The KD type multi-user energy meter adopts advanced application specific integrated circuit design and fully automatic surface mount (SMT) production process to ensure long-term stable operation of the whole machine. It has advanced technical characteristics such as high precision, high overload, low power consumption, and high reliability.

Direct access type electric energy meter, accuracy: Level 1, in accordance with the standards GB/T17215.301-2007 "Special Requirements for Multi functional Electric Energy Meters" and JB/T10451-2004 "Special Requirements for Multi user Static AC Active Energy Meters", verification basis: JJG 596-2012 "Verification Regulations for Electronic AC Energy Meters". Product * * Large user quantity: 36 single-phase or 12 three-phase users. Within the range of large outgoing lines of the electricity meter * *, the number of three-phase users can be set arbitrarily, while the remaining outgoing lines are used by single-phase users.

External transformer type electric meter, accuracy: 0.5S level, in accordance with the standard GB/T17215.301-2007 "Special Requirements for Multifunctional Energy Meters", calibration basis: JJG 596-2012 "Verification Regulations for Electronic AC Energy Meters". Product * * Large user quantity: 8 three-phase households.

The electric meter has an RS485 communication interface, which can be used to connect the mobile phone electric meter and the upper computer to form a dedicated network or locally use the RS485 bus structure. It can communicate with the upper computer through telephone lines, fiber optics, GPRS wireless methods, and can also be applied to the locally connected RS485 network using an RF card electricity sales query device. After networking in different ways, using the upper computer and corresponding management software, data communication with the electricity meter or data transmission through RF cards can be achieved to retrieve and control electricity sales or user electricity consumption information.

1. Working principle and composition

The electricity meter obtains voltage sampling signals from voltage transformers and current sampling signals from current transformers. After passing through a dedicated energy metering chip, the voltage and current signals are obtained, processed by the CPU, and displayed on the LCD screen.

The CPU reads energy pulses from a dedicated energy metering chip, performs calculations, and stores them in memory. Managed by a computer information system, a certain amount of electricity and monitoring requirements are written through 485 communication, input into the microprocessor system in the table, and after CPU calculation, display and other functions are provided.

2. Specification and model

3. Introduction to functions and features:

1. Functional features:

◆ Prepaid function, users purchase electricity first and then use it, and power off if overdue.

◆ Overload protection function, when the user's load exceeds * * large load, the user will automatically power off for protection.

◆ Power off automatic recovery function. After the user loses power protection, within the specified number of power outages, if the user's maximum power drops to within the allowable range, the system will automatically restore power supply.

◆ Low battery alarm function, which can set the alarm battery level. When the user's electricity consumption is below the set value, it can provide a power-off prompt to the user. The user can swipe their card to restore power supply. (485 network networking mode can set automatic power restoration time)

◆ Allow overdraft power function, different overdraft power can be set according to user reputation, and power will be cut off if overdue fees exceed the set parameters.

◆ Set tiered power and tiered unit price function: Two sets of tiered parameters can be set, each set can be divided into multiple stages (* * 8 more), corresponding to the set unit price; The electricity meter has the function of saving electricity usage records, which can save the electricity usage history of the past 6 months (including the current month);

2. Technical features:

The electric meter adopts an original imported processor, which has low power consumption, high integration, fast operation speed, stability, and reliability

The volume of the watch box is smaller, and the internal wiring is neat and orderly.

The power supply adopts an iron sheet transformer, which reduces the electromagnetic interference of the power supply on weak current circuits.

Add relay detection function inside the electric meter, which can detect the status of the relay online through software. The software can judge the quality of the relay by itself.

The electric meter has a phase loss protection function. For three-phase users, if there is a phase loss caused by power supply phase loss or relay failure, it can automatically perform phase loss protection to ensure the * * operation of the user's three-phase equipment.

The incoming and outgoing lines of the electric meter use dedicated wiring terminals, which have stronger current carrying capacity and are more convenient for on-site construction;

The single-phase electricity meter can be used for 36 households or any combination of single-phase and three-phase electricity for 36 households or less. The operation of setting the number of households is simple, and the number of single-phase and three-phase users can be directly set through software, which can be changed at any time without dismantling the meter or returning to the factory, as long as sufficient outgoing lines are ensured.

The pulse and communication interfaces of the electric meter use dedicated wiring terminals to avoid the problem of missing or lost accessories, which is more in line with the needs of engineering installation.

The electric meter communication has lightning protection circuits and uses independent modules, greatly reducing the damage caused by lightning strikes to the electric meter.

The electric meter drive circuit adopts a dedicated chip, with a simple circuit, few fault points, strong anti-interference ability, and more reliable operation;

The current transformer in the electric meter adopts a dedicated transformer board, which is installed by welding and placed at the front end of the meter; Reliable connection, disconnected from copper bars and relay contacts, to prevent the possibility of contact heating and burning the transformer.

The electricity meter adopts the standard DL+T+645-2007 communication protocol, which is open and compatible, making cooperation with system integrators more convenient;

The electricity meter can achieve one card function with single-phase electricity meters and water meters of the same series;

IIMain technical parameters

1. Direct access electric energy meter

Rated voltage: AC~3x220/380V;

Accuracy level: Level 1;

Calibration currents of 5 (40) A, 15 (60) A, and 20 (80) A;

Pulse constant: 900imp/kWh; 20（80）A-400 imp/kWh；

Electricity division: 0.01 degrees;

Working temperature range: -25 ℃ to+55 ℃

2. External transformer type electric meter

Rated voltage: AC~3x220/380V;

Accuracy level: 0.5S level;

Calibration current of 1.5 (6) A;

Pulse constant: 5000imp/kWh;

Electricity division: 0.01 degrees;

Working temperature range: -25 ℃ to+55 ℃

3、 Electric meter appearance and installation dimensions

1. Appearance and installation dimensions of direct access control type electric meters

2. Transformer remote control electric meter appearance and installation dimensions

4、 Connection of electricity meter power line, outlet line, and control line

1. Direct access electricity meter

The power supply incoming line is a three-phase four wire system, with the live line serving as the common line for electricity meter users and allocated to the power supply outgoing line within the meter. The neutral line is only provided for the meter itself, and the user's neutral line needs to be provided to the user outside the meter through the neutral line busbar.

◎ Electricity meter power supply connection

The electricity meter is connected to the power supply using dedicated wiring terminals, and the live wire end is connected using a copper terminal block. The maximum cross-sectional area of the terminal block is 6 × 25 (150mm2), which is fixed with M8 screws. The neutral wire is made of multi-core copper wire, and the end is stripped 15mm and directly crimped. The cross-sectional area is not less than 2.5mm2, as shown in Figure 2

◎ Electricity meter user household wiring:

The electricity meter is connected to users who have only one live wire+neutral wire or a three-phase four wire system. The user output of the electricity meter is the phase wire (live wire), which is generally connected to the terminal block. The user's neutral wire is centrally connected to the neutral wire terminal block of the distribution box. When the electricity meter is set to a three-phase user, the three-phase user occupies the lower numbered output line. For example, when one three-phase user is set up, the user occupies 1/2/3 of the line, when two three-phase users are set up, the second three-phase user occupies 4/5/6 of the line, and the rest is occupied by single-phase users. Figure 3 shows a pure single-phase user connection, while Figure 4 shows a mixed single-phase and three-phase user connection.

Principle of three-phase user occupancy line:

Low numbered outgoing lines are taken from the three adjacent power sources of the starting line, which are the three phases of the input power supply;

Starting line number X, satisfies: (X-1)/3, remainder is 0, such as: 1, 4, 7, 10

2. Transformer type electric meter

The user output line of the transformer type electric meter is the rated current In=5A industrial transformer secondary output line, and the recommended wire cross-section is 2.5 mm2 multi-core copper wire. For three-phase users, three industrial transformers must be used, and the wire connections must be reliable to prevent secondary open circuits in the transformers.

◎ Remote control meter wiring for transformers (Figure 5)

The relay of a transformer controlled electric meter does not directly control the user's load line like a directly connected electric meter. Instead, it provides the user with an auxiliary switch (or a set of switches) that can be connected to other control circuits and use other high-power switches to achieve load control or alarm reporting. The capacity of the relay switch inside the electricity meter is AC250V/5A.

5、 RS485 communication

The electricity meter provides an RS485 communication interface and is connected to a network using dedicated communication twisted pair cables. The reading and control of electricity meter parameters are achieved through an upper computer.

When building an RS485 communication network, bus or star radiation methods are generally used. When connected by bus, it is recommended to use the method shown in Figure 6; When connecting using the method shown in Figure 7, the distance between the two T-shaped points should be greater than 1 meter, and the length of the branch wire should be less than 10cm. When using the star connection method, see Figure 8. When the communication distance is far or the communication quality is poor during testing, a 120 Ω load resistor should be connected in parallel at the far end (terminal) of the bus to prevent echo oscillation and reduce communication quality.

In general, when using dedicated twisted pair cables and communication speeds below 9600bps, reliable communication can be achieved over a distance of 1200 meters. When the communication speed decreases, the communication distance increases, depending on the site conditions

6、 Accessories