The insulation monitoring device HIG93/CL400 produced by HAKEL for the ISOLGUARD series is designed for monitoring the insulation status of single-phase and 3-phase ungrounded IT power supply systems, is designed and operated according to standards IEC 61010-1:2010, EN 50522, IEC 61936-1:2010.

Device enables monitoring of single-phase and 3-phase ungrounded IT power supplies systems up to the maximum operating voltage 275V AC, eventually 3x275V AC. If the insulation status monitoring of a single-phase or 3-phase IT system with higher operating voltage is required, it is necessary to create an artificial centre using TL* inductors produced by HAKEL. Such a created centre is connected to the terminal of insulation monitoring device HIG93/CL400.

The insulation monitoring device enables to display the numeric value of the measured insulation resistance. Device is equipped with buttons for setting module parameters and with signalling LED diodes to display the status of monitored power supply system and status of the device.

HIG93/CL400 device is equipped with active current loop output 4 ÷ 20 mA, which indicates actual measured insulation resistance value. Current loop is galvanic isolated from the monitored system and from the internal circuit of the device.

Two inbuilt signalling relays with switching contacts enables alarm signalling for two independently set values of critical insulation resistance. The insulation monitoring device has an optional alarm memory function with the option to terminate the alarm using the button on the insulation monitoring device.

Local and remote testing of the insulation monitoring device function can be done.


Basic characteristics

  • Insulation monitoring device for AC systems with 0 to 275 V voltage without additional devices, for greater voltages additional inductor is needed
  • Display of the measured insulation resistance Risol in the range 5 kΩ to 900 kΩ
  • Two insulation resistance status signalling relays equipped with switching contact
  •  Pasiv galvanic isolated current loop 4 ÷ 20 mA for value output of the isolation resistance Risol
  • Adjustable hysteresis of the insulation resistance limit value in the range from 0 to 100 % using the display and push-buttons
  •  Possibility to adjust monitored insulation resistance Rcrit values to: 1 kΩ, 3,5 kΩ, 7,5 kΩ, 22 kΩ, 50 kΩ, 80 kΩ using the display and push-buttons
  • The characteristic of current loop 4 ÷ 20 mA is automatically chosen according to set Rcrit value
  • Adjustable delay in signalling relay response tON in the range from 0 to 60 seconds using the display and push-buttons
  • Access to the IMD parameter setting with the pushbuttons can be locked/unlocked by a button combination
  • Separate supply voltage also allows to monitor IT power supply systems, which are not under voltage
  • 2M (36 mm) width module for assembling on 35 DIN rail
Dimension drawing
Dimension drawing
Installation diagram
Installation diagram
Supply voltage range Us 90 - 264 V AC (47÷63 Hz) or 120 - 370 V DC
Insulation voltage between power supply and internal circuits 3000 V AC
Maximum IT power supply system operating voltage (without external inductor) Un 275 V AC
Power consumption P max. 5 VA
Measuring voltage Um 24 V DC
Measuring current Im < 1 mA
Internal resistance of the measuring input Zi > 1 MΩ
Displayed value’s range Risol 5 kΩ - 900 kΩ
Measurement accuracy 5 kΩ … 10 kΩ 2 kΩ
Measurement accuracy 10 kΩ … 900 kΩ ± 10%
Critical insulation resistence Rcrit adjustable 1 kΩ / 3,5 kΩ / 7,5 kΩ / 22 kΩ / 50 kΩ / 80 kΩ
Insulation resistance hysteresis Rhyst adjustable 0 - +100% Rcrit
Delay in response of signalling tON adjustable 0 - 60 sec, with a 1 sec step
Potential-free outputs
Signalling relay KA1. Potential-free switching contact / Electric strength to the internal circuits and to the supply circuits 230 V AC / 1A / 3750 Vef
Signalling relay KA2. Potential-free switching contact. Electric strength to the internal circuits and to the supply circuits 230 V AC / 1A / 3750 Vef
Current loop
Current output type Isolated passive current loop
Insulating strength against internal circuits and network circuits 3 kV AC
Maximum load resistor of the loop 500 Ω (power supply from a 24V DC source inside the module)
Operating range of insulation status value signalling 4 - 20 mA
Maximum range of current output 0 - 25 mA
Uncertainty of Risol value signalling – Typ. < 1 %
Uncertainty of Risol value signalling – Max. ± 5 %
General data
Degree of protection according to IEC 60529 IP20
Weight m 160 g
Housing material PA-UL 94 V0
Method of assembly on the bar DIN 35
Recommended section of the connected conductors S 1 mm2
Operating conditions
Operating temperature ϑ -10°C - +60°C
Atmospheric pressure 86 - 106 kPa
Operating position any
External magnetic and electric field according to IEC 61326-24
Overvoltage category / testing voltage III, according to IEC 60664-1:2007
Pollution degree 2, according to IEC 60664-1:2007
Operational mode permanent
Article number 70 932
2D model (728.74 KB) for registered only
3D model (469.21 KB) for registered only