1. Introduction
This manual provides detailed instructions for the installation, operation, and maintenance of your EARU Three Phase Four Wires Electronic Active Energy Meter. These meters are designed for accurate measurement of active energy (kWh) in three-phase four-wire AC circuits. They are suitable for various applications requiring precise power consumption monitoring.
2. Safety Information
- Installation and maintenance should only be performed by qualified electricians.
- Ensure the power supply is completely disconnected before any installation or wiring work.
- Verify all connections are secure and correct according to the wiring diagrams to prevent damage to the meter or electrical system.
- Do not operate the meter in environments exceeding its specified operating temperature or humidity ranges.
- The meter's circuit intervals can withstand impulse voltage with a waveform of 1.2/50uS, peak value 6KV, without electric arc or damage.
- All circuit insulating earthing can withstand AC voltage 2KV with actual sine wave 50Hz for 1 minute.
3. Package Contents
Upon opening the package, please verify that you have received the following items:
- 1 x EARU Three Phase Four Wires Electronic Active Energy Meter (Specific model as ordered)
- 1 x Instruction Manual (This document)
4. Specifications
| Attribute | Value |
|---|---|
| Model Number | EA770/EA771/EA772/EA777 |
| Brand Name | EARU |
| DIY Supplies | Electrical |
| Phase | Three Phase |
| Display Type | Analog and Digital (LCD/LED) |
| Accuracy Class | 1.0 |
| Rated Voltage | 220V (Reference: 3 x 127/220(V) or 3 x 220/380(V)) |
| Power Supply | AC |
| Operating Temperature | -30℃ to 65℃ |
| Dimensions | 126mm * 90mm * 74mm |
| Battery Included | No |
| High-concerned chemical | None |
| Origin | Mainland China |
| Certification | CE |
| Working voltage limit | 70 ~ 130% Ub |
| Power consumption | ≤2W and 10VA/ phase |
| Rated Current | 3 X 5(100)A |
| Frequency | 50HZ/60HZ |
| Constant Pulse | 400imp/kWh |
| Installation | 35mm DIN rail |
| Degree of Protection | IP20 (for EA771) |
| Starting Current | 0.004Ib (for EA771) |
| Storage Temperature | -25 ~ 70℃ (for EA771) |
| Operating Voltage | 0.9-1.1 Rated Voltage (for EA771) |
| Utmost Voltage | 0.7-1.2 Rated Voltage (for EA771) |
Note: In the column of Rated Current, the value before the bracket is demarcated current value Ib, and the value in the bracket is the maximum current Imax.
Figure 1: EA771 Dimensions and Detailed Specifications
5. Product Overview and Model Differences
The EARU Three Phase Four Wires Electronic Active Energy Meter series includes several models, each offering specific features. All models are designed for DIN rail installation and provide accurate energy measurement.
Figure 2: Overview of different EARU Energy Meter models (EA771, EA770, EA770-C, EA777, EA772)
5.1 Model Feature Comparison
| Feature | EA771 | EA770 | EA770-C | EA777 | EA772 |
|---|---|---|---|---|---|
| Total Power | ✔ | ✔ | ✔ | ✔ | ✔ |
| Active Power | ✔ | ✔ | |||
| Reactive Power | ✔ | ✔ | |||
| Frequency Display | ✔ | ✔ | |||
| Bi-Directional Measuring | ✔ | ✔ | |||
| Power Factor | ✔ | ✔ | |||
| RS485 Communications | ✔ | ✔ | |||
| Voltage/Current Display | ✔ | ✔ | |||
| Baud Rate Display | ✔ | ✔ | |||
| Reset Power Consumption | ✔ | ✔ |
Figure 3: Feature comparison across different EARU Energy Meter models.
5.2 Display Types
Some models feature different display types:
- LCD Display: Provides a clear digital readout of energy consumption (e.g., EA771, EA770, EA772, EA777).
- Counter Display: Features a mechanical counter for energy readings (e.g., EA770-C).
Figure 4: Examples of LCD (EA770) and Counter (EA770-C) displays.
5.3 Energy Measurement
Models like EA777 and EA772 offer advanced measurement capabilities:
- Positive Active Electric Energy: Standard energy consumption measurement.
- Reverse Active Electric Energy: Measures energy flowing back into the grid, useful for systems with generation (e.g., solar).
Figure 5: EA777 displaying both positive and reverse active electric energy.
6. Setup and Installation
The energy meter is designed for 35mm DIN rail installation. Follow these steps carefully:
6.1 Physical Installation
- Ensure the main power supply is OFF before beginning installation.
- Mount the meter onto a standard 35mm DIN rail in your electrical panel. The meter features clips on the back for secure attachment.
- Once mounted, ensure the meter is stable and does not wobble.
Video 1: Product demonstration showing physical handling and basic wiring overview.
6.2 Wiring Diagrams
Proper wiring is crucial for accurate measurement and safe operation. Refer to the specific wiring diagram for your meter model.
6.2.1 EA770 Wiring
Figure 6: EA770 Wiring Diagram. Connect L1, L2, L3, N for both input and output as shown.
6.2.2 EA770-C Wiring
Figure 7: EA770-C Wiring Diagram. Connect L1, L2, L3, N for both input and output as shown.
6.2.3 EA771 Wiring
The EA771 model supports two wiring configurations: Up IN Down Out or Up Out Down In.
Figure 8: EA771 Wiring Options: Up IN Down Out (left) and Up Out Down In (right). Connect A, B, C, N lines accordingly.
Figure 9: EA771 detailed view showing wiring terminals, LCD screen, and power/pulse indicators.
6.2.4 EA772 Wiring
The EA772 model also supports bi-directional wiring for energy flow.
Figure 10: EA772 Wiring Options. Note the P+ and P- terminals for pulse output and 485A/485B for communication.
Figure 11: EA772 detailed view showing wiring terminals, display, and indicators.
6.2.5 EA777 Wiring
Figure 12: EA777 Wiring Diagram with P1-/P1+ for pulse output and 485A/485B for RS485 communication.
Important: Always double-check all wiring connections before restoring power. Incorrect wiring can lead to equipment damage or electrical hazards.
7. Operating Instructions
Once installed and powered on, the meter will begin measuring energy consumption. The display will show the accumulated kWh.
7.1 Reading the Display
- LCD/LED Display: The digital display shows the total active energy in kWh. Some models may cycle through other parameters like voltage, current, frequency, and power factor.
- Counter Display (e.g., EA770-C): The mechanical counter directly shows the accumulated kWh.
7.2 Indicators
- L1, L2, L3 Indicators: These LEDs illuminate to indicate the presence of voltage on each phase.
- Impulse Indicator: This LED flashes proportionally to the energy being consumed. A faster flash rate indicates higher power consumption. (Constant Pulse: 400imp/kWh).
7.3 Advanced Features (EA772, EA777)
For models like EA772 and EA777, additional features are available:
- Parameter Cycling: Use the 'SET' or 'PRESS' button (if present) to cycle through various display parameters such as Active Power, Reactive Power, Frequency, Power Factor, Voltage, Current, and Baud Rate.
- Reset Power Consumption: The EA777 model includes a function to reset power consumption readings. Refer to the meter's specific buttons ('SET', 'PRESS') for this operation.
8. Maintenance
The EARU energy meters are designed for long-term, maintenance-free operation under normal conditions.
- Cleaning: Keep the meter clean and free from dust. Use a soft, dry cloth for cleaning. Do not use abrasive cleaners or solvents.
- Environmental Conditions: Ensure the operating environment remains within the specified temperature and humidity ranges to prevent damage and ensure accurate readings.
- Inspection: Periodically inspect the wiring terminals for any signs of loosening or corrosion. Tighten connections if necessary, ensuring power is off.
9. Troubleshooting
If you encounter issues with your energy meter, refer to the following common problems and solutions:
- No Display/No Power:
- Check if the main power supply is on.
- Verify all wiring connections (L1, L2, L3, N) are secure and correctly terminated.
- Ensure the rated voltage matches your power supply.
- Incorrect Readings or No Impulse Flashing:
- Confirm that the current and voltage connections are correct and in phase.
- Ensure the load is connected properly.
- Check for any loose wiring that might affect measurement accuracy.
- Communication Issues (for models with RS485):
- Verify the RS485 A and B terminals are correctly connected to your communication device.
- Check the baud rate settings on both the meter (if adjustable) and your communication device.
User Tips
- 100A Support: The meter is rated for 3 X 5(100)A, meaning it can support up to 100A. Ensure your wiring and circuit breakers are appropriately sized for 100A if you intend to draw that much current. Always consult with a qualified electrician for high current installations.
10. Warranty and Support
EARU products are manufactured to high-quality standards. For warranty information, technical support, or service inquiries, please contact your retailer or the official EARU support channels. Keep your purchase receipt as proof of purchase.
