Why Choose the ABB A42 112-100 Single-Phase Energy Meter?
The ABB A42 112-100 is a professional single-phase transformer-connected electricity meter designed for accurate active-energy monitoring in commercial, residential and industrial electrical installations. Part of ABB's A42 DIN-rail mounted EQ meter range, it is designed for indirect measurement using an external current transformer, making it suitable for circuits where direct-connected metering is not appropriate.
The A42 112-100 provides Class B / Class 1 active-energy accuracy and operates across a wide 57.7–288 V AC voltage range at 50/60 Hz. Its transformer-connected input supports a meter current of up to 6 A, while the meter can also display useful electrical instrumentation values including voltage, current and frequency.
A key feature of this model is its integrated RS-485 communication interface supporting Modbus RTU and ABB EQ Bus. Together with its electrical pulse output, infrared communication capability, alarm functionality, LCD display and MID approval, the A42 112-100 provides a practical solution for connected single-phase energy monitoring and sub-metering.
Key Advantages
- Professional single-phase CT-connected electricity metering.
- Class B / Class 1 active-energy accuracy for dependable energy measurement.
- Integrated RS-485 communications for remote meter reading and system integration.
- Supports Modbus RTU and ABB EQ Bus communication protocols.
- Wide 57.7–288 V AC operating voltage range.
- 6 A maximum meter current for transformer-connected measurement.
- Measures active energy together with useful electrical instrumentation values.
- Electrical pulse output supports external energy-monitoring equipment.
- Compact 4-module DIN-rail format simplifies panel installation.
- MID approved for compliant electricity-metering applications.
Key Features
- ABB A42 series single-phase electricity meter.
- Steel functionality level.
- Transformer-connected current measurement.
- 6 A maximum current.
- 57.7–288 V AC operating voltage.
- 50/60 Hz operating frequency.
- Class B / Class 1 active-energy measurement.
- Single-tariff energy metering.
- Voltage, current and frequency instrumentation.
- RS-485 communication interface.
- Modbus RTU / ABB EQ Bus communication.
- Electrical S0 pulse output.
- Infrared communication capability.
- Alarm functionality for electrical monitoring.
- Backlit 7-digit LCD display.
- IP20 degree of protection.
- Compact 4 DIN-module construction.
CT-Connected Single-Phase Metering with RS-485 Communications
The ABB A42 112-100 uses an external current transformer to provide indirect measurement of single-phase electrical circuits. This arrangement enables energy consumption to be monitored while the meter operates from the transformer's secondary current, making the A42 112-100 suitable for installations where direct connection of the full load current is impractical.
Integrated RS-485 communication with Modbus RTU and ABB EQ Bus enables active-energy and supported instrumentation data to be collected remotely by compatible supervisory, building-management and energy-management systems. Combined with its pulse output, alarm functions and infrared capability, the A42 112-100 provides flexible integration for automated meter reading and professional energy monitoring.
Typical Applications
- Commercial single-phase energy monitoring.
- Residential electricity sub-metering.
- Industrial single-phase electrical loads.
- CT-connected electrical circuits.
- Distribution boards and control panels.
- RS-485 Modbus RTU energy-monitoring networks.
- Building-management and automation systems.
- Energy-management and consumption-monitoring systems.
- Plant and machinery energy monitoring.
- MID-compliant active-energy metering applications.
