GB/T 20840.8-2007
Instrument transformers Part 8: Electronic current transformers (English Version)

Standard No.

GB/T 20840.8-2007

Language

Chinese, Available in English version

Release Date

2007

Published By

General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China

Latest

GB/T 20840.8-2007

Scope

This part applies to newly manufactured electronic current transformers, which have analog voltage output or digital output, and are used by electrical measuring instruments and relay protection devices with a frequency of 15Hz to 100Hz. The accuracy requirements listed in Chapter 12 apply to electronic current transformers for electrical measuring instruments. The accuracy requirements listed in Chapter 13 are applicable to electronic current transformers for relay protection devices, especially those protection methods whose main requirement is to maintain accuracy when the current reaches many times the rated current. When required, the transient accuracy of electronic current transformers during power system faults is also listed in this chapter. Electronic current transformers for both measurement and protection purposes shall comply with all the provisions of this standard and are referred to as multi-purpose electronic current transformers. This transformer technology can use optical devices with electronics, air core coils (with or without built-in integrators) or iron core coils with built-in shunt resistors as converters of electrorheological voltage, which can be used alone or with electronics . For analog outputs, electronic current transformers may include secondary signal cables. The technical examples of electronic current transformers using hollow wire diagrams and core coils with built-in parallel resistors are listed in Appendix D. For digital output, this section adopts electronic transformers to electrical measuring instruments and electrical devices as point-to-point links (see Appendix E). In order to ensure the compatibility of this point-to-point link with the entire substation communication system, thereby allowing data exchange between all types of substation devices, some additions were made. These establish the link-layer mapping of what is called a point-to-point serial link. Bus communication is under consideration. This mapping allows devices from different manufacturing units to be used interoperably. This section neither specifies a specific implementation or product, nor does it limit various implementations and interfaces of computer systems. This section specifies the externally visible functions of various implementations, and the requirements to which these functions are subject.

GB/T 20840.8-2007 Referenced Document

• GB 1208-2006 Current transformers
• GB 1984 High-voltage alternating-current circuit-breakers*， 2014-06-24 Update
• GB 311.1-1997 Insulation co-ordination for high voltage transmission and distribution equipment
• GB 4208 Degrees of protection provided by enclosure(IP code)*， 2008-03-25 Update
• GB 4824-2004 Industrial,scientific and medical(ISM)radio-frequency equipment-Electromagnetic disturbance characteristics-Limits and methods of measurement
• GB 5585.1-1985 Copper or aluminium and its alloy bus bars for electrical purposes--Part 1:General
• GB 6995.1-1986 Markings for electric cables and wires--Part 1:General requirements
• GB 6995.2 Markings for electric cables and wires--Part 2:Standard colours
• GB/T 2423.10-1995 Environmental testing for electric and electronic products. Part 2: Test methods. Test Fc and guidance: Vibration (Sinusoidal)
• GB/T 2423.23-1995 Environmental testing for electric and electronic proucts. Test Q: Sealing
• GB/T 2900.15-1997 Electrotechnical terminology. Transformer, instrument transformer, voltage regulator and reactor
• GB/T 2900.57-2002 Electrotechnical terminology--Generation,transmission and distribution of electricity--Operation
• GB/T 3954 Aluminium and aluminium alloys rod for electrical purpose*， 2022-12-30 Update
• GB/T 4365-2003 Electrotechnical terminology Electromagnetic compatibility
• GB/T 4798.3-1990 Environmental conditions existing in the application for electric and electronic products--Stationary use at weather-protected locations
• GB/T 4798.4-1990 Environmental conditions existing in the application for electric and electronic products--Stationary use at non-weather-protected locations
• GB/T 5465.2 Graphical symbols for use on electrical equipment.Part 2: Graphical symbols*， 2008-05-20 Update

GB/T 20840.8-2007 history

• 2007 GB/T 20840.8-2007 Instrument transformers Part 8: Electronic current transformers

GB/T 20840.8-2007 -All Parts