No rest periods. \\ \hline S6&Continuous operation with intermittent load&Sequential, identical cycles of running with constant load and running with no load. No rest periods. \\ \hline S7&Continuous operation with electric braking&Sequential identical cycles of starting, running at constant load and electric braking. No rest periods. \\ \hline S8&Continuous operation with periodic changes in load and speed&Sequential, identical duty cycles run at constant load and given speed, then run at other constant loads and speeds. No rest periods. \\ \hline\hline