The device combination A-ISOMETER® IRDH275BM-7 and the coupling device AGH675S-7 is designed to monitor the insulation resistance of unearthed medium voltage systems (IT systems). It is suitable for universal use in 3AC, combined AC / DC and DC systems. AC systems may include extensive DC-supplied loads. The AMPPlus measuring principle meets the particular requirements of modern power supplies which often include rectifiers, converters, thyristor-controlled DC drives and directly connected DC components. Taking the system leakage capacitances into account, the IRDH275BM-7 automatically adapts itself to the existing system conditions in order to optimize the measuring time.

• Insulation monitoring for drives including medium voltage converters up to 7.2 kV
• Two separately adjustable response values 100 kΩ…10 MΩ
• AMPPlus measuring principle (European Patent: EP 0 654 673 B1)
• Automatic adaptation to the system leakage capacitance
• Info key to display device settings and the system leakage capacitance
• History memory with real-time clock to store alarm messages with date and time stamp.
• BMS interface (BENDER Measuring Device Interface) for data exchange with other BENDER devices (RS-485 electrically isolated)
• Current output 0(4)…20mA (electrically isolated) analogously to the measured insulation value.

• AC, DC or AC / DC medium voltage systems
• AC / DC medium voltage systems with directly connected DC components, such as rectifiers, converters, and thyristor-controlled DC drives