njoy DDSU666 Single Phase Energy Meter User Manual

njoy DDSU666 Single Phase Energy Meter User Manual

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Please read this manual before using the product.

A Smart Meter is a bidirectional device that records the load curve and controls the various energy flows, giving highly accurate measurements and rapid communication through the chosen communication network.

nJoy inverters models that are compatible with this product:

2K/3K/4K/5K/6K/ 7K/8K/10K

5k/6K

NOTE!
If any of the above package content is missing or is damaged please contact the shop where you have bought the product from.

Brief Introduction

1.1. Main application & applicable range

Type DDSU666 single phase electronic energy meter (din-rail) (hereinafter referred to as the “instrument”) is designed based on power monitoring and energy metering demands for electric power system, communication industry, construction industry, etc. as a new generation of intelligent instrument combining measurement and communication function, mainly applied into the measurement and display for the electric parameters in the electric circuit including voltage, current, power, frequency, power factor, active energy, etc. The network can be realized through RS485 communication interface and external device. Adopting the standard DIN35mm din rail mounting and modular design, it is characterized with small volume, easy installation and easy networking, widely applied into the internal energy monitoring and assessment for industrial and mining enterprises, hotels, schools, large public buildings.

1.2. Product Features

1. Metering the positive and negative active power.
2. Adopting wide LCD, it has clear vision.
3. RS485 communication function with communication protocol complied with Modbus-RTU.
4. Adopting DIN35mm standard din rail mounting, structural modular design, it is characterized with small volume, easy installation and easy networking.

1.3 Model composition and meanings

Figure 1 Model No. & meanings

1.4 Applicable environmental condition.

Regulated working temperature range: -25°~C+60°C
Limited working temperature range: -35°C~+70°C
Relative humidity(Annually average):75%
Atmospheric pressure:86kPa~106kPa

Working Principle

The working principle block diagram of the instrument is shown in figure 2:

Figure 2 Work principle block diagram

Main Technical Performance & Parameters

3.1 Model specification

Table 1 Model specification

NOTE!

Please take the physical sign as standard.

3.2 Percentage error

Table 2 Percentage error of single phase energy meter not exceeding the below corresponding limited value

NOTE!

In: secondary rated current of the current transformer; Ib: calibrated current of the meter;
L:inductive; C: capacitive;

3.3 Start

Table 3 Under the referenced voltage and table 4, the energy meter can be started and continuously measure the energy

3.4 Defluction

The electric energy meter should have good anti-defluction logic. When the voltage loop with 1.15 times of referenced voltage and the current loop is disconnected, the energy will not produce more than one pulse.

3.5 Defluction

Table 4 Electrical parameters

3.6 Other technical parameters

Table 5 Other technical parameters

3.7 Adoption for key components

Table 6 Adoption for key components

NOTE!

The actual plate number is determined according to the actual sample table.

Main functions

4.1 Metering function

1. Accurately metering the positive and negative active power;
2. The storage data of the electric energy meter will not lost after powering off.

4.2 Displayed functions

When the energy meter is in normal working condition (on load state), the positive pulse indicator should be flashed. If long time for no flashing or light for the indicator, please check whether the wiring mode of the energy meter is right or not.

The display time of the measurement data is five seconds and information sample for every page of the measured information of measurement data (if not consistent with the instrument panel, please take the object as standard.)
Light time of the background: 1 min.

Keyboard operation: After pressing the button for a long time, the display interface enters the switching interface of setting 645 protocol and Modbus protocol. Shortly press can switch the protocol, not the address page (only the ModBus protocol can be switched to the address page), the address of ModBus can be set by the button, the button can set the address range 1-99

Figure 3 Long press button

4.3 Communication function

The instrument adopts RS485 communication mode with baud rate to be set as 1200, 2400bps, 4800bps and 9600bps.For a same communication circuit, it can at most be connected with thirty-two instruments at the same time, with each instrument to be set as their communication address. For the communication connection, it should use shielded twisted pair with copper
mesh with wire diameter not below 0.5mm2 . On wiring arrangement, the communication line shall be away from strong cable or other strong electric field with the maximum transmission distance to be 1200m. For the typical networking connection mode, please see the below figure, users can select other suitable connection mode based on detailed conditions.

Figure 4 Schematic diagram of communication connection

When the instrument is set to be ModBus-RTU transmission mode, ModBus-RTU communication protocol adopts host-slave response in one communication line. Firstly, the host computer’s signal will seek for a terminal device (slave) with only one address, then the terminal device will produce response signal and transmit to the host computer in opposite direction, that is, half duplex working mode. This protocal only allows communication between the host (PC, PLC, etc.) and the terminal device, rather than data exchanges between the independent terminal devices. Thus, each terminal device will not occupy the communication circuits in their initialization, and only be limited to response the query signal to the host computer. The instrument can provide ModBus-RTU communication protocol (see appendix A), for the parameter information to be read or modified by the communication, please see the below table.

ChangeProtocol such as protocol switching, data for 2 for Modbus RTU protocol -, data to 1 for DL/T 645-2007;
The CLr. E power reset write 1 removal of total power; BAud rate: 1:2400bps; 2:4800bps; 3:9600bps;

4.4 Outline &Mounting Dimension

Outline dimension: 36mm×98mm×65mm
Din rail mounting dimension: 35mm, with configuration to be shown as figure 4

Figure 5 Configuration

Installation & Operation Instruction

5.1 Inspection

1. Before installation, firstly check whether the model No. and specification of the product on the package is the same as the object. If not, please contact the supplier.
2. Check whether the product shell in the carton is damaged, if is, please contact the supplier.

5.2 Installation

Directly clip the instrument on the rail and install it on the distribution box.

1. When installing, firstly clip one terminal of the slot and then clip to the rail with power.
2. When disassembling, press the movable card with a screwdriver and take out the instrument.

5.3 Wiring mode

6.3.1 Instruction of wiring terminal

Before powering, you must check whether the wiring mode of the instrument is correct, and the wiring diagram is shown as below:

Figure 6 Direct connection

Figure 7 Via transformer

Diagnosis, analysis and elimination of common faults

If the above method cannot eliminate the fault, please contact with the aftersale service of digital meter from Zhejiang CHINT Instrument Co., Ltd.

Transportation & Storage

The package of the instrument shall adopt materials complied with environmental protection, under package condition, the instrument and accessories shall be stored in the dry and ventilated places, to avoid humidity and corrosive gas erosion, with the limited environmental temperature for storage to be -40°C!+70°C and relative humidity not exceeding 75%. The package of the instrument shall comply with the provisions of GB/T 13384- 2008 of General specifications for packings of mechanical and electrical products with the environmental temperature requirement and transportation for the normal storage complied with the provisions of GB/T 25480-2010 of Basic environmental conditions and testing methods for instruments transportation and storage Complete set of package for single product, including:

1. One set of instrument
2. One operation manual
3. One bag of desiccant
4. Certificate

Maintenance & Service

Appendix A: MODBUS-RTU Communication Protocol
A.1 Communication format
Information transmission adopts asynchronous mode, taking byte as the unit.
The communication date transmitted between the host and slave computer is the format of 10-digit characters, including one start bit(0), 8 data bits without check bit, two stop bits(1)(other format can be customized). Format of information frame:

Table A.1

A.2 Communication information transmitting procedure
When communication command is transmitted from the host computer to the slave computer, the slave computer which matches the address code sent by the host computer receives the communication command. If CRC checks without any fault, then the corresponding operation will be carried out, after that the implement result (date) is returned to the host computer. The returned information contains address code, function code, implement date and CRC check code.

A.2.1 Address code
Address code is the first byte of each communication frame, with the range from 1 to 247. Each slave must have an exclusive address code in the bus, only the slave computer which matches the address code sent by the host computer can respond returned information. When the slave computer returns the information, the returned data will begin with their respective address codes. The address code sent from the host computer indicates the slave address, the returned address code from the slave computer indicates the slave address, while the corresponding address code indicates where the information comes from.

A.2.2 Function code
It’s the second byte of each communication frame. It’s sent by the host and tells the slave computer what actions should be carried out through function code. The slave will respond, and the functional code is the same as that sent by the host computer, which indicates that the slave computer has responded the host and complemented the relative operation. The instrument supports the following two function codes:

Table A.2

A.2.3 Data area
The data field will be different based on different function codes. These data can be numerical values, reference addresses and so on. For different slave computers, both the address and data information are different, and the communication information table should be provided. The host utilizes communicate command (function code 03H and 10H) to read and modify the data registers of the slave freely. But the data length which is read or write at one time should not be out of the effective range of the data register’s address.

A.3 Brief introduction of function code
A.3.1 Function code 03H: Read register
For example: The slave address which the host intends to read is 01H, the start register address is two register data of 0CH, sent by the host:

Table A.3

If the data of the slave register 0CH, 0DH is 0000H, 1388H, the slave will return:

Table A.4

A.3.2 Function code 10H: Write multi-port register
For example: The host intends to save data of 0002H, 1388H, 000AH into the slave address of 01H, the start register address is the three registers of 00H, sent by the host:

Table A.5

Returned by the slave

Table A.6

A.4 16-digit CRC check code
The host or slave computer can be judged by the check code to see if the received information is correct or not. The interruption by electronic noises or other factors may cause errors during information transmission. 16-digit CRC check code is calculated by the host, located at the end of the transmit information frame. The slave recalculates the received information of CRC and compares if the calculated CRC goes in line with the received CRC, if not, there is an error. Only 8 data bits are used during CRC calculation, both the start bits and the stop bits are not involved in the calculation.

The calculation method of CRC check code is stated as follows:

1. Pre-arrange one 16-digit register as a hexadecimal FFFF ( i.e. fully 1), the register is called CRC register;

2. Make the first 8-digit binary data ( the first byte of the communication information frame) with the lower 8 digits of the 16-digit CRC register by XOR calculation, the result is placed in CRC register;

3. Shift the content of CRC register rightward by one digit (towards the lower digit) and fill in the highest digit with 0, check the shift-out digit after rightward shifting;

4. If the shift-out digit is 0: repeat step 3) (shift rightward one digit again);
   If the shift-out digit is 1: make CRC register with multinomial A001 by XOR calculation

5. Repeat step 3) and 4) until shift rightward for 8 times, then all the 8 digits are processed;

6. Repeat step 2) and 5), process the next byte of the communication information frame;

7. After calculating all the bytes of the communication information frame (exclude CRC check code) according to the above steps, the content of the CRC register to be get is: 16-digit CRC check code

A.5 Error handling
When the meter detects other errors except the error of CRC check code, the information will be returned to the host, the highest digit of the function code is 1, i.e. the function code returned to the host from the slave is adding 128 base on the function code sent from the host. The error returned from the slave is as follows:

Table A.7

Error code is as follows:

Table A.8

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