GB/T 7251.8-2020Low-voltage switchgear and controlgear assemblies—Part 8: General technical requirements for intelligent assembly (English PDF)

3.1 intelligent assembly

new assembly which is designed to achieve intelligent operation and maintenance in the full life cycle by using advanced technology in sensor, digitization, network, communication, artificial intelligence (AI) and others

Note to entry: To realize all or part of functions of remote measurement, remote information, remote control and remote adjustment to slaves through the master, intelligent assemblies have the specific features include but are not limited to:

— On-line monitoring of the environmental temperature and humidity of the assemblies and the temperature of key parts or key units of the assemblies;

— Intelligent prewarning, such as service life warning, fault warning, overtemperature warning, overcurrent warning and leakage warning;

— Intelligent linkage protection function;

— Functions of intelligent fault analysis, intelligent data statistics and intelligent data storage;

— Iintelligent reminder, such as reminding service for regular maintenance;

— Function of real-time video monitoring of the overall running state of the assemblies, and may also monitor the necessary parts in the assemblies in real time;

— Convenience that it may not only monitor the electrical parameters and the running status of assemblies at the master, but also quickly view the relevant information of components (such as brand, model, electrical performance parameters, etc.);

— Stable communication and data security: communication equipment and cables shall have good electromagnetic compatibility, and data transmission and storage shall be safe and reliable;

— Standard and open communication protocols;

— Assemblies and units that are compact in structure and flexible and convenient to install.

3.2 master

active communication entity capable of initiating and dispatching communication activities of other stations (possibly master or slave)

[GB/T 34040-2017, Definition 3.1.25]

3.3 slave

passive communication entity that can receive messages and send messages in response to other communication entities (master or slave)

[GB/T 34040-2017, Definition 3.1.51]

3.4 gateway

switching device for data exchange between different buses

3.5 fieldbus

communication system based on serial data transmission and applied in industrial automation or process control

[GB/T 34040-2017, Definition 3.1.18]

3.6 Industrial Ethernet

area and unit network based on IEEE 802.3 (Ethernet)

3.7 remote measurement

measure the parameters of the slave remotely by means of communication

3.8 remote information

record, store and print out the operation and faults of the slave remotely by means of communication

3.9 remote control

operate and control the slave remotely by means of communication

3.10 remote adjustment

adjust the parameters of the slave remotely by means of communication

6.1 General requirements

In addition to the provisions of GB/T 7251.1-2013, Clause 6, the following requirements in 6.2 and 6.3 herein shall also be met.

6.2 Designated marking of assembly

Besides meeting the requirements of 6.1 in GB/T 7251.1-2013, the assemblies shall also be marked with “GB/T 7251.8” and the information of the specific functions (such as remote measurement and remote information) of the “Four Remotes” on the nameplate.

6.3 Information of intelligent system

The manufacturer of assemblies shall provide instructions on special conditions for the use of assemblies and requirements for installation, operation and on-site wiring; as well as instructions for intelligent components such as communication cable interface and intelligent motor controller, embedded software, version number of communication protocol and relevant information and standards in use.

8.1 General requirements g

In addition to the provisions of GB/T 7251.1-2013, Clause 8, the following requirements in 8.2 to 8.5 herein shall also be met.

8.2 Functional requirements

8.2.1 Communication mode

The communication mode of intelligent assembly shall adopt wired communication mode with cable or optical fiber as media, such as fieldbus conforming to IEC 61158 (All Parts) and IEC 61784 (All Parts) or industrial Ethernet conforming to IEC 61158 (All Parts) and IEC 61784 (All Parts); or a wireless communication mode, such as a wireless fieldbus meeting the requirements of IEC 62591, IEC 62601, IEC 62734 and IEC 62948, Wi-Fi meeting the requirements of IEEE 802.11, ZigBee meeting the requirements of IEEE 802.15 or cellular network (3G/4G/5G), etc. See Annex A, Annex B, Annex C and Annex D for additional requirements of several typical communication protocols.

Note: With the development of industrial network technology, communication protocols are not limited to the above protocols.

8.2.2 Remote measurement function

Parameters of each circuit and slave (control unit) may be measured remotely by the upper computer:

a) Main incoming circuit: three-phase current, three-phase voltage (phase voltage/line voltage), active power, active energy, reactive energy, harmonic THD, switching times, tripping times, short-circuit breaking current, etc.;

b) Distribution circuit: three-phase current, three-phase voltage (phase voltage/line voltage), active energy, reactive energy, harmonic THD, switching times, tripping times, short-circuit breaking current, etc.

c) Power lighting: three-phase current, harmonic THD, switching times, tripping times, short-circuit breaking current, etc.;

d) Motor circuit: three-phase/single-phase current, three-phase voltage (phase voltage/line voltage), motor temperature, power factor, active power, start-up times and time intervals, running time, motor heat capacity, releasing time, reset time, contact temperature, contactor control voltage, etc.

e) Compensating circuit: three-phase voltage (phase voltage/line voltage), power factor, etc.;

f) Others: line frequency, harmonics, temperature information of key points in the cabinet, temperature/smoke/smell information of the cabinet environment, fault waveform capture, fault location analysis, etc.

The specific parameters of remote measurement shall be determined according to the needs of users. The accuracy of each parameter of remote measurement shall be determined by negotiation between the manufacturer and the user of the assembly, and the accuracy level of the electric quantity parameter shall not be lower than Level 1.0.

8.2.3 Remote information function

Various information resources of the system may be provided by the upper computer:

a) Network communication status, switch status, alarm, fault identification, motor circuit operation times/running time, etc.;

b) Inquiries, records, daily reports, etc. of various information resources;

c) Electric power management, power quality and load analysis, etc.;

d) When RS232 and RS485 communication interfaces are used, the transmission rate of 2 400 bit/s, 9 600 bit/s and 19 200 bit/s should be preferred, and the transmission rate of 10/100 Mbit/s should be preferred for the adoption of Ethernet interface.

The specific remote information functions shall be determined according to the needs of users.