IMD125 Insulation Monitoring Device

  • Insulation monitoring according to IEC 61557-8
  • Selectable charging modes – CCS or CHAdeMO
  • Compliant with UL 2231-1 and UL 2231-2
  • Suitable for network voltages up to 1250VDC
  • Maximum system leakage capacitance – 25µF
  • Adjustable insulation resistance thresholds – Fault 125kΩ, Warning 625kΩ
  • Isolated MODBUS RTU or Canbus connection options

The IMD125 is an advanced insulation monitoring device (IMD) designed to continuously monitor insulation resistance in unearthed (IT) electrical systems, with particular focus on high-voltage DC applications such as electric vehicle (EV) charging infrastructure. Supporting operating voltages up to 1250V DC, the IMD125 provides continuous supervision of system insulation, enabling early detection of insulation deterioration and earth faults before they develop into critical failures. Compliant with IEC 61557-8, the IMD125 helps improve system safety, maximise equipment availability, and reduce unplanned downtime, making it ideally suited to the next generation of DC fast chargers, including high-power and Megawatt Charging System (MCS) applications.

  • Monitoring function: Insulation resistance
  • Max. network voltage: 1250VDC
  • Max. system leakage capacitance: 25µF
  • Aux. supply voltage: 12 – 24VDC
  • Output: 2 x SPNO – 5A @250V (AC1)
  • Dimensions (mm): W:71.4 x H:90.2 x D:57.4
  • Product standards: IEC 61851-1/BS EN 61851-1, IEC 61557-8/BS EN 61557-8, IEC 61851-23, UL 2231-1, UL 2231-2, IEC 61326-2-4/BS EN 61326-2-4