TeSys LT3

Relays processing PTC probe outputs, to protect motors from overheating.

Part of TeSys

TeSys LT3 thermistor protection relays are designed for use with PTC thermistor probes. The solution provides continuous temperature monitoring to protect machines (motors, generators, etc.) from damaging heat.

  • Presentations
  • Documents


TeSys LT3 thermistor protection relays monitor the temperature of machines via PTC thermistor probes to prevent over-heating.

  • LT3-SE: with automatic reset.

  • LT3-SA: with automatic reset; voltage fault indicator light incorporated.

  • LT3-SM: with manual reset; voltage fault indicator light, device “test" and "reset" button incorporated.


TeSys LT3 is a slim relay with built-in machine temperature control function, quick and simple selection.

  • Provide additional motor protections compared to standard overload relay.

  • Multiple control voltages available.

  • Wide band version from 24 to 230 V for LT3SA and LT3SM versions.


Suitable for a variety of applications in industry, infrastructure and building, including:

  • General protection and protection of motors with PTC probes.

  • Protection of resistors, bearings, capacitors.

  • Motors with frequent starts or operating in severe environments.