Dold Industries Ltd

11 Hamberts Rd. Blackall Ind. Estate
South Woodham Ferrers
GB-Essex, CM3 5UW
LK 5896/900

Insulation monitor

LK 5896/900


Auxiliary voltage

Alarm value

Prewarning value

Approvals and Markings


  • 0066991
  • LK5896.13/900/61 DC24V 1k-250k
The insulation monitor LK 5896/900 of the VARIMETER IMD family is a solution for optimal... more

Product description

The insulation monitor LK 5896/900 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 even with large leakage capacity to earth (PE). By using a trigger input and a trigger output 2 separate IT systems can be coupled and monitored during operation without the problem that the 2 insulation monitors disturb each other. The adjustment of the setting values is simple and user friendly done on 2 rotary switches on the front of the device. Via LEDs the measured value, device parameters and device status are indicated easy to read. The unit has 3 relay contacts to signal Insulation and device failures. The analogue output provides a voltage and current signal proportional to the actual insulation resistance, which can be connected to a superior control (plc), another system or external display unit.

Technical specifications

Width: 90 mm
Response value: 1 - 250 kΩ
IMD type: AC, DC, AC/DC
Nominal voltage IT system: AC 0 - 1000, DC 0 - 1000 V
Auxiliary voltage: DC
Earth fault indicator: Yes
Approvals: UL
Connection for indicator: Yes
Response value type: Adjustable
Enclosure design: Switch cabinet
Type: LK 5896/900


  • Preventive fire and system protection
  • System for sequential monitoring of separated voltage systems, that can be coupled
  • Quick fault localisation through selective earth fault detection to L+ and L-
  • Universal application in non-earthed AC, DC, AC/DC networks with up to 1000 V nominal voltage
  • Suitable for large leakage capacitances up to 3000 μF
  • Simplest setting via engaging rotary switches
  • Optimised measuring times - normally shorter than with known methods
  • Monitoring also with voltage-free mains
  • Measuring circuit with broken wire detection
  • No additional coupling device required
  • Analogue output for value of the insulation resistance: 0 ... 10 V / 0 ... 20 mA (2 ... 10 V / 4 ... 20 mA)


  • Insulation monitoring according to IEC/EN 61557-8
  • Detection of symmetric and asymmetric insulation faults
  • 1 changeover contact each for prewarning and alarm
  • 3. output relay for signalling wire break and device faults
  • Prewarning threshold setting range: 20 kΩ ... 2 MΩ
  • Alarm threshold setting range: 1 kΩ ... 250 kΩ
  • Energized or de-energized on trip can be selected for output relay
  • Setting the maximum leakage capacitance to shorten the response time
  • Simple, clearly arranged adjustment of the device with screwdriver
  • LED chain to indicate the current insulation resistance
  • Display " measuring circuits active"
  • Display "Master" or "Slave"
  • Automatic and manual device self-test
  • Alarm storage selectable
  • External test and reset pushbutton can be connected
  • With watchdog timer to monitor the trigger signal
  • Width: 90 mm