Dold Industries Ltd

11 Hamberts Rd. Blackall Ind. Estate
South Woodham Ferrers
GB-Essex, CM3 5UW
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 provides best and up to date... more

Product description

The insulation monitor LK 5896 of the varimeter IMD family provides best and up to date insulation monitoring of modern IT systems in an optimum and state of the art way, fulfilling the relevant standards. 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