The A-ISOMETER® of the IRDH375(B) series is designed to monitor the insulation resistance of unearthed main circuits (IT systems) AC, AC/DC 0…793 V resp. DC 0…650 V. The AMP^Plus measuring principle meets the particular requirements of modern power supplies which often include rectifiers, converters, thyristor-controlled DC drives and directly connected DC components. In these systems often high leakage capacitances against earth occur due to interference suppression measures. The IRDH375(B) automatically adapts itself to the existing system conditions.
In combination with a coupling device, the Isometers can also be used for higher voltages. An external supply voltage allows de-energized systems to be monitored too.

• Insulation monitoring for unearthed sys­tems
  AC, AC / DC 0…793 V, DC 0…650 V
• Nominal voltage extendable via coupling device
• Two separately adjustable response values
  1 kΩ…10 MΩ
• AMPPlus measuring principle
• Automatic adaptation to the system leakage capacitance
• Info key to display device settings and the system leakage capacitance
• Continuous self monitoring, with automatic alarm message
• Automatic self test, selectable

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