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ISOMETER® IRDH275BM-7 with AGH675S-7…

  • Insulation monitoring device for AC and DC IT systems
  • Application for drives including medium voltage converters up to 15.5 kV
  • In combination with AGH675S-7 and AGH675S- MV15
  • History memory with real-time clock for storing alarm messages with date and time
  • Galvanically isolated RS-485 interface for data exchange

The device combination ISOMETER® IRDH275BM-7 and the coupling device AGH675S-7 or the coupling devices AGH675S-7MV15 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 measurement method 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 optimise the measuring time.


  • Insulation monitoring for drives including medium voltage converters up to 15.5 kV
  • Two separately adjustable response values 100 kΩ…10 MΩ
  • AMPPlus measurement method (European patent: EP 0 654 673 B1)
  • Automatic adaptation to the system leakage capacitance
  • Info button 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 communication with other Bender devices (RS-485 electrically isolated)
  • Current output 0(4)…20mA (electrically isolated) analogously to the measured insulation value
  • Self monitoring with automatic alarm
  • Automatic self test, selectable
  • Connection for external kΩ indication
  • Test and reset button
  • Connection external test and reset button
  • Two separate alarm relays with two potential-free changeover contacts
  • N/O or N/C operation, selectable
  • Backlit two-line plain text display
  • Remote setting of specific parameters via Internet (option; COM465IP with at least Option C required)


  • 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

ISOMETER® IRDH275BM-7 with AGH675S-7… Variant(s)

TypeNominal voltage UnSupply voltage USCable lengthArt. No.
IRDH275BM-7--AC 19.2…55 V / DC 19.2…72 V--B91065120
AGH675S-7-2000AC/DC 0…7.2 kV, 0…460 Hz--2000 mmB913061
AGH675S-7-500AC/DC 0…7.2 kV, 0…460 Hz--500 mmB913060
AGH675S-7MV15-500AC/DC 0…15.5 kV, 0…460 Hz--500 mmB913058

Optional Accessories for ISOMETER® IRDH275BM-7 with AGH675S-7…

External kΩ measuring instruments (20 mA)

TypeSKMP *2Art. No.
9620-17212,8 MΩB986849

Downloads for ISOMETER® IRDH275BM-7 with AGH675S-7…

CE Declarations of conformity AGH 145.4 KB 2022/08/12 06:17:2512.08.2022 06:17:25
CE Declarations of conformity IRDH275 - 375 - 575 95.8 KB 2022/08/12 06:17:2512.08.2022 06:17:25
Manuals IRDH275BM-7 2.9 MB DE2020/09/11 10:13:5611.09.2020 10:13:56D00123
Manuals IRDH275BM-7 2.9 MB EN2020/09/11 10:14:1511.09.2020 10:14:15D00123
Datasheets IRDH275BM-7 mit AGH675S-7... 409.6 KB DE2019/09/10 10:36:4810.09.2019 10:36:48D00123
Datasheets IRDH275BM-7 with AGH675S-7... 363.1 KB EN2019/10/01 12:54:5201.10.2019 12:54:52D00123
Datasheets IRDH275BM-7 con AGH675S-7... 361.7 KB ES2019/09/10 10:37:0010.09.2019 10:37:00D00123
Datasheets IRDH275BM-7 514.8 KB ZH2019/05/13 10:31:3313.05.2019 10:31:33D00123
Quickstarts IRDH275BM-7 889.3 KB DE2021/03/02 10:13:2102.03.2021 10:13:21D00123
Quickstarts IRDH275BM-7 889.3 KB EN2021/03/02 10:13:2102.03.2021 10:13:21D00123