DJSF866 4P single-phase rail DC meter

Overview

The DJSF866 electronic single-phase DC energy meter is a new generation of intelligent high-tech energy metering product developed and produced by our company. It is based on dedicated metering chip technology and adopts the latest integrated circuit technology. It is designed and manufactured according to relevant international (IEC) standards for electric energy meters and China's power standards DL/T614-2007 "Multi functional Electric Energy Meter", DL/T645-2007 "Multi functional Electric Energy Meter Communication Protocol", JJG 842-2017 "DC Electric Energy Meter Verification Regulations", etc. It integrates measurement, monitoring, alarm, display, freezing, RS485 communication, and infrared communication functions, realizing DC measurement of charging piles and collection and storage of electricity information.

Technical parameters and working principle

1. Technical parameters

Note: Special specifications can be customized.

2. Working principle

The circuit metering part adopts dedicated metering chips, which can accurately measure active energy. It has the characteristics of high reliability, high precision, and low power consumption. The energy meter is powered by a transformer. The metering chip converts electrical energy into pulses, which are then collected and accumulated by the CPU chip. It also performs functions such as infrared meter reading, 485 meter reading, and LCD display. The clock adopts an external professional temperature compensation chip to ensure that the daily clock error is less than 0.5S/d at the nominal temperature, and the monthly error does not exceed 25 seconds. Far infrared communication uses 38kHz modulation, with a communication distance of no less than 5 meters. Redundant design is adopted for data security, with multiple backups to ensure the reliability of measurement data.

The product principle diagram is as follows:

Basic functions

1. Electricity metering

• a) It has the function of measuring positive and negative active energy, and can set the combined active energy based on this.

• b) Optional time-sharing metering function, active electrical energy can be accumulated and stored separately according to the corresponding time period rate; And save all current electricity data, with a maximum storage capacity of December electricity data. The settlement time can be set to any hourly time on any day of the month, and the electricity settlement date can be set from the 1st to the 28th of each month.

2. Measurement and monitoring

• It can measure voltage, current, active power, etc. The measurement error (citation error) shall not exceed ± 1%.

3. Rate and Time Period (optional)

• a) Adopting a built-in hardware clock circuit with temperature compensation function, it has calendar, timing, and leap year automatic switching functions. The output frequency of the internal clock terminal is 1Hz.

• b) It has 2 sets of time zone tables and can be configured with 2 sets of time zone table switching times;

• d) It has 2 sets of daily time slot tables and can be configured with 2 sets of daily time slot table switching times;

• d) Public holiday periods can be configured.

• e) You can configure the weekend and the time slot table number for selecting weekends.

• f) It has the function of recording active power history for the past 12 months

4. Communication

• a) The electric energy meter has one infrared communication interface and one RS485 communication interface. The physical layers of infrared and RS485 communication interfaces are independent of each other, and the damage of one communication interface does not affect the normal operation of other communication interfaces. In addition, photoelectric isolation is implemented for communication interfaces and internal circuits of energy meters, with failure protection circuits.

• b) The communication baud rate can be set, with standard rates of 1200bps, 2400bps, 4800bps, and 9600bps; The default baud rate for RS485 interface is 2400bps; The default baud rate for modulated infrared communication interfaces is 1200bps.

• c) The communication protocol of the electric energy meter complies with the requirements of DL/T645-2007 and its filing documents.

5. LED indication, pulse signal output

• a) The electric meter panel is equipped with LED indicator lights for active power pulses. The power pulse constant is related to the meter specifications, and the specific values can be found on the meter nameplate.

• b) The auxiliary terminal of the electric meter is equipped with an active calibration pulse signal.

6. Electricity meter sleep mode

• When the external AC power supply is cut off, the electricity meter is powered by the internal battery to maintain uninterrupted operation, and at the same time, the electricity meter automatically enters a sleep state to reduce battery power consumption; When the external AC power supply is restored, the electricity meter exits sleep mode. Can be awakened in sleep mode.

7. LCD display

Using a wide temperature and large LCD display to show various types of information; The number of digits displayed for electric energy is 6 for integers and 2 for decimals.

Appearance and installation dimensions

(For reference only, subject to the actual product)

wiring diagram

(For reference only, subject to actual conditions)

Outline structure diagram and dimension table of external splitter

Note: When installing the external shunt, it needs to be connected in series at the "V+" position of the device. The two output leads "I+" and "I -" of the shunt should be connected to terminals 6 and 5 of the electricity meter in the order shown in the diagram. The factory default is the external splitter access method.

Precautions

• The voltage must be strictly connected according to the voltage and current levels indicated on the label.

• During installation, the wiring should be tightened and the meter should be securely hung on a sturdy, fire-resistant, and vibration resistant screen. It should be installed vertically.

• After wiring, the end cap should be sealed with lead, and it is recommended to add lead seal to the top cover of the meter.

• The meter should be stored in an environment with a temperature of -40 to 70 ℃ and a humidity of less than 85%, and should be placed in its original packaging with a stacking height of no more than 5 layers. Electric meters should not be stored after unpacking.

Communication data format

Appendix 1:

Modbus RTU communication format and communication code

1 start bit, 8 data bits, 1 even check bit, and 1 stop bit. Default baud rate 9600, even parity check. The baud rate can be changed to 120024004800. The parity bits can also be changed to no parity.

Communication code:

Appendix 2: Display Code