Insulation Monitoring Devices (IMD)

The insulation resistance of unearthed (ungrounded) networks (aka IT systems) has to be permanently monitored by insulation monitoring devices (IMD). An insulation monitor triggers an alarm if the value falls below the response value.

The IMD is connected between the active wires of the IT system and the protective conductor (PE). A measuring current is superimposed on the network and then recorded and evaluated by a measuring circuit. In this way, the monitoring device detects deterioration in the insulation level reliably at an early stage.

Basically, an IMD is selected by:

  • area of ​​application,
  • the voltage level of the monitored network,
  • the type of voltage (AC, DC, or AC/DC as it occurs in inverter systems),
  • and the maximum permissible leakage capacity that has to be taken into account.

To provide you always with the latest information, we refer you here directly to the manufacturer's website.

For technical questions or offers, please contact the Bender distributor in your country directly. We would be happy to put you in touch - please contact us.