1. Introduction
The Zemismart SDM02T is a smart 2-phase energy monitor designed for real-time monitoring of electrical data. It consists of a compact monitoring module and two split-core current transformers (CTs). This device integrates with smart home ecosystems like Tuya and Home Assistant via a Zigbee hub, allowing users to track energy consumption, detect anomalies, and manage power usage efficiently. This manual provides essential information for safe installation, operation, and maintenance of your SDM02T energy meter.
Figure 1: Zemismart SDM02T 2-Phase Energy Monitor components.
2. Safety Information
2.1. Hazard of Electric Shock, Explosion or Arc Flash
- SDM02T sensors must ONLY be installed, operated, serviced, and maintained by qualified professionals.
- Apply appropriate personal protective equipment (PPE) and follow safe electrical work practices. Refer to NFPA 70E, CSA Z462, DL/T 320 or local equivalent standards.
- Turn off all power supply sources before installing and during maintenance of this equipment.
- Always use a properly rated voltage sensing device to confirm power is off.
- Do not use a SDM02T for voltage testing purposes. A dedicated Voltage Tester must be used instead.
- Failure to follow these instructions can result in death, serious injury, or equipment damage.
2.2. Fire Hazard
- SDM02T must be associated with an easily accessible upstream protection and circuit-breaker system.
- The ends of voltage take-offs cables must be adjusted to the according equipment and device. Such an adjustment can only be handled by qualified professionals.
- Failure to follow these instructions can result in death, serious injury, or equipment damage.
2.3. Risk of Damaging the Device
- Comply with the phase and the neutral position. Connecting the N pole of the voltage measurement connector to phase voltage is strictly forbidden.
- Ensure that the split-core current transformers are not in direct contact with non-insulated conductors.
- Disconnect the voltage take-offs of SDM02T before performing the dielectric withstand test or insulation measurements.
- Limit the insulation measurements up to 500 VDC.
- SDM02T can only be installed upstream if associated with a contactor, frequency converter or motor starters.
- The product could be damaged if the blue cable for N connection is mistakenly connected to phase conductors.
3. Product Description
The Zemismart SDM02T is a smart energy monitor designed for accurate real-time monitoring of electrical parameters. It features Class 1 energy accuracy, easy installation, APP control, alarm messages, and bi-directional monitoring capabilities.
Figure 2: Key features of the SDM02T energy monitor.
3.1. Parts Description
Figure 3: Labeled components of the SDM02T monitor and split-core CTs.
| No. | Component | Description |
|---|---|---|
| 1 | Pluggable terminal for the wire of voltage | Connects the voltage input wires. |
| 2 | Pluggable terminal for the wire of current transformer | Connects the CT wires to the monitor. |
| 3 | Reset button | Used to reset the device or enter pairing mode. |
| 4 | Status LED | Indicates device status (pairing, connection, alarms). |
| 5 | Product QR code | For device identification and app pairing. |
| 6 | Product model | SDM02T-TZ. |
| 7 | Calibration ID | Unique identifier for calibration. |
| 8 | Split-core CT locking clasp | Secures the CT around the conductor. |
| 9 | Positive energy flow direction | Indicates the correct orientation for current flow measurement. |
3.2. Technical Specifications
Figure 4: SDM02T Product Parameters.
| Parameter | Value |
|---|---|
| Product Model | SDM02T-TZ |
| Rated Operating Voltage Un | 110~240 VAC L-N, 50/60 Hz |
| Max Current Imax | 120 A |
| Over-voltage Category | III |
| Rated Isolating Voltage Ui | 250 V |
| Rated Impulse Withstand Voltage Uimp | 4 kV |
| Pollution Degree | 3 |
| Protection Degree | IP20 |
| Energy measurement accuracy class (IEC61557-12) | Class 1 |
| Rated Operating Temperature | -25~70 °C |
| Maximum Power Consumption | ≤ 2 VA |
4. Setup and Installation
4.1. Requirements
- A Tuya Zigbee Hub or Zigbee2MQTT dongle is required for smart control and monitoring. (Not included in the product package).
- Latest version of the Smart Life app installed on your mobile device.
- Qualified professional for installation.
Figure 5: Zigbee Hub Requirement.
Figure 6: Tuya Zigbee Hub or Zigbee2MQTT dongle is required for data monitoring.
4.2. Wiring Diagram
The SDM02T is suitable for use in UL single-phase (split-phase) three-wire systems and UL/IEC single-phase systems up to two branch circuits. Ensure all power supply sources are turned off before installation and during maintenance.
Figure 7: Wiring Diagrams for various single-phase systems.
Figure 8: Application Illustration for SDM02T wiring.
Figure 9: Detailed wiring for a 2-phase system.
Figure 10: Detailed wiring connections.
Installation Steps:
- Insert the voltage wire into the pluggable terminal.
- Insert the wire of the current transformer into the pluggable terminal.
- Install the Current Transformer around the live wire. Ensure the positive energy flow direction arrow on the CT points towards the load.
Figure 11: Bi-directional Measurement illustration.
4.3. Quick Setup (App Pairing)
Before activating the SDM02T sensor, ensure you have the latest version of the Smart Life app. If your device is a Zigbee version, install a Tuya Smart Zigbee gateway beforehand.
- Connect your mobile phone to the wireless network.
- Open the Smart Life App.
- Tap "Home" and then tap "+" in the top right corner to enter the "Add Device" page.
- The app will scan for smart devices. Once the SDM02T sensor appears, follow the in-app prompts to complete the pairing process.
Figure 12: App pairing process illustration.
5. Operating Instructions
5.1. Tuya APP Control
Key electrical data such as voltage, current, and power can be monitored in real-time via the Tuya APP. The app provides a comprehensive overview of your energy consumption.
Figure 13: Tuya APP Control interface.
Figure 14: Tuya APP data points explained.
5.2. Home Assistant Real-time Monitoring
When paired with a Zigbee2MQTT dongle, all data becomes accessible for monitoring through Home Assistant, offering detailed insights into your electrical system.
Figure 15: Home Assistant Monitoring interface.
Figure 16: Alternative Home Assistant Monitoring view.
5.3. More Data & Electricity Consumption Statistics
On the device settings page, click "More Data" to set "Device Locating", "Interval for Data Reporting", and view L1 and L2 electricity data. You can also view daily, monthly, and yearly electricity consumption charts.
Figure 17: 'More Data' settings.
Figure 18: Accessing detailed electricity data.
Figure 19: Electricity Consumption Statistics.
5.4. Alarm Messages
Alarms can be configured in the APP settings to receive notifications when electrical data is abnormal. This helps in preventing short circuits and protecting household electricity safety.
Figure 20: Alarm settings in the app.
5.5. Energy Management
On the device settings page, click "Energy management" to clear existing energy data.
Figure 21: Energy Management feature.
6. Indicator Light Description
The Status LED on the SDM02T monitor provides visual feedback on the device's operational status. Refer to the table below for detailed explanations.
| Status LED | Description |
|---|---|
| ON, normal using, connected to cloud | The device is operating normally and connected to the cloud. |
| Flashing at 2Hz, in pairing mode | The device is ready for pairing. Press the reset button until the LED flashes quickly to enter this mode. |
| Flashing at 0.5Hz, paired, searching for cloud | The product is not currently connected to the wireless network and is searching for it. |
| Flashing at 1Hz, wireless communication failed | Failed to communicate with the cloud. Check if the supply voltage is too low. |
| Flashing at 0.25Hz, self-checking failed | Self-check failed. Try restarting the device by disconnecting power, switching it on, and then repairing. |
| Flashing at 1Hz, alarm notification active | An alarm condition is active. Check device wiring and alarm information in the app. |
7. Troubleshooting
- Device not connecting to app: Ensure the Zigbee hub is properly set up and connected. Check the device's Status LED for pairing mode (flashing at 2Hz) or communication failure (flashing at 1Hz). Verify your mobile phone is connected to the same wireless network as the hub.
- Inaccurate readings: Confirm that the split-core CTs are installed correctly with the positive energy flow direction arrow pointing towards the load. Ensure the voltage measurement matches the current measurement (L1 with CT1, L2 with CT2).
- "Device Locating" function: This setting, found under "More Data" in the app, is typically used to help identify the physical location of the device within a larger smart home setup, or to assign it to a specific room for better organization and monitoring.
- No data in Tuya app for bi-directional measurement: Note that the bi-directional measurement feature for specific values and charts is only supported on Home Assistant through Zigbee2mqtt, not directly on the Tuya app.
- Alarms not received: Check your app's notification settings and ensure alarms are enabled for the desired conditions. Verify network connectivity.
8. User Tips
- For optimal energy monitoring, regularly check the "Electricity consumption statistics" in the app to identify trends and potential areas for energy saving.
- Utilize the "Alarm set" feature to configure alerts for abnormal electrical usage, such as over-current or over-voltage, to proactively protect your electrical system.
- If using Home Assistant, leverage its advanced automation capabilities to create custom routines based on the energy data provided by the SDM02T.
9. Warranty and Support
For detailed warranty information and technical support, please refer to the official Zemismart website or contact their customer service. A comprehensive user manual in PDF format is available for download, which includes additional details and diagrams. You can find the PDF manual here.
Video: Product overview and installation demonstration (Spanish).
