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RL 5881

Insulation monitor

RL 5881


Auxiliary voltage

Alarm value


  • 0069087
  • RL5881.11 AC/DC24-240V 1K-300K
The insulation monitor RL 5881 of the VARIMETER IMD family is a solution for optimal insulation... more

Product description

The insulation monitor RL 5881 of the VARIMETER IMD family is a solution for optimal insulation monitoring of modern IT systems. The setting of the parameters and the switching values is done by simple and operator friendly rotational switches on front of the device. 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: 35 mm
Response value: 1 - 300 kΩ
IMD type: DC
Nominal voltage IT system: DC 0 - 240 V
Auxiliary voltage: Without, DC, AC/DC
Earth fault indicator: Yes
Response value type: Adjustable
Enclosure design: Distribution board
Type: RL 5881


  • Preventive fire and system protection
  • Detection of symmetric and asymmetric insulation faults
  • For non-earthed DC voltage networks up to 300 V
  • Suitable for large leakage capacitances up to 30 μF
  • Monitoring also with voltage-free mains
  • No additional coupling device required


  • Insulation monitoring according to IEC/EN 61557-8
  • Adjustable response threshold, Setting range: 1 kΩ … 300 kΩ
  • 1 changeover contacts for insulation failure alarm
  • De-energized on trip
  • Energized on trip on request
  • With multicolour status LED to indicate the state of operation
  • Automatic and manual device self-test
  • Manual reset or hysteresis function selectable (programmable via control input)
  • Protection against manipulation by sealable transparent cover
  • Control input for external test and reset-button
  • 2 wide voltage input for auxiliary voltage
  • RL 5881/100 without auxiliary voltage
  • Width 35 mm