Innovatieve technologieën voor veilige omgang met elektriciteit voor hoge beschikbaarheid

We offer you first-class quality and safety combined with global service and every support in resolving your monitoring problems.



- Deze apparaatserie bevindt zich in de uitdovingsfase. -
Leverbaar volgens beschikbaarheid tot 31.12.2023

Uw persoonlijke contactpersoon helpt u graag.


  • Insulation monitoring for unearthed AC, AC/DC systems 0…793 V, DC 0…650 V
  • Nominal voltage extendable via coupling device
  • Two separately adjustable response values 1 kΩ…10 MΩ
  • AMPPlus measurement method
  • Automatic adaptation to the system leakage capacitance
  • Info button to display device settings and the system leakage capacitance
  • Continuous self monitoring, with automatic alarm message
  • Automatic self test, selectable
  • Connection for external kΩ indication
  • Test and reset button
  • Connection external test and reset button
  • Two separate alarm relays with two potential-free changeover contacts
  • N/O or N/C operation
  • Alarm relay for system fault (N/C operation)
  • Backlit LC display
  • RS-485 interface
  • Plug-in terminals


  • AC, DC or AC/DC main circuits
  • AC/DC main circuits with directly connected DC components, such as rectifiers, converters, and thyristorcontrolled DC drives
  • UPS systems, battery systems
  • Heaters with phase control
  • Installations including switch-mode power supplies
  • IT systems including high leakage capacitances
  • Coupled IT systems

ISOMETER® IRDH375 Variant(en)

TypeNominal voltage UnSupply voltage USArt. No.
IRDH375-435AC 0…793 V / DC 0…650 V*AC 88…264 V / DC 77…286 V*B91065000
IRDH375-427AC 0…793 V / DC 0…650 V*DC 19.2…72 V*B91065002
IRDH375B-435AC 0…793 V / DC 0…650 V*AC 88…264 V / DC 77…286 V*B91065004
IRDH375B-427AC 0…793 V / DC 0…650 V*DC 19.2…72 V*B91065006

* absolute values
Device “Option-W” with increased shock and vibration resistance: Indicated by the letter “W” at the end of the order number

Optionele accessoires voor ISOMETER® IRDH375

External kΩ measuring instruments (400 µA)

TypeSKMP *2)Art. No.
7204-1421120 kΩB986763
9604-1421120 kΩB986764

*2) SKMP = scale centre point

External kΩ measuring instrument 20 mA

TypeArt. No.

Transparent front plate cover IP65

TypeArt. No.
144 x 72B98060005

Coupling devices

TypeNominal system voltage UnArt. No.
AGH150W-4DC 0…1760 VB98018006
AGH204S-4AC 0…1300 V / 0…1650 VB914013
AGH520SAC 0…7200 VB913033

Downloads voor ISOMETER® IRDH375

CE Conformiteitsverklaringen IRDH275 - 375 - 575 95.8 KB 2022/08/12 06:17:2512.08.2022 06:17:25
Handboeken IRDH375/IRDH375B 4.1 MB DE2022/06/09 10:46:1309.06.2022 10:46:13D00124
Handboeken IRDH375/IRDH375B 4.0 MB EN2022/06/09 10:48:0509.06.2022 10:48:05D00124
Handboeken IRDH375/IRDH375B 595.9 KB ES2019/05/13 10:31:5413.05.2019 10:31:54D00124
Handboeken IRDH375/IRDH375B 1.4 MB FR2019/05/13 10:31:5413.05.2019 10:31:54D00124