Charging of Electric Motors

In electric motors, it is important to limit the increase in losses by performing adequate maintenance of the machines and mechanical drive components, such as adjusting the clearances, proper lubrication, checking the alignments. We should note that individual motors are generally more energy-efficient than multiple transmissions. For information, we can see below the decrease in the efficiency of a three-phase asynchronous motor of 75 hp, four poles, depending on the load presented in normal operating conditions.

An electric motor enerpac pem-1401b is sized to provide a nominal torque Cn, at a nominal speed Nn. That is, for a nominal power Pn, we have: Pn = Cn x Nn The electrical losses (or thermal losses) vary with the square of the resistant (load) conjugate. In a well sized motor, the strength of the torque must be less than the rated torque, but if it is equal to or slightly higher, the resulting heating will be considerable. On the other hand, an “underloaded” motor has a noticeable reduction in efficiency. The ideal load should match the workload to be done, which is not always easy to achieve. If the work required of the driven machine has temporary overloads, the motor power should be slightly higher than the required power.