Overcurrent Relays

Overcurrent relay

Overcurrent thermal relays have been for a long time applied as the best protection of motors from current overloading. With the aid of an auxiliary contact they switch off the contactor and the motor itself. In this way they protect the motorĀ  against damage caused by overloading, rotor braking or phase failure, and assure reliable motor operation. There are four overload relay version available: TRB 14 for separate mounting with screws or quick mounting to the standard rail (35 mm) TRB14/KNL 16, TRB14/KNL 30 for direct mounting to KNL 22 and KNL 30 motor contactors, and TRB 14/KNL07 for direct mounting to contactors KNL 07. Minimal distance between overcurrent relays 15 mm.


  • Sensitivity to phase failure provided through differential breaking facility
  • Due to the built-in temperature compensation, no influence of ambient temperature oscilations on the release characteristic.
  • Simple mounting on contactor.
  • Break and make contacts galvanic separated.
  • Covered terminals – protection against touch according to VBG and VDE 0106, part 100.
  • Possibility of screwing down on flat basis.
  • Possibility of fixing to the rail (35 mm).
  • Accurately current setting.
  • Handle for simulation of bimetal relay operation. (Test)
  • Multi-function – off key (red), reset key (green)
  • Green reset key indicates at the same time the switch position.
  • Reset switching choose – automatic or manual.
  • Marking of connection terminals according to EN 50 005
  • Repeat terminal 95 – easier contactor mounting.