Products  /  Function  /  High Impedance Differential  /  1M124


  • Compact single tier BUS bar protection system „
  • Incorporates Reyrolle DAD-N numeric high impedance differential relay
  • Built in CT supervision „
  • Trip rated programmable output contacts „
  • Integrated supply supervision „
  • Integrated fault & disturbance waveform recording „
  • SCADA communications „
  • High speed operation „
  • Wide range of settings „
  • High stability „
  • Integrated 3 Phase Metrosils & stabilizing resistors „
  • Adjustable stabilizing resistors „
  • Integrated multi trip relay „
  • Optional trip supply supervision „
  • Pre assembled & wired in 4U high 19” sub rack „
  • Made in Australia

High impedance protection schemes are widely used for the protection of BUS bars, generators, motors & power transformers. BUS bar protection schemes utilizing electromechanical high impedance differential relays are often used due to their simplicity, reliability & comparatively low cost. Numeric high impedance differential relays are now available & offer advantages of event & fault disturbance records as well as integrated CT supervision. While the application of electro mechanical schemes is likely to continue at least in the role of the Y protection scheme where duplicate protection is employed, numeric protection schemes are becoming more popular. The 1M124 system is an integrated protection scheme which overcomes the issue of space constraints on the protection panel & the problem of where & how to mount the Metrosil & stabilizing resistor elements. All of these functions have been incorporated into a single tier, 4U high, 19 inch sub rack frame.