The ISOMETER® of the IR425 series is designed to monitor the insulation resistance of un­earthed AC/DC control circuits (IT systems) 0…300 V. DC components existing in AC/DC systems do not influence the operating characteristics. An external supply voltage allows de-energized systems to be monitored too.

Characteristics of ISOMETER® IR425

• Insulation monitoring for AC/DC control circuits 0…300 V
• Two separately adjustable response values
• Preset function (automatic setting of basic parameters)
• Connection monitoring system/earth
• LEDs: Power On, Alarm 1, Alarm 2
• Internal/external test/reset button
• Two separate alarm relays (one changeover contact each)
• N/O or N/C operation, selectable
• Fault memory behaviour, selectable
• Self monitoring with automatic alarm
• Multi-functional LC display
• Adjustable response delay
• Two-module enclosure (36 mm)
• Push-wire terminal (two terminals per connection)