SPM02 FLEX

Applies to: SPM02 FLEX| Hardware Revision: V3.0+ | Last Updated: 2026-05-20

1. Introduction

The SPM02 Miniature Energy Meter (Flexible version) is an advanced electrical monitoring device designed for three-phase applications. With its compact size, it is ideal to installed above or below circuit breakers, requiring no space on Din-rails. The SPM02 offers precise, real-time data collection for energy consumption, ensuring seamless integration into energy management systems.

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.
Seamless Connectivity: Supports Wi-Fi, Zigbee, and BLE, offering a range of connectivity options for integration into home or industrial energy management systems.
Innovative Architecture: Combines a communication SoC with a metering MCU for OEM/ODM firmware customization

Typical Applications

Energy management systems (EMS) for home and small business
Energy management systems (EMS) for buildings, Infrastructure, and Industry
Energy monitoring for HVAC system
Energy monitoring for commercial lighting system

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 the button above 5 seconds to enter the pairing mode

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.

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.

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

6. User Interface

Reset Button

Press and hold for above 5 seconds to enter pairing mode.

LED Indicator

Solid ON

Device connected - the device is online and functioning normally with cloud connectivity.

Flashing at 2Hz

Pairing mode – press and hold the reset button until the LED flashes rapidly.

Flashing at 0.5Hz

Reconnecting to network - the device is attempting to reconnect using saved network settings.

Flashing at 1Hz

Network connected, cloud unreachable - the device is connected to Wi-Fi/Zigbee, but failed to reach the cloud.

Flashing at 0.25Hz

The device failed internal self-check. Please power off, restart, and reconfigure the network settings.

Flashing at 1Hz

Alarm reminder - The device has detected a fault. Please check the wiring and power supply.

Solid ON

Device connected - the device is online and functioning normally with cloud connectivity.

Flashing at 2Hz

Pairing mode – press and hold the reset button until the LED flashes rapidly.

Flashing at 0.5Hz

Reconnecting to network - the device is attempting to reconnect using saved network settings.

Flashing at 1Hz

Network connected, cloud unreachable - the device is connected to Wi-Fi/Zigbee, but failed to reach the cloud.

Flashing at 0.25Hz

The device failed internal self-check. Please power off, restart, and reconfigure the network settings.

Flashing at 1Hz

Alarm reminder - The device has detected a fault. Please check the wiring and power supply.

Solid ON

Zigbee connected, BLE disconnected – the device is connected to a Zigbee network while BLE is turned off or not connected.

Flashing at 2Hz

Pairing mode – press and hold the reset button until the LED flashes rapidly.

Flashing at 0.5Hz

Reconnecting to network - the device is attempting to reconnect both BLE (if available) and Zigbee using saved settings.

Flashing at 1Hz

BLE connected(if available) - the LED flashes at 1Hz whenever BLE is connected, regardless of Zigbee status.

Flashing at 0.25Hz

The device failed internal self-check. Please power off, restart, and reconfigure the network settings.

Flashing at 1Hz

The device has detected a fault. Please check the wiring and power supply.

Solid ON

Wi-Fi connected, BLE disconnected - the device is connected to Wi-Fi while BLE is disconnected.

Flashing at 2Hz

Pairing mode – press and hold the reset button until the LED flashes rapidly.

Flashing at 0.5Hz

Reconnecting to network - the device is attempting to reconnect both BLE and Wi-Fi using saved settings.

Flashing at 1Hz

BLE connected - the LED flashes at 1Hz whenever BLE is connected, regardless of Wi-Fi status.

Flashing at 0.25Hz

The device failed internal self-check. Please power off, restart, and reconfigure the network settings.

Flashing at 1Hz

Alarm reminder - The device has detected a fault. Please check the wiring and power supply.

7. System Integration

Products equipped with different communication SoC firmwares connect to different systems and cloud platforms. Users can select the appropriate version based on their specific application requirements.

The Tuya WiFi version can only be integrated into the Tuya Cloud using Tuya's encrypted MQTT communication. It cannot be directly integrated with any third-party cloud platforms, ecosystems, or gateways. Third-party clouds or edge gateways need to be integrated via Tuya cloud APIs. For details, please refer to Tuya's developer documentation.

Note:

Tuya's strategy for adjusting the cloud data reporting frequency is not fully disclosed. Based on the latest updates as of April 2026, provided the daily data reporting traffic limit is not exceeded, the fastest expected reporting interval will be between 5 to 15 minutes.
Tuya's Smart Life App is user-friendly and straightforward, making it ideal for entry-level smart home users who prefer simplicity and basic energy consumption monitoring.

For standard operation, the Tuya Zigbee version must be integrated with a Tuya gateway, which then connects to the Tuya Cloud via Tuya's encrypted MQTT communication.

Note:

Tuya's strategy for adjusting the cloud data reporting frequency is not fully disclosed. Based on the latest updates as of April 2026, provided the daily data reporting traffic limit is not exceeded, the fastest expected reporting interval will be between 5 to 15 minutes.
There are unofficial methods available on the market to integrate Tuya Zigbee products with third-party gateways or hubs - such as Home Assistant integration via Zigbee2MQTT. However, please be aware of the following potential issues when using these unofficial integration methods:

⚠️Network Congestion: Tuya's proprietary Zigbee data transmission strategy does not bundle data packets. Consequently, high-frequency reporting of the extensive electrical data types from several energy meters, which generate significantly more data than typical smart home Zigbee devices, can easily cause Zigbee network congestion.
⚠️Security Risks: Integrating with third-party Zigbee gateways using the default global Trust Centre Link Key “ZigbeeAlliance09” poses potential information security risks. Therefore, using non-Tuya gateways in commercial projects is highly discouraged. For third-party gateway integration, the Standard Zigbee 3.0 version with Install Code is strongly recommended.

The Standard Zigbee 3.0 version can seamlessly connects to third-party gateways. Thanks to the standardized application-layer integration of Zigbee 3.0, it is highly convenient and widely applicable for both residential and commercial building projects.

Currently supported smart home ecosystems include:

Home Assistant: Integration via Zigbee2MQTT (SPM01, SPM02, SDM01, and SDM02)
SmartThings: Integration via the SmartThings Hub driver (officially approved).
Homey: Integration via the Bituo Technik App

You can find information about the commonly used Zigbee Cluster Library on this page.

The Open Wi-Fi version of SDM01 provides the following open APIs (refer to the Device API document), enabling users to implement local automation and connect to custom cloud platforms.

Zero-Configuration Discovery Mechanism (LAN Addressing)
- mDNS / DNS-SD: Supports automatic discovery of the energy meter by EV chargers and PV inverters on the Local Area Network (LAN) without the need for IP scanning.
BLE Near-Field Communication Mode (Offline/Maintenance)
- BLE GATT (Time-limited activation): Requires PIN code + PAKE algorithm authentication for local high-privilege configuration and network resets. Wakes up on demand and closes upon timeout.
- BLE Broadcast (Always-on 24/7): Unidirectional broadcast of AES-encrypted real-time power data, allowing nearby low-power devices to listen with zero latency and without requiring a connection.
LAN Standard Mode (Ultra-low Latency Device Communication) Plaintext or lightweight encryption for local networks.
- Modbus TCP: Used for local linkage with EV chargers and PV inverters.
- Local MQTT: Used for local integration with open-source smart home ecosystems.
- WebSocket (WS) / Raw UDP: Ultra-high frequency real-time power streaming subscription (enables DLB completion within 1-2 seconds).
- HTTP / CoAP: Suitable for low-frequency parameter configuration and status queries.
Cloud Device Access Layer (Device-to-Cloud / Southbound API)
- MQTTS (MQTT over TLS 1.2/1.3): Core main communication link.
- HTTPS (OTA dedicated): Exclusively used for downloading large Over-The-Air (OTA) firmware upgrade packages.