The APM521 network power meter is designed according to IEC international standards and has functions such as full energy measurement, energy statistics, energy quality analysis event recording, and network communication. It is mainly used for comprehensive monitoring of power supply quality in the power grid. This series of instruments is equipped with feature rich DI/DO modules and AO modules, which can flexibly achieve full power measurement and switch status monitoring of electrical circuits. Dual directional metering meter with UL certification
introduction:
The APM521 network power meter is designed and built in strict accordance with IEC international standards, with rich functions such as accurate measurement of full power, comprehensive statistics of electrical energy, in-depth analysis of electrical energy quality, event recording, and network communication. It is mainly used for comprehensive monitoring of power supply quality in the power grid. This series of instruments is equipped with fully functional DI/DO modules and AO modules, which can flexibly and efficiently achieve full power measurement of electrical circuits and real-time monitoring of switch status.
Against the backdrop of accelerated energy management and surging smart grid construction, smart meters with international certification have become an emerging growth engine in the field of power equipment exports. For enterprises, selecting products that have passed * * certification is not a simple market choice, but a "ticket" to enter * * markets such as North America and the European Union. It is also a strategic key to shaping brand reputation and ensuring long-term stable cooperation. Among them, UL certification, as a widely accepted safety standard in the North American market, works hand in hand with the CE certification of the European Union to jointly build the core compliance barrier for products to move towards internationalization.

1、 Application scenarios of electric meters
Commercial buildings, such as office buildings, shopping malls, hotels, etc., are used to accurately measure electricity consumption for cost accounting and energy management.
Industrial facilities: factories, workshops, and other places that monitor the electricity usage during the production process, helping optimize equipment operation and energy efficiency.
Data center: Accurately measure and monitor the power consumption of servers, network equipment, etc., to ensure the stability and reliability of power supply.
In the field of new energy, such as solar power plants, wind farms, etc., they are used to measure the generated electricity and the interaction with the power grid.
Public facilities: including hospitals, schools, sports centers, etc., to ensure reasonable allocation and management of electricity usage.
Charging station: used for electric vehicle charging stations to accurately measure the energy consumption during the charging process.
Smart Grid: As a part of the smart grid system, it enables remote meter reading, power monitoring, and control functions.
Residential communities: Measure and manage the electricity usage of residential buildings to facilitate the collection of electricity bills and energy consumption analysis.
3、 Function Introduction
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measurement parameters
Measured
parameters
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Full power measurement
Total electrical measurement
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Four quadrant electrical energyFour quadrant reactive energy, phase separated energy, apparent energyMultiple rate electricity
Four-quadrant energyTheFour - quadrant reactive electric energyTheSplit phase electricityTheApparent energyTheMulti-rate energy
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pulse output
Pulse output
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Total active and reactive power pulse output
Total active power, total reactive power electrical energy pulse output
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demand
Demand
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Three phase currentmeritoriousPowerno meritPowerapparentReal time power demand and maximum demand(Include timestamp)Last month's maximum demand(Include timestamp)
Three-phase current, active power, reactive power, apparent power real-time demand and maximum demand (including timestamp), last month's maximum demand (including timestamp).
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Extreme value statistics
Extreme
value statistics
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Currentline voltage、phaseVoltagemeritoriousPowerno meritExtreme values of power and other electrical parameters for this month and last month(Include timestamp)
Current, line voltage, phase voltage, active power, reactive power and other electrical parameters extreme values of this month and last month (including time stamps)
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power quality
Power quality
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Current, line voltagephaseVoltage imbalance
Unbalance of current, line voltage, phase voltage
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Voltage phase angle, current phase angle
Voltage phase angle, current phase angle
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Voltage and current total(Odd, even)harmonic content
Total (odd, even) harmonic content of voltage and current
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Voltage and current subharmonics(2-63time)content
Harmonic content of voltage and current (2-63 times)
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Voltage peak coefficient
Voltage peak coefficient
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Telephone waveform factor
Telephone waveform factor
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currentKcoefficient
Current K-factor
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vector graphic
Vector
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Real time waveform of voltage and current
Voltage and current waveform
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Fundamental voltage, fundamental current, fundamental power factor
Fundamental voltage ,current and power factor
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Voltage deviation, frequency deviation
Voltage deviation, frequency deviation
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Positive, negative, and zero sequence voltages
Positive - sequence voltage, negative - sequence voltage, zero - sequence voltage
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Positive, negative, and zero sequence currents
Positive - sequence current, negative - sequence current, zero - sequence current
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Freeze electrical energy
Frozen electric energy
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 24Freeze electrical energy31Daily frozen electricity12Monthly freezing of electrical energy, timed freezing of electrical energy
24 - hour frozen electric energy, 31 - day frozen electric energy, December frozen electric energy, regular - time frozen electric energy
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Event log
Event logging
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DIDORecord, can record the most recent128itemDIDOrecord
DIDO records, which can record the last 128 DID records
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police record
Alarm logging
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Can record recent events128Alarm records
The last 128 alarm records can be recorded
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communication
Communication
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Modbus - RTUAgreementDL/T 645-2007specification
Modbus - RTU protocol, DL/T 645-2007 statute
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Optional features
Optional features
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4Road switch input,2Road switch output
4-channel digital input and 2-channel digital output
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2Analog output,4-20mA
2 channels of analog output, 4-20mA
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Expand the second pathRS485communication,Modbus - RTUagreement
Expand the second RS485 communication channel with Modbus - RTU protocol
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Expand Ethernet communication,MODBUS-TCPagreement,FTPagreement
Expand Ethernet communication with the MODBUS-TCP protocol,FTP protocol
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4、 Electrical technical parameters
project Item |
performance parameters Performance Parameters |
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voltage Voltage |
rated voltage
(ULTheCE) Rated voltage(ULTheCE)
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66V AC L-N 115V AC L-L
230V AC L-N 400V AC L-L
277V AC L-N 480V AC L-L
400V AC L-N 690V AC L-L
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rated voltage(CPA) Rated voltage
(CPA)
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three-phase three-wire
3P3L
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three-phase four-wire
3P4L
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3x100V
3x380V
3x690V
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3x57.7/100V
3x220/380V
3x400/690V
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overload Overload |
1.2 Multiple rated value (continuous) 1.2 times rating (continuous)
2 Continuous double rated value1 second
2 times the rating for 1 second
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power consumption Power consumption |
<1VA |
accuracy class Accuracy class |
error±0.2% Error ±0.2% |
current Current |
ratedcurrent
(ULTheCE) Rated current(ULTheCE)
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1AThe5A |
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ratedcurrent
(CPA) Rated current
(CPA)
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0.015-0.075(6)A(Active electrical energy)Active energy)
3X1(6)A(Reactive energy)Reactive energy)
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overload Overload |
1.2 Multiple rated value (continuous) 1.2 timesrating (continuous)
10 Continuous double rated value 1 second 10times the rating for 1 second
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power consumption Power consumption |
<0.2VA |
accuracy class Accuracy class |
error±0.2% Error ±0.2% |
power Power |
Active, reactive, apparent power, error±0.2% Active, reactive, apparent power, error ±0.2% |
grid frequency Grid frequency |
ULTheCE |
50Hz/60HzError±0.2% 50Hz/60Hz, error ±0.2% |
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CPA |
50HzError±0.2%
50Hz,error ±0.2%
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response rate Response rate |
≤200ms(Voltage, current, power) ≤200ms (voltage, current, power) |
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≤1s(Electricity) ≤1s (electrical energy) |
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Measurement category
Measurement category
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66ULN(+20%) 115ULL(+20%) CATⅢ
230ULN(+20%) 400ULL(+20%) CATⅢ
277ULN(+20%)480ULL(+20%) CATⅢ
400ULN(+20%) 690ULL(+20%) CATⅡ
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measurement Metering |
electric energy Electric energy |
active energy:Dlevel
Active energy:Class D
Reactive energy (accuracy level)2level) Reactive energy (Class 2 accuracy)
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auxiliary power supplyAuxiliary power supply |
AC/DC 85-300V |
Electromagnetic Compatibility electromagnetic compatibility |
Electrostatic discharge immunityIV level Electrostatic discharge immunity class IV |
Electrical fast transient burst immunityIVlevel Electrical fast transient burst immunity class IV |
surge(impact)ImmunityIVlevel Surge (shock) immunity Class IV |
safety Security |
power frequency withstand voltage Power frequency withstand voltage |
Between communication and signal inputAC4kV 1min Between communication and signal input,AC4kV 1min |
insulation resistance Insulation resistance |
Input and output terminals to the casing>100MΩ Input and output terminals to casing >100MΩ |
communication Communication |
Interface and Communication Protocol Interface and communication protocol |
RS485口、Modbus RTUspecification RS485 interface and Modbus RTU protocol |
Communication address range Communication address range |
Modbus RTU:1~ 247; |
Baud rate Baud rate |
support1200bps-38400bps Support 1200bps-38400bps |
environment Environment |
Operating Temperature Operating temperature |
-40℃~+70℃ |
Storage temperature Storage temperature |
-40℃~+80℃ |
relative humidity Relative humidity |
≤95%(No condensation) ≤95%(without condensation) |
altitude Altitude |
≤2000m |
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≥2000m,≤5000m(For power supply only)AC/DC85-265V, voltage277/480VBelow)
≥2000m,≤5000mOnly applicable to the power supply with the voltage range of AC/DC 85-265V and the voltage below 277/480V.
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Installation environment
Installation environment
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Indooruse |
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pollution level
Pollution degree
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Class2 |
5、 Installation and wiring
5.1 Overall dimensions

5.2 Wiring guidance

6、 Conclusion
Dual directional metering meter with UL certificationWith its outstanding safety performance, complete functional system, and diverse application scenarios, it stands out in the field of power monitoring, demonstrating significant advantages and broad development potential. It not only provides accurate and stable data support for power management in different industries, but also utilizes Ethernet communication technology to move the power system towards a new stage of intelligent development. With the rapid development of technology and the continuous increase in energy management demand, UL certified Ethernet communication meters are expected to make great strides in a wider range of fields, effectively promoting the power industry to steadily move towards safer, more efficient, and smarter directions. For the vast number of users, it is important to have a deep understanding and make scientific choicesExport UL certified electric metersWe will effectively improve the level of power management and help achieve the goals of energy conservation, emission reduction, and sustainable development.
Dual directional metering meter with UL certification