1、 Overview

The DDSY1791 electronic single-phase prepaid energy meter adopts a dedicated integrated circuit design and is manufactured using fully automatic surface mount (SMT) production technology. The circuit design and component selection of the electric energy meter are based on a large environmental tolerance, which can ensure long-term stable operation of the whole machine, high precision, high overload, low power consumption, and high reliability performance. Adopting advanced intelligent IC card technology that meets international standards to achieve prepaid payment, with built-in magnetic holding relay. By controlling the relay to control the on and off of the load, the function of urging users to buy electricity before using it can be achieved.

Main features: Application of computer management, purchasing electricity first and then using it; The maximum operating power can be limited within the rated current range (limited by the power supply department); One meter, one card, dedicated card, no power loss after card loss, can be used after card replacement; Electric cards can transmit data bidirectionally and automatically power off to alert users when purchasing electricity; When the battery level is zero, the power will automatically trip and cut off; And it has certain anti-theft software design, etc.

The product meets all technical requirements of GB/T17215.321-2008 "Level 1 and Level 2 Static AC Active Energy Meters" and GB/T 18460.3-2001 "IC Card Prepaid Electricity Sales System Part 3: Prepaid Energy Meters".

2、 Working principle

1Working principle diagram

The electric energy meter obtains voltage sampling signals from the voltage divider, current sampling signals from the current divider, voltage current product signals from the multiplier, and then generates a counting pulse proportional to the product of voltage and current through frequency conversion. Through frequency division, it drives the stepper motor to measure electricity.

2Data processing

The electric energy metering pulse is sent to the CPU through a photoelectric coupler for processing, and after calculation, it is stored in the memory. The information system is managed by a computer, and through an IC card reader/writer, a certain amount of electricity and monitoring requirements are written into the IC card input table of the microprocessor system. After being processed by the CPU, it provides display and alarm status signals.

3、 Specifications, models, and technical parameters:

1. Specification and model

2. Main technical parameters:

a、 Basic error:

b、 Electrical parameters (reference conditions):

Starting current: 0.4% Ib

Power consumption: Voltage line<1.0W, 3.0VA;

Current line<1.0VA

Stealth: equipped with logic anti creep circuit

Voltage range: 220V ± 10%

Working temperature range:- 25℃~ +55℃

Power failure data storage time>20 years

4、 Installation and use

1. The electricity meter has been inspected and qualified before leaving the factory, and sealed with a lead seal before installation and use. If there is no lead seal or it has been stored for too long, relevant departments should be asked to re verify and seal it before installation and use.

2. The electric meter should be installed in a dry and ventilated place, and the bottom plate for installing the electric meter should be fixed on a sturdy, fire-resistant, and vibration resistant wall. The height of the electric meter is about 1.8 meters.

3. Install and wire according to Figure 1 and Figure 2, tighten the wiring screws, and secure the connecting plate inside the terminal box.

4. The reading of an electric meter connected through a transformer must be multiplied by the transformation ratio to obtain the actual amount of electrical energy.

5. One table, one card: The IC card held by the user cannot be exchanged. In case of loss, a replacement card should be purchased from the power supply department (sales office).

6. Preparation for purchasing electricity: Before purchasing electricity, the user must insert the IC card into the card slot once to facilitate sending the data in the meter back to the computer database.

7. Electricity purchase method: When selling electricity, insert the IC card into the IC card reader and operate the computer to encrypt the user ID, pre purchased power, alarm power, capacity limiting method, and capacity limiting power into the IC card.

8. Electricity card usage: Insert the power purchase card into the card slot. If it is a valid power purchase card, the meter will automatically read the data into the meter. The LCD (LED) display screen will show the following in sequence: purchased electricity quantity (P0==XXXX), total purchased electricity quantity (P=XX XXXX), purchased electricity times (PC=XXXX), alarm electricity quantity (P1=XXXX), credit limit (P2=XXXX), and limited capacity power (F0X=XX: XX). Please store the unplugged card properly.

9. Operation display: During the operation of the electricity meter, it alternately displays the remaining electricity and total electricity consumption in the meter.

10. Overcapacity alarm: During the operation of the electricity meter, if the "alarm indicator light" flashes rapidly, it warns the user that the electricity has been exceeded. If the meter is set to the over capacity power-off limit mode, then the over capacity electricity will be used30In seconds, the brake will be pulled3Minutes and countdown display(180second)Time to restore power supply; If the user inserts the card and responds, the power supply can be immediately restored.

11. Accumulation limit: If the purchased electricity+remaining electricity>accumulation limit (10000kWh), the purchased electricity will not be read in, and the display will show a "remaining limit" prompt, indicating that the stored electricity in the card is still valid.

12. Warning reminder: When the remaining battery level in the meter is less than twice the "alarm battery level", the "alarm indicator light" will flash (with an interval of 1 second) to remind the user to purchase electricity. At this time, if the user responds by inserting a card, the "alarm indicator light" will flash at an interval of 2 seconds to avoid power outage warnings.

13. Power outage warning: If the user does not insert the card to respond to the warning reminder and sets an overload alarm, when the remaining power is the user's agreed alarm power (or 10% of the purchased power), the meter will pull off the power outage warning and display the "pull off" prompt. At this time, inserting the IC card into the card slot once will restore power supply. If the IC card of this meter cannot be found after pulling the switch, you can borrow a neighbor's IC card to insert it and restore power supply.

14. Power purchase reminder: When the remaining power in the meter is less than the "alarm power", the "alarm indicator light" will remain on as a constant reminder.

15. Fault declaration: When the remaining power is displayed as zero or negative, a "trip" prompt will be displayed. If the meter continues to operate, the user should immediately purchase electricity and proactively report the situation to the power supply department.