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LK 5896

Insulation monitor

LK 5896


Auxiliary voltage

Alarm value

Prewarning value

Approvals and Markings


  • 0065131
  • LK5896.13/100/61 DC24V 1k-250k
The insulation monitor LK 5896 of the VARIMETER IMD family is a solution for optimal insulation... more

Product description

The insulation monitor LK 5896 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). 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. In addition the LK 5896 provides a second measuring circuit that can be used to monitor an inverter on the AC side also when the inverter is disconnected.

Technical specifications

Width: 90 mm
Classification: For photovoltaic systems
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


  • Preventive fire and system protection
  • 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
  • For monitoring photovoltaic system, also with thin-film technology
  • Optimised measuring times - normally shorter than with known methods
  • Monitoring also with voltage-free mains
  • Additional measuring circuit allows AC output monitoring even with the inverter switched off, e.g. with hybrid vehicles
  • Measuring circuit with broken wire detection
  • No additional coupling device required
  • Trigger output for insulation fault locating system
  • 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
  • Measuring circuits can be disconnected via control terminals, e.g. for mains couplings
  • 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 of active measuring circuits
  • Automatic and manual device self-test
  • Alarm storage selectable
  • External test and reset pushbutton can be connected
  • Width: 90 mm