Earth Leakage Detector



The interlocking circuits in railway signalling are often supplied from a battery in which neither of the poles are connected to earth. In the event of a single fault there is no danger, however, two or more faults occurring at the same time could create a dangerous situation. Therefore it is vitally important to supervise the battery supply continuously to prevent this from happening.

Cables which run in parallel with AC electrified railways are subjected to induced voltages. If an earth leakage occurs in the cable, these voltages can disturb devices which are connected to both cables. When earth faults occur in both supply and return wires yet another hazardous condition is created.

These faults are detected reliably with MRD’s Earth Leakage Detector.

  • Monitors AC and DC busbars
  • Auto detects busbar voltage
  • Fail-safe or non-fail-safe contact operation
  • Operation and alarm LEDs
  • Manual test and reset buttons
  • Adjustable sensitivity and delay
  • Displays fault level in KΩ
  • Displays fault time
  • DIN rail or panel mounting
  • RS-485 communications