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RN 5897/321

Insulation monitor

RN 5897/321


Auxiliary voltage

Alarm value

Prewarning value

Approvals and Markings


  • 0069399
  • RN5897.12/321/61 AC/DC24-60V
The insulation monitor RN 5897/321 of the VARIMETER IMD family is a solution for optimal... more

Product description

The insulation monitor RN 5897/321 of the VARIMETER IMD family is a solution for optimal insulation monitoring of modern IT systems. The device can be used in the most flexible way for AC, DC and AC/DC systems. Mains areas of applications are non-earthed DC charging stations for electric vehicles with mains voltages up to DC 1000 V, that need an extended temperature range. The setting of the parameters and the switching values is done via Modbus. All measured values, device statuses and parameters can also be read out via Modbus. All functions of the device can also be operated via Modbus. The operating status is indicated user friendly via a multicolour LED. With a sealable transparent cover the device is protectet against manipulation.

Technical specifications

Width: 52,5 mm
Classification: For DC charging stations
Response value: 1 - 500 kΩ
IMD type: AC, DC, AC/DC
Nominal voltage IT system: AC 0 - 230, AC 0 - 690 (Coupling device), DC 0 - 230, DC 0 - 1000 (Coupling device) V
Auxiliary voltage: AC/DC
Earth fault indicator: Yes
Approvals: UL
Response value type: Adjustable
Bus interface: Modbus RTU
Enclosure design: Distribution board
Type: RN 5897/321


  • Suitable for DC charging stations for electric vehicles acc. to IEC/EN 61851-23:2014/AC:2016-06
  • Insulation monitoring according to IEC/EN 61557-8
  • Universal application in non-earthed AC-, DC-, AC/DC networks up to AC max. 250 V resp. DC max. 300 V
  • Connection of an external coupling device RL 5898 for voltages up to AC 400 V / DC 500 V or RP 5898 for voltages up to AC 690 V / DC 1000 V possible
  • Extended operating temperature range of - 40 ... + 70 °C
  • Very fast reaction time ≤ 1 s
  • Optimised insulation resistance monitoring also during mains voltage variation
  • Self-test every full operating hours
  • Preventive fire and system protection
  • Detection of symmetric and asymmetric insulation faults
  • Easy adjustment of response values and setting parameter via Modbus
  • Suitable for large leakage capacitances up to 5 μF
  • Monitoring also with voltage-free mains
  • Measuring circuit L(+)/L(-) with broken wire detection (can be switched off)
  • Protective conductor PE1/PE2 with broken wire detection (can't be switched off)
  • With galvanic separated Modbus RTU interface


  • 2 separate adjustable response thresholds (using e.g. for pre-alarm and Alarm)
  • Setting range of 1st response value (Pre-alarm): 20 kΩ … 500 kΩ
  • Setting range of 2nd response value (alarm): 1 kΩ … 100 kΩ
  • 1 changeover contacts each for insulation failures-Pre-alarm and -alarm
  • Energized or de-energized on trip can be selected for indicator relay
  • With multicolour status LED to indicate the state of operation.
  • Automatic and manual device self-test
  • Alarm storage selectable
  • Protection against manipulation by sealable transparent cover
  • External control input for combined test- / reset-button with additional Stop of the measuring function
  • 2 wide voltage input for auxiliary voltage
  • Width 52.5 mm