Many motors, transformers and generators are fitted with positive temperature co-efficient thermistor temperature sensors. The addition of a thermistor trip relay will provide full protection against sustained overload, single phasing, locked rotor, blocked ventilation and high ambient temperature. Thermistor trip relays continuously monitor the working temperature inside electrical equipment. When the temperature exceeds a safe limit, the relay can be used to shut down equipment until it regains a safe operating temperature.
