Device Features
The ISOMETER® IR423 is designed for insulation monitoring in mobile generators with AC voltages ranging from 0 to 300 V. It offers protection through electrical separation, features a version 'W' for high mechanical stress, and includes two adjustable response values. The device has a connection monitoring system, power and alarm LEDs, test/reset buttons, and two alarm relays with selectable operation modes. It also includes a multi-functional LC display and adjustable response delay.

Product Description
The IR423 series monitors the insulation resistance of unearthed AC systems supplied by mobile generators. It is suitable for systems with frequencies ≥ 30 Hz and directly connected DC circuits, with a maximum system leakage capacitance of 5 µF.

Application
The device is applicable in electrical installations in mobile units, low-voltage generating sets, and mobile auxiliary power generators on pipeline sites. It complies with standards such as IEC 60364-7-717 and DIN VDE 0100-551.

Function
The insulation resistance is displayed on the LC screen, allowing for easy recognition of changes. If resistance falls below preset values, alarm relays activate after a response delay. The device can distinguish between prewarning and alarm states, and the fault memory can retain alarms until reset.

Connection Monitoring
Connections to the system and earth are checked automatically or manually. Faults trigger alarm relays and display error messages. Faults can be reset automatically or manually.

Measurement Method
The IR423 uses a modified measurement method suitable for mobile generators, including inverter technology.

Standards
The device meets standards such as DIN EN 61557-8, IEC 61557-8, and ASTM F1669M-96.

Technical Data
The device supports a rated insulation voltage of 250 V and a rated impulse voltage of 4 kV. It operates with supply voltages of AC 16-72 V/DC 9.6-94 V or AC/DC 70-300 V, with a frequency range of 30-460 Hz. The response values for alarms are adjustable between 1-200 kΩ.

Environmental and Mechanical Conditions
The device operates in temperatures from -25 to +55 °C, with an option for -40 to +70 °C. It is classified under various climatic and mechanical conditions standards.

Connection and Mounting
The device can be connected using screw-type or push-wire terminals and mounted on a DIN rail or with screws. It has a degree of protection of IP30 for internal components and IP20 for terminals.

Ordering Information
Different models are available with varying supply voltage specifications and terminal types. Accessories include mounting clips for screw mounting.