The A-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.

• Insulation monitoring for control circuits AC / DC 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)

• AC / DC control circuits in the industrial sector, mechanical engineering, power plants, elevators, automation systems etc.
• AC / DC control and auxiliary circuits in accordance with IEC 60204-1 / DIN EN 60204-1 Electrical equipment of machines
• AC / DC auxiliary circuits in accordance with DIN VDE 0100-725 (VDE 0100-725)
• Smaller AC / DC IT systems such as lighting systems, mobile generators