DTSDU866 7P three-phase multi circuit monitoring instrument

Product Introduction

1. Reference standards

Reference national standards:

• DL/T 614-1997 Multi functional Energy Meter

• GB/ T 17883 - 1999 0 . 2 S-level and 0 5 S-level Static AC Active Energy Meter GB/T 17882-1999 Level 2 and Level 3 Static AC Reactive Energy Meter

• GB/T 13850-1998 Electrical measurement transmitters for converting AC electrical quantities into analog or digital signals, referencing international standards

• IEC 62053-22:2003 Electricity measuring equipment (AC) - Special requirements - Part 22: Static energy meters (0 2 S-level and 0 5 S-class) IEC 62053-23:2003 Electricity measuring equipment (AC) - Special requirements - Part 23: Static reactive power meters (0 2 S-level and 0 5 S-level) IEC 61010-1: 2001 Safety requirements for electrical equipment for measurement, control and laboratory use - Part 1: General requirements IEC 61000-2-11 Electromagnetic compatibility (EMC) - Part 2-11

• IEC 60068-2-30 Environmental Testing - Part 2-30

2. Product Overview

• The three-phase multi-channel detection module is specifically designed and manufactured for the power monitoring needs of power supply and distribution systems It can measure all commonly used power parameters with high accuracy, including three-phase voltage, three-phase current, active power, reactive power, frequency, power factor, etc. of each circuit. At the same time, it also has functions such as energy accumulation, maximum support for 4-channel switch input, and large dot matrix LCD display, with a good human-machine interface.

• The three-phase multi-channel detection module has extremely high cost-effectiveness and can replace conventional measurement indicators, energy meters, multifunctional power meters, and related auxiliary units. As an advanced intelligent and digital front-end acquisition component for the power grid. This instrument can be applied to various control systems, energy management systems, substation automation, distribution network automation, industrial automation, and can only be used in buildings, intelligent distribution panels, and switchgear. It has the characteristics of easy installation, simple wiring, easy maintenance, small engineering quantity, and on-site input parameter setting. Capable of networking different PLCs and industrial control computer communication software in the industry.

Main functions of the product

Detection parameters for each circuit

• Three phase voltage: UA, UB, UC

• Three phase line voltage: UAB, UBC, UCA

• Three phase current: IA, IB, IC

• Harmonic content of 32 or 52 three-phase voltage and current (customized default 32 or 52 requires special instructions)

• Active power: active power per phase and total active power

• Reactive power: reactive power per phase and total reactive power

• Apparent power: apparent power per phase and total apparent power

• Power factor: power factor per phase and total power factor

• grid frequency

• Active positive and negative electrical energy

• Four quadrant reactive power

• Voltage and current imbalance

• Zero sequence current: In

• Phase angle of three-phase power factor

• Phase angle of three-phase voltage

• Communication output: RS 485

Technical Specifications

Programming and usage

1. Startup page description

The startup page can be customized with simple display content (such as company name) according to needs

2. Button Function Description (optional with button function)

Left shift key: In programming mode, when selecting a menu item, return to the previous menu, and when setting data, select which digit to change.

Reduce key: In programming mode, when selecting a menu item, select up in the same level menu. When setting data, subtract 1 from the current digit

Add key: In programming mode, when selecting a menu item, press down on the same level menu, and when setting data, increment the current digit by 1

Menu key: In the measurement display state, press this key to enter programming mode, and the instrument will prompt for the input of password (CODE). The initial password is 0001. After the password is correct, the table can be set.

display mode DSP parameter values	LCD (Liquid Crystal Display)	Instructions
Three-phase phase voltage		Display three-phase voltage values: The left image shows: A-phase voltage value: 0V B-phase voltage value: 0V C-phase voltage value: 0V DI switch input status: When there is an input corresponding to a certain channel, it will display a certain number
Three phase line voltage		Display three-phase voltage values: The left image shows: AB phase voltage value: 0V BC phase voltage value: 0V CA phase voltage value: 0V DI switch input status: When there is an input corresponding to a certain channel, it will display a certain number
three-phase current There are four circuits in total		There are four circuits in total, and the first circuit is shown in the figure Display three-phase current values The left image shows: A-phase current value: 0.000A B-phase current value: 0.000A C-phase current value: 0.000A Zero sequence current value: 0.000A
Three phase active power There are four circuits in total		There are four circuits in total, and the first circuit is shown in the figure Display three-phase active power values: The left image shows: A-phase active power value: 0W B-phase active power value: 0W C-phase active power value: 0W Total active power value: 0W
Three phase reactive power There are four circuits in total		There are four circuits in total, and the first circuit is shown in the figure Display three-phase reactive power values: The left image shows: A-phase reactive power value: 0 var B-phase reactive power value: 0 var C-phase reactive power value: 0 var Total reactive power value: 0 var
Three phase visibility active power There are four circuits in total		There are four circuits in total, and the first circuit is shown in the figure Display three-phase apparent power values: The left image shows: A-phase apparent power value: 0 VA B-phase apparent power value: 0 VA C-phase apparent power value: 0 VA Total apparent power value: 0 VA
three-phase power factor There are four circuits in total		There are four circuits in total, and the first circuit is shown in the figure Display three-phase power factor values: The left image shows: A-phase power factor value: 1.000 B-phase power factor value: 1.000 C-phase power factor value: 1.000 Total power factor value: 1.000
4-circuit current Line self inspection		The first row indicates the phase separation current of AB/C in the first circuit Reverse direction status; Normally, the page is empty behind the image on the right, If there is a phase current reversed, the corresponding phase will be displayed. If reverse is displayed, it means that the current of phase A is reversed.
Voltage phase sequence Line self inspection		The first row indicates voltage phase sequence: positive (indicating normal), reverse (indicating incorrect phase sequence connection) The last row displays the current frequency: 0.00Hz
voltage Unbalance rate		Voltage imbalance rate: 0.00%
Four circuit current Unbalance rate		Four circuit current imbalance rate: First row instructions First circuit current imbalance rate: 0.00%
Four circuits Forward, reverse active energy		There are four circuits in total, and the first circuit is shown in the figure Positive active energy: 0.00kWh Reverse active energy: 0.00kWh
Four circuits Forward, reverse Reactive energy		There are four circuits in total, and the first circuit is shown in the figure Positive reactive power of the first circuit: 0.00kvarh Reverse reactive power of the first circuit: 0.00kvarh
Four circuits Reactive power in the first quadrant Reactive power in the second quadrant		There are four circuits in total, and the first circuit is shown in the figure Reactive energy in the first quadrant: 0.01kvarh Second quadrant reactive power: 0.00kvarh
Four circuits Third quadrant reactive power Fourth quadrant reactive power		There are four circuits in total, and the first circuit is shown in the figure Reactive energy in the first quadrant: 0.00kvarh Second quadrant reactive power: 0.00kvarh

3. Menu Structure

After setting the parameters, pressSave parameters and exit

Installation and wiring

1. Appearance and installation opening size (unit: mm)

2. Installation method

According to the appearance of the instrument, select the corresponding installation hole size in the table above, open a hole on the installation plane, insert the instrument into the installation hole, place the two accessories into the installation slot of the housing, push them tightly by hand, and then fix them with installation screws

(Note: If there is any inconsistency with the wiring diagram on the instrument housing, please refer to the wiring diagram on the instrument housing.)

• Power supply:

  The working voltage range of the instrument is AC/DC 65-265 V. To prevent damage to the instrument, it is recommended to install a 1A fuse on the live side when using AC power. In areas with poor power quality, it is recommended to install surge suppressors and fast pulse group suppressors in the power circuit.

  
  

• Power signal input (current input and voltage input):

  The current input is a three-phase AC current signal input terminal of A, B, and C, where I * is the current input terminal; The voltage input is a three-phase AC voltage signal input terminal consisting of A, B, and C. Please ensure that the phase sequence and polarity of the input signal correspond one-to-one with the terminals when wiring. The input voltage should not exceed the rated input voltage of the product, otherwise PT should be considered, and a 1A fuse must be installed at the voltage input end; The input current should not exceed the rated input current of the product, otherwise an external CT should be considered. The input network n Et set in the instrument wiring and programming should be consistent with the wiring method of the measured load.

  
  

• RS 485 communication wiring

  The instrument provides an RS 485 communication interface, using the MODBUS-RTU communication protocol (see appendix). Up to 32 instruments can be connected simultaneously on a communication line, and each instrument should have a unique communication address within the line. The communication connection should use shielded twisted pair cables with copper mesh, and the wire diameter should not be less than 0 5 mm. When wiring, the communication line should be kept away from strong electrical cables or other strong electric field environments. The theoretical maximum transmission distance is 1200 meters. The typical network connection method is shown in the figure below, and users can choose other suitable connection methods according to specific situations.

MOBUS-RTU communication protocol

1. The instrument provides RS485 communication interface and adopts MODBUS-RTU communication protocol

2. Communication information transmission process

When a communication command is sent from the host to the slave, the slave that matches the address code sent by the host receives the communication command. If the CRC check is correct, the corresponding operation is performed, and then the execution result (data) is returned to the host. The returned information includes address code, function code, executed data, and CRC check code. If the CRC check is incorrect, no information will be returned.

• address code

  The address code is the first byte of each communication information frame, ranging from 1 to 247. Each slave must have a unique address code, and only the slave that matches the address code sent by the host can respond and send information. When sending information from the device, the data is sent starting with their respective address codes. The address code sent by the host indicates the address of the slave to be sent, while the address code returned by the slave indicates the address of the slave to be sent. The corresponding address code indicates where the information comes from.

  
  

• function code

  The second byte of each communication information frame. The host sends a function code to tell the slave what action should be performed. The slave responds with the same function code as the one sent from the host, indicating that the slave has responded to the host and performed the relevant operations.

  The instrument supports the following function codes:

  function code	definition	operation
  03H	Read register	Obtain the current binary value of one or more registers

  
  

• data area

  The data area varies depending on the function code. These data can be numerical values, reference addresses, etc. For different slaves, the address and data information are not the same (a communication information table should be provided).

  The host can read and modify instrument data registers freely using communication commands (function code 03H), and the length of data read at once should not exceed the valid range of data register addresses.

The process of generating a CRC is as follows:

• Pre set a 16 bit register (hexadecimal, all 1s), called the CRC register;

• XOR the first byte of the data frame with the low byte in the CRC register, and store the result in the CRC register.

• Move the CRC register to the right by one bit, fill the highest bit with 0, move the lowest bit out and check.

• If the one removed in the previous step is 0, repeat the third step (next time): 1; XOR the CRC register with a preset fixed value (0A001H);

• Repeat steps three and four until 8 shifts are made, thus completing a complete 8-bit process;

• Repeat steps two to five to process the next eight bits until all byte processing is complete;

• The final value of the CRC register is the value of the CRC

4. MODBUS_STU Address Information Table (addresses are represented by decimal numbers)

Read DI status function code as (02H)

Sent: 01 02 00 00 08 CRCL CRCH

Return: 01 02 01 07 CRCL CRCH (07 is ON for Di1, 2, and 3)

The reading method is the same as DO, but the read back is two bytes. There are a maximum of 8 inputs in the program, and the read back value is 01

Indicate the first path, 02 indicates the second path, 80 indicates the eighth path

Note: IEEE-754 uses 4-byte binary floating-point numbers to represent a data battery level, and its data format and meaning are as follows:

Sign bit: SIGN=0 is positive, SIGN=1 is negative; Index section: E=Index section -126;

Tail part: M=The tail part is supplemented with the highest digit as 1;

Data result: REAL=SIGN × 2 E × M/(256 × 65536)

For example, when the host reads energy data, it can be seen from the address table that the energy (positive active energy) address is 00 (0000H) and the length is 2 (0002 H)

Host: 01 H 03 H 00 00 H 00 02 H C 4 0 BH

Slave: 01 03H 04H 50 80 00 00H EAH DBH, where 50 80 00 00 00 is active energy (absorption) data, EBH, 6CHCRC16 low and high bits

Its size: SIGN (sign bit=0, positive), exponent EX=A 1 H -126=35, tail number: 08 00 00 H

Result: 235 × 80 00 00 H/ 100 00 00 H= 17179869184 Wh= 17179869 k Wh

5. Examples of Communication Messages

Read the three-phase current value from the slave machine with terminal device address 1 (01H).

Query data frame (host)

Response data frame (host)

Indicating: IA=43556680 H (213 4 A), IB= 43203040 H( 160 . 1 A), IC= 42 DDCC 80 H( 110 . 8 A)

Common problems and solutions

1. Regarding inaccurate measurements of U, I, P, etc

Answer: Firstly, it is necessary to ensure that the correct voltage and current signals have been connected to the instrument. A multimeter can be used to measure the voltage signal, and if necessary, a clamp meter can be used to measure the current signal. Secondly, it is necessary to ensure that the connection of the signal line is correct, such as the incoming end of the current signal and whether the phase sequence of each phase is incorrect. The multifunctional power meter can observe the power interface display. Only in the case of reverse power transmission, the active power is negative. In general, the active power sign is positive. If the active power sign is negative, it is possible that the current input line is connected incorrectly. Of course, incorrect phase sequence connection can also cause abnormal power display. Additionally, it should be noted that the electricity displayed on the instrument is the value of the primary power grid. If the multiplication ratio of the voltage and current transformers set in the instrument does not match the actual multiplication ratio of the transformers used, it can also result in inaccurate display of the instrument's electricity.

2. Regarding inaccurate spelling of electric energy and failure to save electric energy data

Answer: The accumulation of electrical energy in instruments is based on the measurement of power. First, observe whether the power value of the instrument matches the actual load. Multi functional power meters support bidirectional energy metering. In the event of wiring errors or negative total active power, the energy will accumulate to the reverse active energy, while the forward active energy will not accumulate. The most common problem encountered on site is the reverse connection of the incoming and outgoing lines of current transformers.

When the electrical energy data is not saved, please check if the instrument is under load. After adding the load, the instrument will continue to accumulate.

3. The instrument panel does not light up

Answer: Ensure that a suitable auxiliary power supply has been added to the auxiliary power terminal of the instrument. Auxiliary power supply voltage exceeding the specified range will damage the instrument and cannot be restored. A multimeter can be used to measure the voltage value of the auxiliary power supply. If the power supply voltage is normal and the instrument does not display anything, you can consider cutting off the power and powering it back on. If the instrument still cannot display normally, please contact our technical department.

Regarding RS 48 5 communication, the instrument did not send data

Answer: Firstly, ensure that the communication settings of the instrument, such as slave address, baud rate, verification method, etc., are consistent with the requirements of the upper computer. If there is no data transmission from multiple instruments on site, check whether the connection of the field communication bus is accurate and reliable, and whether the RS485 converter is normal. If only a single or a few instruments have communication abnormalities, the corresponding communication lines should also be checked. The address of the abnormal and normal instrument slave can be modified to test, eliminate or confirm software problems on the upper computer, or to test, eliminate or confirm instrument faults by changing the installation position of the abnormal and normal instruments.