The ISOMETER® of the IRDH275 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 AMPPlus 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 IRDH275 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. For door mounting into distribution panels, refer to type IRDH375(B).
Characteristics of ISOMETER® IRDH275
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 values1 kΩ…10 MΩ
AMPPlus measurement method
Automatic adaptation to the system leakage capacitance
Info button to display device settings and system leakage capacitance
Self monitoring with automatic alarm
Automatic self test, selectable
Connection for external kΩ indication
Test and reset button
Connection external test/reset button
Two separate alarm relays with two voltage-free changeover contacts