Crompton PMM-T Thermistor Motor Protection Relay – PTC Input, Manual Reset

Description

Thermistor motor protection relay that monitors PTC (Positive Temperature Coefficient) thermistors embedded in motor windings. When the motor winding temperature exceeds the PTC trip threshold, the relay trips and disconnects the motor via its changeover contacts, preventing burnout from overheating. Manual reset ensures the operator must physically confirm the motor has cooled and investigate the cause before restarting. 2 changeover (CO) contacts rated 8A at 250VAC, with a wide 24–240VAC/DC supply range for universal installation.

Note: The motor must have PTC thermistors embedded in its windings (typically fitted at manufacture). Connect the PTC thermistor leads to the PMM-T input terminals, and wire the relay output contacts into the motor starter control circuit. Commonly used for pump motors, compressor motors, fan motors, and any application where winding temperature protection is critical.