ECM Earth Continuity Relay

The ECM relay is designed to monitor the pilot earth continuity of trailing and reeling cables on earth fault-limited systems.
The ECM relay can be used in the following:

  • Open cut metalliferous mining
  • Underground mining


  • Electronic design
  • DIN rail or foot mount
  • Selectable trip level
  • LED indication to aid fault finding
  • AC or DC supply

The relay is available in two versions; ECM (with adjustable trip resistance values) and the ECM-R (with a fixed trip resistance and added remote start feature).

Both the ECM and ECM-R relays perform the following functions:

  • Ensures there is an earth return path from the machine back to the substation and/or distribution box
  • Provides an interlock circuit to ensure that if the pilot-earth continuity circuit is broken or short-circuited then the machine is isolated or cannot be energised
  • Ensures that by the time the pilot pin makes contact, when a plug is inserted into a receptacle, the phase pins are adequately engaged.