The ISOMETER® IR420 monitors the insulation resistance of unearthed AC control circuits (IT systems) 0…300 V. If the systems to be monitored include DC components, such as switched-mode power supplies or solenoid valves, the display and operating characteristics may be affected.
The display and response values apply to pure AC systems. An external supply voltage allows de-energised systems to be monitored too.

Characteristics of ISOMETER® IR420

• Insulation monitoring for IT control circuits AC 0…300 V
• Two separately adjustable response values
• Preset function (automatic assignment 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 message
• Multi-functional LC display
• Adjustable response delay
• Two-module enclosure (36 mm)
• RoHS-compliant
• Push-wire terminal (two terminals per connection)