The PROSTAR Motor Protection relay provides the most advanced capability available in the industry for the protection of induction motors.
This microprocessor-based system employs unique thermal models of the rotor and stator that take into account all important heating conditions affecting motor temperature. For the first time in the industry voltage and current are used to determine the speed-dependent heating in the rotor, allowing complete rotor protection. even high-inertia motors where the allowable locked rotor times is less than the normal starting time can be protected by the device without resorting to external devices such as speed switches.