SPM02R FLEX

Applies to: SPM02R FLEX | Hardware Revision: V3.0+ | Last Updated: 2026-07-18

1. Introduction

Built for advanced 3-phase applications, the SPM02R Miniature Energy Meter (Flexible Version) is ideal for installation above or below circuit breakers, requiring no DIN-rail space. Equipped with a reliable Modbus RTU (RS485) interface, it guarantees stable, accurate data collection via a robust wired connection.

Product Highlights

Space saving: Fits easily into new or existing power distribution boards without taking DIN-rail space
Real-time Monitoring: Tracks voltage, current, power, and energy for efficient management
Large Aperture: Supports cable sizes up to 16mm² with a 9.6mm aperture for maximal 63A measurement.
Accurate Metering: Delivers accurate active energy measurements with a tolerance of 1%, ensuring precise monitoring of energy consumption.
Isolated Connectivity: Features a 4kV isolated Modbus RTU (RS485) interface for safe, stable, and interference-free integration.

Typical Applications

Energy management systems (EMS) for buildings, Infrastructure, and Industry

2. Part Description

Element

Description

Cable for X connection

Connect to power supply from Line

Cable for Y connection

Connect to power supply from Line

Cable for Z connection

Connect to power supply from Line

Cable for N connection

Connect to power supply from Neutral (N)

Through-hole for X wire

Through-hole for X wire: Ensure the wire (X) passes through the hole.

Through-hole for Y wire

Through-hole for Y wire: Ensure the wire (Y) passes through the hole.

Through-hole for Z wire

Through-hole for Z wire: Ensure the wire (Z) passes through the hole.

Reset button

Press and hold for above 5 seconds to reset communication settings to default.

LED indicator

Shows device operation and network status through different flashing patterns.¹⁾

Current flow direction

Indicates forward / positive power flow for installation

Product model

Refer to the 'Ordering Information' section for product selection.

RS485 communication wire

White wire: RS485-A Blue wire: RS485-B

Remark:

1) Refer to the user guide of your selected models for detailed LED status indicators.

3. Technical Data

Parameter

Specification

Rated operating voltage U_n

220-240 VAC (L-N), 50/60 Hz 380-415 VAC (L-L), 50/60 Hz

Max monitoring current I_max

63 A

Over-voltage category

III

Rated insolating voltage U_i

440V

Rated impulse withstand voltage Uimp

4kV

Pollution degree

Protection degree

IP20

Energy measurement accuracy

±1%

Maximum Power consumption

≤ 2VA

Rated operating temperature

-25°C to 55°C

Size: Height x Width x Depth

46.4x53.0x21.3mm

Integrated communication option¹⁾

Modbus RTU (RS485)

4. Mechanical Outline

Dimension: Unit in mm

5. Electrical Installation

Wiring Diagram

⚠️ Safety Remarks:

The device must be associated with easily accessible upstream protective devices ‒ such as miniature circuit breakers (MCB).
The device must be installed, operated, serviced, and maintained ONLY by qualified professionals.
Please read the user guide carefully before installation for detailed wiring diagrams and safety precautions.

The device comes with 400mm twisted white (RS485-A) and blue (RS485-B) wires. For long-distance RS485 communication, it is recommended to trim these wires short and splice them to a standard shielded twisted-pair cable.

Wiring with 3PN/4P Circuit Breaker (3P4W System)

Wiring with 3-Pole Circuit Breaker (3P4W System)

Forward Energy Calculation: The energy flowing in the same direction as the energy flow arrow printed on the sensor housing is counted as forward energy.

Installation Video

🚧Coming soon...

6. User Interface

Reset Button

Press and hold for above 5 seconds to reset communication settings to the following factory default:

Modbus Address: 247
Baud Rate: 9600 bps
Data Format: N, 8, 1 (No parity, 8 data bits, 1 stop bit)

LED Indicator

Flashing at 1Hz

Data transmitting - Flashes 3 times per exchange. Flashes continuously if polling interval is <3s.

Flashing at 0.25Hz

Standby (No data exchange)

Flashing at 1Hz

Fault Alarm - Fault detected. Please check wiring and power supply.

7. System Integration

The Modbus RTU (RS485) version utilizes a standard, open industrial communication protocol. It can be directly integrated into a wide range of third-party systems, including PLCs, edge gateways, data loggers, SCADA, and Building Management Systems (BMS). Unlike cloud-dependent versions, it operates entirely locally and requires a wired connection to a Modbus master device to poll and collect data. For register maps and communication parameters, please refer to the provided Modbus protocol documentation.

Device Commissioning

To integrate the meter into your RS485 network, you can configure the Modbus address using one of the following two methods:

Method 1: Point-to-Point Configuration (Default Settings) Connect a single device to your master device and configure it using the factory default settings (Modbus Address: 247, Baud Rate: 9600 bps, N, 8, 1). You can reset the device to these defaults at any time by pressing and holding the Reset button for over 5 seconds.

Method 2: Broadcast Address Assignment (Button Triggered) This feature allows for quick commissioning of multiple devices on the same bus without needing to wire and configure them one by one.

Send this command to Broadcast Address 0:

Address (DEC)

Address (HEX)

Description

Func Code

R/W

Data Type

Write Value

30000

0x7530

Assign Modbus Address (Button Triggered)

2× UINT16

0x55AA + [New Address]

How to use Broadcast Address Assignment:

The Host PLC sends a broadcast write command (Slave ID = 0) to register 30000.
The payload must be 2 words (4 bytes): 0x55AA followed by the [New Address] (e.g., 0x0005).
Action: Only the meter that currently has its physical reset button pressed will accept this command and update its address. All other meters on the bus will ignore it.