ACREL DC Insulation Resistance Monitor with Relay Alarms
ACREL DC Insulation Resistance Monitor with Relay Alarms provides online monitoring of insulation resistance in ungrounded DC systems from 10 to 1000 volts. Available in low-voltage and high-voltage versions, it monitors DC voltage and insulation resistance while providing configurable warning and alarm functions. With LCD and LED indication, three relay outputs and RS485 Modbus-RTU communication, it is suited to DC power distribution, UPS, EV charging, photovoltaic and energy storage applications.
The ACREL DC Insulation Resistance Monitor with Relay Alarms is designed for online insulation monitoring in DC systems where the positive and negative terminals are ungrounded. Continuous monitoring helps identify declining insulation resistance so that an alarm can be generated before an insulation fault becomes a more significant problem.
The monitor uses an unbalanced bridge principle. According to Acrel, this approach avoids the limitation of balanced bridge monitoring when ground faults occur at both the positive and negative poles.
Two voltage versions are available. The AIM-D100-TL is specified for 10-100 volts DC systems, while the AIM-D100-TH is specified for 100-1000 volts DC systems.
How it works
- Continuously monitors insulation resistance between the positive and negative DC poles and ground.
- Monitors the voltage between the positive and negative poles and the corresponding pole-to-ground voltages.
- Provides configurable warning and alarm functions when insulation resistance falls below the set value.
- Monitors for DC overvoltage and undervoltage conditions.
- Displays alarm status through the LCD and LED indicators and provides relay outputs.
- Provides RS485 communication using the Modbus-RTU protocol for integration with compatible monitoring systems.
Why choose this product
- Covers a broad range of ungrounded DC applications through two voltage versions.
- Provides both insulation resistance and DC voltage monitoring in one device.
- Offers relay outputs for external alarm or control circuits.
- Supports RS485 Modbus-RTU communication for system monitoring.
- DIN-rail installation makes it suitable for electrical control and monitoring panels.
Benefits
- Helps identify insulation resistance deterioration in ungrounded DC systems.
- Provides local visual indication through LCD and LED indicators.
- Allows warning and alarm thresholds to be configured within the specified range.
- Records up to 20 fault records.
- Provides selectable normally open or normally closed relay outputs.