Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
GB/T 7251 Low-voltage switchgear and controlgear assemblies consists of the following nine parts:
— Part 1: General rules;
— Part 2: Power switchgear and controlgear assemblies;
— Part 3: Distribution boards intended to be operated by ordinary persons (DBO);
— Part 4: Particular requirements for assemblies for construction sites (ACS);
— Part 5: Assemblies for power distribution in public networks;
— Part 6: Busbar trunking systems (busways);
— Part 7: Assemblies for specific applications such as marinas, camping sites, market squares, electric vehicles charging stations;
— Part 8: General technical requirements for intelligent assembly
— Part 10: Guidance to specifying assemblies;
This part is Part 8 of GB/T 7251.
This part is developed in accordance with the rules given in GB/T 1.1-2009.
This part replaces GB 7251.8-2005 Low-voltage switchgear and controlgear assemblies — General technology requirement for intelligent assemblies.
The following main technical changes have been made with respect to GB/T 7251.8-2005:
— rearrangement of the overall structure;
— modification of the definition of “intelligent assembly” (see 3.1; 3.1 in Edition 2005);
— revision to the requirements of communication mode, four remote functions, system configuration and system software (see 8.2, 8.4.3 and 8.4.4, and 5.2, 5.4.3 and 5.4.4 of the Edition 2005);
— modification to the verification method that changed the type test and ex-factory test into design verification and routine inspection (see Clauses 10 and 11, and Clause 7 of Edition 2005);
— revision to the additional requirements of assembly using Modbus, DeviceNet and Profibus buses in the Annex (see Annex A, Annex B and Annex D, and Annex A, Annex B and Annex C of Edition 2005);
— addition of additional requirements for assembly using Modbus TCP/IP mode (see Annex A);
— addition of additional requirements for assembly using Ethernet/IP mode (see Annex C).
This standard was proposed by the China Electrical Equipment Industrial Association.
This standard is under the jurisdiction of National Technical Committee 266 on Low-voltage Switchgear and Controlgear Assemblies of Standardization Administration of China (SAC/TC 266).
The previous edition of this part is as follows:
— GB/T 7251.8-2005.
Low-voltage switchgear and controlgear assemblies — Part 8: General technical requirements for intelligent assembly
1 Scope
This part of GB/T 7251 specifies the terms and definitions, service conditions, structural requirements, performance requirements and verification requirements of intelligent assemblies of low-voltage switchgear and controlgear assemblies.
This part is applicable to intelligent assemblies with rated voltage not exceeding 1 000 V AC, frequency not exceeding 1 000 Hz and DC voltage not exceeding 1 500 V.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated reference, only the edition cited applies. For undated references, the latest edition of the referenced documents (including any amendments) applies.
GB/T 7251.1-2013 Low-voltage switchgear and controlgear assemblies — Part 1: General rules
GB/T 17626.4-2018 Electromagnetic compatibility — Testing and measurement techniques — Electrostatic discharge immunity test
GB/T 17626.4-2018 Electromagnetic compatibility — Testing and measurement techniques — Electrical fast transient/burst immunity test
GB/T 17626.5-2008 Electromagnetic compatibility — Testing and measurement techniques — Surge immunity test
GB 18858.3-2012 Low-voltage switchgear and controlgear — Controller-device interface(CDIs) — Part 3: DeviceNet
GB/T 19582.2-2008 Modbus industrial automation network specification — Part 2: Modbus protocol implementation guide over serial link
GB/T 25919.1 Modbus test specification — Part 1: Modbus conformance test specification over serial link
GB/T 25919.2 Modbus test specification — Part 2: Modbus interoperability test specification over serial link
GB/T 35673-2017 Industrial communication networks — Network and system security — System security requirements and security levels
IEC 61158 (All Parts) Industrial communication networks — Fieldbus specifications
IEC 61784 (All Parts) Industrial communication networks — Profiles
IEC 62591 Industrial networks Wireless communication network and communication profiles — WirelessHARTTM
IEC 62601 Industrial networks — Wireless communication network and communication profiles — WIA-PA
IEC 62734 Industrial networks — Wireless communication network and communication profiles — ISA 100.11a
IEC 62948 Industrial networks — Wireless communication network and communication profiles — WIA-FA
IEEE 802.3 IEEE standards for information technology — Telecommunications and information exchange between systems — Local and metropolitan area networks — Specific requirements — Part 3: Carrier sense multiple access with collision detection (CSMA/CD) access method and physical layer specifications
IEEE 802.11 Wireless local area networks
IEEE 802.15 Wireless specialty networks (WSN)
IEEE 1588 Precision clock synchronization protocol for networked measurement and control systems
3 Terms and Definitions
For the purposes of this document, the terms and definitions given in GB/T 7251.1-2013 and the following apply.
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
4 Symbols and abbreviations
For the purposes of this document, the definitions and abbreviations given in Clause 4 of GB/T 7251.1-2013 apply.
5 Interface characteristics
They shall meet the requirements specified in GB/T 7251.1-2013, Clause 5.
6 Information
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.
7 Service conditions
They shall meet the requirements specified in GB/T 7251.1-2013, Clause 7.
8 Structural requirements
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.
Foreword I
1 Scope
2 Normative References
3 Terms and Definitions
4 Symbols and abbreviations
5 Interface characteristics
6 Information
7 Service conditions
8 Structural requirements
9 Performance requirements
10 Design verification
11 Routine inspection
Annex A (Normative) Additional requirements for assemblies using Modbus buses
Annex B (Normative) Additional requirements for assemblies using DeviceNet buses
Annex C (Normative) Additional requirements for using Ethernet/IP network assemblies
Annex D (Normative) Additional requirements for assembly using Profibus-DP bus
Bibliography
