• Insulation monitoring device for DC IT systems
  • Application control circuits
  • Two separately configurable response values
  • Multi-functional LC display
  • Passive measuring method without measuring voltage

The ISOMETER® monitors the asymmetrical insulation resistance of unearthed DC systems (IT systems) with nominal voltages of DC 12…120 V.

The maximum permissible system leakage capacitance Ce is 50 μF.

  • Features
  • Applications
  • Accessories
  • Ordering information
  • Downloads
  • Monitoring of asymmetrical insulation resistances for unearthed DC systems
  • Measurement of the system voltage (r.m.s. and DC) with undervoltage and overvoltage detection
  • Measurement of the system DC voltages to earth (L+/PE and L-/PE)
  • Configurable adaptation to the system leakage capacitance up to 5 μF
  • Selectable start-up delay, response delay and delay on release
  • Two separately adjustable response value ranges of 1…100 kΩ (Alarm 1, Alarm 2)
  • Alarm signalling via LEDs (AL1, AL2), a display and alarm relays (K1, K2)
  • N/C operation or N/O operation of the relays selectable
  • Measured value indication via multifunctional LCD
  • Fault memory can be activated
  • RS-485 (galvanically isolated) 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
  • Simple battery systems
  • Conveniently sized DC control voltage systems
  • DC lamp circuits


Mandatory accessories for ISOMETER® isoUG425

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

Variants of ISOMETER® isoUG425

TypeSupply voltage USNominal voltage UnSystem leakage
VersionArt. No.
isoUG425-D4-4AC 100…240 V, 47…63 Hz / DC 24…240 VDC 12…120 V≤ 50 μFpush-wire terminalB71036320

Downloads for ISOMETER® isoUG425



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