2CMA170510R1000 ABB A42 112-100 CT-Connected Single-Phase RS-485 Modbus Energy Meter
ABB A42 112-100 is a DIN-rail mounted single-phase transformer-connected active-energy meter with Class B / Class 1 accuracy, a 6 A maximum meter current, RS-485 Modbus RTU and EQ Bus communications, electrical pulse output and MID approval.
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.
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.
Tick the specs you need, then view products that match.
MID Approval
Yes
Measurement Connection Type
Via CT (/5 A)
Device Type
Energy meter
Series
A42
ABB type designation
A42 112-100
ABB order code
2CMA170510R1000
EAN / GTIN
7392696705103
Product group
DIN Rail Mounted Meters
Product type
Single-phase electricity / energy meter
Functionality level
Steel
Connection type
Transformer connected (CT)
Number of phases
1
Maximum meter current
6 A
Operating voltage
57.7–288 V AC
Operating frequency
50/60 Hz
Active-energy accuracy
Class B / Class 1
Energy measurement
Active energy
Tariff type
Single tariff
Communication interface
RS-485
Communication protocols
Modbus RTU / ABB EQ Bus
Output
Electrical S0 pulse output
Number of outputs
1
Number of inputs
2
Display
Backlit 7-digit LCD
Protection rating
IP20
Operating temperature
-40 to +70 °C
Width
70 mm
Depth
65 mm
DIN-rail width
4 modules
Main circuit conductor capacity
0.5–10 mm²
Mounting type
DIN rail
Net weight
approx. 0.20 kg
Approval
MID approved; IEC approved
Standards
IEC 62052-11; IEC 62053-21; EN 50470-1; EN 50470-3
Frequently Asked Questions
What is the ABB A42 112-100 used for?
The ABB A42 112-100 is a single-phase transformer-connected electricity meter used for accurate active-energy measurement and electrical monitoring in residential, commercial and industrial applications.
Is the ABB A42 112-100 a CT-connected meter?
Yes. The A42 112-100 is designed for indirect single-phase measurement using an external current transformer and supports a maximum meter current of 6 A.
What communication protocols does the ABB A42 112-100 support?
The A42 112-100 incorporates an RS-485 interface supporting Modbus RTU and ABB EQ Bus for integration with compatible remote meter-reading and energy-management systems.
What voltage range does the ABB A42 112-100 support?
The meter supports a single-phase operating voltage range of 57.7–288 V AC and operates at 50/60 Hz.
Is the ABB A42 112-100 MID approved?
Yes. The ABB A42 112-100 is MID approved and provides Class B / Class 1 active-energy accuracy for professional electricity-metering applications.
Trusted CT-Connected Energy Metering from ABB
ABB A42 DIN-rail electricity meters combine accurate transformer-connected single-phase energy measurement with practical instrumentation and flexible communications. The A42 112-100 adds RS-485 Modbus RTU and EQ Bus connectivity, pulse output functionality and Class B accuracy for professional energy-management and sub-metering applications.
MID Approval
Yes
Measurement Connection Type
Via CT (/5 A)
Device Type
Energy meter
Series
A42
ABB type designation
A42 112-100
ABB order code
2CMA170510R1000
EAN / GTIN
7392696705103
Product group
DIN Rail Mounted Meters
Product type
Single-phase electricity / energy meter
Functionality level
Steel
Connection type
Transformer connected (CT)
Number of phases
1
Maximum meter current
6 A
Operating voltage
57.7–288 V AC
Operating frequency
50/60 Hz
Active-energy accuracy
Class B / Class 1
Energy measurement
Active energy
Tariff type
Single tariff
Communication interface
RS-485
Communication protocols
Modbus RTU / ABB EQ Bus
Output
Electrical S0 pulse output
Number of outputs
1
Number of inputs
2
Display
Backlit 7-digit LCD
Protection rating
IP20
Operating temperature
-40 to +70 °C
Width
70 mm
Depth
65 mm
DIN-rail width
4 modules
Main circuit conductor capacity
0.5–10 mm²
Mounting type
DIN rail
Net weight
approx. 0.20 kg
Approval
MID approved; IEC approved
Standards
IEC 62052-11; IEC 62053-21; EN 50470-1; EN 50470-3
Free UK delivery on orders over £200 ex VAT. Order in-stock items before 2pm Monday to Friday for next-day delivery.
This productManufacturer Lead Time
Estimated Delivery 6 weeks
Standard delivery
£8 ex VAT · free over £200
UK parcel delivery is £8 ex VAT, or free on orders over £200 ex VAT.
Heavier items may be charged at a weight-based or pallet rate, shown at checkout.
Collect from our showroom
Mon–Fri, 8am–5pm
Order and pay online, then collect from our showroom.
Please allow 15–30 minutes after ordering for us to prepare your order.
Northern Ireland, ROI & export
Priced at checkout
We deliver to Northern Ireland, the Republic of Ireland and overseas.
Delivery is calculated at checkout based on your destination.
Orders with mixed availability
Shipped complete
If part of your order is on a lead time, we hold it and send everything together.
Need the in-stock items sooner? Ask us and we can split the delivery.
Business customer returns
Returns & order support
Need to return an item? Find the guidance for your order below, then contact our team before sending anything back.
Stocked items
Request within 30 days
Changed your mind or ordered the wrong item? Request a return within 30 days of receipt. There is no restocking charge.
Items must be unused, in resalable condition and in their original packaging, and returns need our approval first. Return carriage is at your cost, and the original delivery charge is not refunded.
Faulty or damaged items
Tell us as soon as possible
Faulty, damaged on delivery or the wrong product supplied? Contact our team as soon as possible with the details.
We will review the issue and arrange an appropriate resolution under our terms and conditions and your statutory rights.
Made-to-order items
Manufacturer approval needed
Manufactured, configured and special-order products can only be returned with the manufacturer’s approval. Any handling charge is agreed with you when you request the return.
This does not affect claims for faulty goods or items that do not meet the agreed specification.
Let’s get your return sorted.
Send your order number, product details and reason for return. For faults or delivery damage, include photographs if available. We will confirm the next steps.
The 30-day return request period applies to change-of-mind returns for stocked items. It does not limit your statutory rights for faulty or non-conforming goods.
● Service Agreements
Credit Accounts
Our service agreements are built to support long term procurement relationships. By working closely with engineering teams and procurement departments, we help streamline purchasing processes while ensuring consistent access to critical components and sourcing support when it matters most.
Priority sourcing and supply support
Flexible payment terms for qualifying organisations
Support for engineering, maintenance, and operations
500 +
Stock lines ready to ship
1,000 +
Same day dispatches
3500 +
Customers supported
28
Trusted Manfacturers
● frequently asked questions
Common questions about our products and support
At Led Controls Ltd we help engineers source the right automation and control gear with confidence. below are quick answers to what we are asked most often.
What product ranges do you supply
We supply all leading manfacturers in our industry. we offer next day delivery on most poplour products.
Can you help specify the correct part?
Your content goes here. Edit or remove this text inline or in the module Content settings. You can also style every aspect of this content in the module Design settings and even apply custom CSS to this text in the module Advanced settings.
Do you have stock for urgent orders?
Your content goes here. Edit or remove this text inline or in the module Content settings. You can also style every aspect of this content in the module Design settings and even apply custom CSS to this text in the module Advanced settings.
What are your delivery times and costs?
Your content goes here. Edit or remove this text inline or in the module Content settings. You can also style every aspect of this content in the module Design settings and even apply custom CSS to this text in the module Advanced settings.
What about warranties, returns and faulty items?
Your content goes here. Edit or remove this text inline or in the module Content settings. You can also style every aspect of this content in the module Design settings and even apply custom CSS to this text in the module Advanced settings.
LED Controls is a specialist distributor of factory automation and industrial controls, supplying OEMs, machine builders, panel builders and end users throughout the UK and worldwide. As a trusted UK distributor for many of the world’s leading automation manufacturers, we provide industrial control products, technical expertise and bespoke automation solutions backed by outstanding customer service.
2025 has been a big year for LED Controls, and our blog has expanded accordingly. We've covered a wide range of topics across industrial control and factory automation this year. From core technology explainers and new product releases to panel building best practice...
