ISOLGUARD insulation monitoring device HIG24VDC

The insulation monitoring device ISOLGUARD HIG24VDC produced by HAKEL is designed for monitoring the insulation status of direct current IT power supply systems with a nominal voltage of 24V DC. The device continuously monitors the insulation state of the positive and negative output of an insulation power supply system against the base point. For stationary devices it is usually PE conductor. The potential free switching contact of the signalization relay will switch during the insulation resistance decrease of + or – output. A fault is also indicated by LEDs on the front panel.
The insulation monitoring device is equipped to display the numeric values of the measured insulation resistance. The measured resistance value of the positive and negative output of a controlled network is displayed on the device´s screen. There are buttons for setting the parameters of the insulation monitoring device and signalling LEDs to display the status of the controlled network and
the device itself. It is possible to connect the insulation monitoring device to the panel MDS-D equipped with a touchscreen by means of the RS485 busbar. The MDS-D panel displays the actual measured values and the actual insulation monitoring device setting. HIG24VDC can communicate with the master computer via the RS485 busbar with the protokol derived from the PROFIBUS protocol.

Only one insulation monitoring device can be connected to the same ungrounded IT power supply system.


Basic characteristics 

• The monitor for insulating statuses of DC systems with the voltage 24 V DC
• Displaying the measured values of the positive and negative output of a controlled network on the device‘s screen
• Two signalling relays of the IMD status and status of monitored system
• Optional memory of the alarm called with the option to unblock with the button on the insulation monitoring device
• Connection to the RS485 busbar, insulation strengthe 2500 V against internal circuits and network circuits
• Option to set the critical values, hysteresis values and other parameters using the insulation monitoring device buttons
• Access to setting the insulation monitoring device by button can be locked, the insulation monitoring device is unlocked by a combination of buttons
• Module for assembly on the DIN rail 35 mm with the total width 2M (36 mm)

Dimension drawing
Dimension drawing
Installation diagram
Installation diagram Počet fotek v galerii: 2
Maximum IT power supply system operating voltage (without external inductor) Un 12 ÷ 28 V DC
Power consumption P max. 2 VA
Internal impedance of the measuring input Zi > 200 kΩ
Displayed value’s range Risol 5 kΩ ÷ 900 kΩ
Measuring accuracy ± 10%
Critical insulation resistence Rcrit adjustable 5 kΩ ÷ 500 kΩ
Insulation resistance hysteresis Rhyst adjustable 0 ÷ +100% Rcrit
Delay in response of signalling tON adjustable from 0 to 60 sec, with a 1 sec step
Signalling relay KA1. Potential-free switching contact / Electric strength to the internal circuits and to the supply circuits 250 V AC / 1A / 3750 Vrms
Signalling relay KA2. Potential-free switching contact. Electric strength to the internal circuits and to the supply circuits 250 V AC / 1A /3750 Vrms
Communication line: RS485 type MASTER-SLAVE, 9600 Bd, even count parity / Insulating strength to the internal circuits and to the network circuits 2500 Vrms
General data
Degree of protection according to IEC 60529 IP20
Weight m 110 g
Housing material PA-UL94 V0
Method of assembly DIN rail 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 61326-2-4
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 70 933
Installation instructions (850.96 KB)
2D model (728.74 KB) for registered only
3D model (469.2 KB) for registered only
EC declaration of conformity (83.77 KB) for registered only