Deye Smart Energy Meter Single Phase

The DEYE Energy Meter Single Phase is a compact metering solution for single-phase energy monitoring, available from Solar Rains in two configurations: SDM120CTM-40mA and SDM120CTM-40mA (ID 02) for AC couple applications.

The meter is designed around 40mA secondary-output current transformer measurement and is supplied with an ESCT-TA16 split-core CT rated at 120A primary / 40mA secondary. This configuration provides a practical way to measure electrical energy while keeping the meter itself compact enough for installation inside distribution boards and electrical enclosures.

The meter supports measurement of key electrical parameters including voltage, current, active power, reactive power, apparent power, power factor, frequency, and total/import/export energy. Its bi-directional measurement capability allows energy flowing into and out of an installation to be monitored, making it particularly relevant to solar PV and energy management applications.

For system communication, the meter features a 2-wire RS485 interface with Modbus RTU protocol. This allows measured data to be read by compatible monitoring and energy management equipment. With its 18mm-wide, one-module DIN rail format, the meter is designed to provide these functions while occupying minimal space inside an electrical board.

Key Features of DEYE Energy Meter Single Phase

40mA CT-Based Measurement

The SDM120CTM-40mA is specifically configured for 40mA secondary-output current transformers. The supplied ESCT-TA16 split-core CT has a 120A primary and 40mA secondary rating, providing a matched CT and meter combination for single-phase measurement.

Bi-Directional Energy Tracking

The meter measures energy in both directions, allowing users to monitor import and export energy. This provides useful visibility where electricity can flow between the installation, connected loads, and the grid.

RS485 Modbus RTU Communication

Built-in RS485 2-wire communication uses the Modbus RTU protocol. The interface supports baud rates from 1200 to 9600 bps, Modbus addresses from 1 to 247, and a response time of less than 100ms.

Compact One-Module DIN Rail Design

With a width of only 18mm, the meter occupies one module on a standard 35mm DIN rail. This compact format is useful where electrical distribution boards have limited available space.

Multifunction Electrical Measurement

The meter provides measurement of voltage, current, active power, reactive power, apparent power, power factor, frequency, and energy values. This gives installers and system operators access to a broad set of electrical operating data from one compact device.

Clear Local Display

The meter incorporates a backlit LCD display for viewing measured electrical parameters directly at the device. This provides a convenient local reference during system operation and inspection.

Two Product Configurations

Solar Rains supplies two versions within this product range:

• DEYE Energy Meter Single Phase — SKU: SDM120CTM-40mA
• DEYE Energy Meter Single Phase (AC Couple ID 02) — SKU: SDM120CTM-40mA (ID 02)

The second configuration is identified specifically for the AC couple ID 02 application.

Technical Highlights

The SDM120CTM-40mA operates with a nominal voltage of 230V AC and an operational voltage range of 176–276V AC. The meter supports both 50Hz and 60Hz operation, while current measurement is performed through the supplied ESCT-TA16 120A/40mA split-core CT. The primary CT ratio can also be configured from 5A to 9999A when used with compatible 40mA CTs.

For measurement accuracy, active energy is specified as Class 1.0 according to IEC 62053-21, while reactive energy is Class 2.0 according to IEC 62053-23. Voltage and current accuracy is specified at 0.5% of range, with frequency accuracy of 0.2% of mid-frequency, power factor accuracy of 1% of unity, and active power accuracy of 1% of range end.

The RS485 communication interface uses Modbus RTU, with selectable communication speeds from 1200 to 9600bps. The meter supports configurable pulse output 1 at 1000, 100, 10 or 1 imp/kWh, while pulse output 2 is fixed at 1000 imp/kWh.

For physical installation, the meter measures 18 × 118 × 64mm and weighs approximately 150g. It is designed for 35mm DIN rail mounting and uses a self-extinguishing UL94V-0 housing material. The front protection rating is IP51 for indoor use, while the terminal protection rating is IP20. Its specified operating temperature is -25°C to +55°C.

The supplied kit includes the SDM120CTM-40mA smart meter, ESCT-TA16 split-core CT, quick start guide & wiring manual, and terminal security seals. The product is supplied with a 24-month warranty.

Main Benefits

For Solar Installers & EPC Contractors

The DEYE Energy Meter Single Phase provides installers with a compact way to add single-phase energy measurement to compatible systems. Its one-module DIN rail format helps save space inside distribution boards, while the split-core CT simplifies current measurement without requiring the meter itself to accommodate the full measured current directly.

RS485 Modbus RTU communication also provides a practical interface for connecting measurement data to compatible monitoring and energy management equipment. The ability to measure both import and export energy provides installers with additional visibility when commissioning and monitoring solar-related systems.

For Solar System Designers

For system designers, the combination of CT-based measurement, multifunction electrical monitoring, and Modbus communication provides flexibility when planning a compact metering arrangement.

The meter can monitor voltage, current, power, frequency, power factor, and energy values, allowing several electrical parameters to be accessed through a single metering device. Its configurable CT primary ratio also provides flexibility when compatible 40mA CTs are used.

For Energy Management Applications

Bi-directional measurement is particularly useful where energy can move in both directions. The meter can track imported and exported energy, providing clearer information about energy flow rather than measuring consumption alone.

This makes the meter suitable for applications involving solar PV monitoring, energy management, and other systems where understanding the direction of energy flow is important.

For Electrical Distributors

The compact form factor and broad measurement capability make the SDM120CTM-40mA a practical metering accessory for electrical and solar system installations.

The product is supplied as a complete kit with the matched ESCT-TA16 CT, allowing customers to receive the principal metering components together rather than sourcing the CT separately.

Installation

The DEYE Energy Meter Single Phase is designed for 35mm DIN rail installation and uses a compact one-module housing. Installation involves mounting the meter, positioning the supplied split-core CT, completing the required electrical and communication connections, and configuring the meter for the application.

Step 1: Prepare the Distribution Board

Select an appropriate position inside the electrical distribution board or enclosure. The meter is intended for indoor installation and requires sufficient space for its 18mm-wide body and associated wiring.

Step 2: Mount the Meter

Secure the meter onto the 35mm DIN rail. Check that it is firmly seated and positioned correctly before proceeding with the electrical connections.

Step 3: Install the CT

Place the supplied ESCT-TA16 split-core CT around the conductor being measured. The supplied CT is rated at 120A primary / 40mA secondary and is matched to the meter’s 40mA CT input.

Step 4: Complete the Electrical Connections

Connect the required voltage and CT wiring according to the supplied wiring instructions. Ensure all terminals are correctly connected and securely tightened before energising the system.

Step 5: Connect RS485 Communication

Where communication with a compatible monitoring or energy management system is required, connect the meter through its 2-wire RS485 interface. The communication protocol is Modbus RTU.

Step 6: Configure the Meter

Set the required communication parameters, including the Modbus address and baud rate, according to the connected system. If required, configure the CT primary ratio for the compatible 40mA CT being used.

Step 7: Check the Measurements

After installation and configuration, use the LCD display and connected monitoring system to verify the measured voltage, current, power, frequency, power factor, and energy readings.

Electrical installation and connection work should be carried out by appropriately qualified personnel and in accordance with the requirements applicable to the installation.

Deye

Ningbo Deye Inverter Technology Co., Ltd. was founded in 2007 and is a subsidiary of the Deye Group. According to Deye, the company operates a manufacturing plant covering more than 15,000m² with production and testing facilities, and specialises in integrated solar PV and energy storage solutions for residential, commercial, and industrial applications.

Deye’s product portfolio includes PV inverters, hybrid inverters, microinverters, energy storage products, and accessory & monitoring solutions. The company states that cumulative Deye inverter shipments exceeded 5 million units by the end of 2025, including 2 million hybrid inverters.

The company’s product and solution portfolio includes both solar generation and energy management technologies, providing the wider ecosystem in which compatible metering and monitoring equipment can be used.