ISOMETER® isoHV425 with AGH422

ISOMETER® isoHV425 with AGH422

  • Continuous insulation monitoring at a nominal system voltage of AC/DC 0 V … 1000 V
  • Galvanically separated interface allows predictive maintenance of the system being monitored
  • Measurement of nominal system voltages and partial voltages to earth
  • Automatic adjustment to the system leakage capacitance up to 150 µF
  • Indication of the insulation value distribution (conductors L1/+ and L2/-) in DC systems

The ISOMETER® monitors the insulation resistance of unearthed AC, AC/DC and DC systems (IT systems) with nominal system voltages of 3(N)AC, AC/DC 0 … 1000 V or DC 0 …1000 V. The maximum permissible system leakage capacitance Ce is 150 μF. DC components existing in AC systems do not influence the operating characteristics, when a minimum load current of DC 100 mA flows. A separate supply voltage allows de-energised systems to be monitored too.

In order to meet the requirements of applicable standards, customised parameter settings must be made on the equipment in order to adapt it to local equipment and operating conditions. Please heed the limits of the area of application indicated in the technical specifications. Any use other than that described in this manual is regarded as improper.

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  • Monitoring the insulation resistance for unearthed AC/DC systems
  • Measurement of the mains voltage (true r.m.s.) with undervoltage and overvoltage detection
  • Measurement of DC system voltages to earth (L1+/PE and L2-/PE)
  • Automatic adaptation to the system leakage capacitance up to 150 μF
  • Selectable start-up delay, response delay and delay on release
  • Two separately adjustable response value ranges of 10...500 kΩ (Alarm 1, Alarm 2)
  • Alarm signalling via LEDs (AL1, AL2), a display and alarm relays (K1, K2)
  • Automatic device self test with connection monitoring
  • Selectable N/C or N/O relay operation
  • Measured value indication via a multifunctional LC display
  • Fault memory can be activated
  • RS-485 (galvanically separated) including the following protocols:
    –BMS interface (Bender measuring device interface) for data exchange with other Bender components
    – Modbus RTU
    – IsoData (for continuous data output)
  • Password protection to prevent unauthorised parameter changes
  • AC main circuits up to 1000 V
  • DC main circuits up to 1000 V
  • Systems including switched-mode power supplies


Mandatory accessories for ISOMETER® isoHV425 with AGH422

TypeArt. No.
Mounting clip for screw mounting (1 piece per device)B98060008

Variants of ISOMETER® isoHV425 with AGH422

TypeSupply voltage USNominal voltage UnVersionArt.-Nr.
isoHV425-D4-4 with AGH422AC 100…240 V, 47…63 Hz/DC 24…240 VAC-, 3(N)AC 0…1000 VPush-wire terminalB71036501
isoHV425W-D4-4 with AGH422WAC 100…240 V, 47…63 Hz/DC 24…240 VAC-, 3(N)AC 0…1000 VPush-wire terminalB71036501W

Downloads for ISOMETER® isoHV425 with AGH422



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