DDSY256 Single Phase Electronic Type Prepaid Watt-

Specifications and main technical parameters 1. In accordance with the International standard IEC61036 2. Rated voltage: 220V; 3. Calibrated current: 5(20)A; 10(40)A; 15(60)A; 20(80)A; 30(100)A; 4. Rated frequency: 50Hz/60Hz; 5. Relative humidity ≤ 85%; 6. Accuracy class: Class 1.0;2.0 7. Power consumption of whole machine: Less than 2W; 8. Starting current: 0.4%Ib (class 1.0), 0.5% Ib (class 2.0) basic current; 9. Function of anti-creep: Anti-creep logical design; 10.With RS485 communication port; 10. Data save: Data can be saved equal to or more than 11 years after power off; 12. Service life: More than 10 years 13. Weight: About0.8Kg; Main functions and characteristics 1. Standard IC card hardware-based cryptographic for prepayment, the power supply department receives the electric charge in advance by means of vending the power utilization card (IC card), and users should buy first for power utilization. 2. It integrates full-digital metering with using electricity power consuming display, prepayment control, reading card and intelligent anti-power stolen, ect., has high reliability. 3. Function of overload protection. When the load exceeds the preset maximum current for a continuous period, it would cut off the power supply circuit automatically, nixie tube would display warning symbol flickeringly, and the watt-hour meter would switch off automatically after a certain period of time delay. 4. The power utilization IC card is treated with software and hardware-based cryptographic, guaranteeing safety, correctness and reliability of data. Through special design, the IC card records the residual and cumulated electric quantity of meter as well as information about electricity-stolen if there is while user inserts the card. 5. Perfect card interface protection circuit, preventing hostile attack behaviors effectively. 6. Display of residual electric quantity, it displays in 6-digit (5 integral numbers, 1 decimal number). 7. When the residual electric quantity reaches the prep warning value, nixietube would display the residual electric quantity, reminding users to input new electricity purchasing quantity. 8. When the residual electric quantity in watt-hour meter remains zero, the watt-hour meter would trip automatically, and cut off the power supply, at this moment, users must bring the card and go to power vending department to purchase electricity (power supply department could set a certain quantity for overdrawing, insert the card, users could use a certain quantity of electricity), only when inserting the card with effective electric quantity into the meter that it could supply power normally. 9. The power would be cut off automatically when the owed electric quantity reaches a certain degree, input new electricity purchasing quantity (after deducting the over-consumed electricity), the power supply would be recovered automatically. 10. Application of magnetic latching relay not only improves reliability of power interruption operation, reduces power consumption after power off, but also conquers the shortcoming of relay of contacts adhesion when working for long time at heavy current. 11. When coming across power failure, it would store the data automatically, and resume data at power recovery. 12. Computer, special IC card read-write device and charging management software form the electricity vending management system. 13. Carry out comparative analysis to the recorded information, the management system is able to list out users suspected of electricity stealing action for concentrated investigation, reducing the working capacity of anti-electricity stolen and electricity stolen investigation. 14. If the watt-hour meter is reversed connected, it still is able to meter correctly.