Over Current Relay

100SR Relay

100SR Self-powered Overcurrent Relay


  • The 100SR O/C Relay is a self-powered relay that does not require any auxiliary power or a battery to operate. This equipment receives power through the additionally installed CT for power, and uses it to perform protection operations.
  • The 100SR Relay is designed for fast-restart and a low power structure, and thus the Relay can perform protection operation at low currents.

Main Functions

  • Intuitive user interface and front panel
  • Phase and Ground Overcurrent Protection
  • Set all protection element parameters for phase and ground by using the Rotary switch on the front panel
    • The multiples for TCC Type (EI, VI, NI, and Definite Time), pickup level, and definite time, the multiples for time dial, and instantaneous O/C, and definite time

  • Indicate the phase information occurred faults recently through the latch relay and the capacitor
  • Run, fault pickup, and fault indicator
  • Test button for lamp test
  • Reset button for fault targets
  • Button to check a phase that occurred faults recently
  • Wake Up button to operate a device by connecting a separate DC auxiliary power.


  • Places where protection is required for distribution networks and load incoming lines
  • Places where connection with the automation system is not required
  • Places where protection is required for underground lines that have difficulty supplying auxiliary power


  • Since auxiliary power is not required, installation cost is reduced.

Related Products

  • Local control panel
  • Power devices and CT for power