This standard is applicable to a.c. circuit-breakers designed for indoor or outdoor installation and for operation at frequency of 50Hz on systems having voltages above 3,000V.
It is only applicable to three-pole circuit-breakers for use in three-phase systems and single-pole circuit-breakers for use in single-phase systems. Two-pole circuit-breakers for use in single-phase systems and application at frequencies lower than 50Hz are subject to agreement between manufacturer and user.
This standard is also applicable to the operating devices of circuit-breakers and to their auxiliary equipment. However, a circuit-breaker with a closing mechanism for dependent manual operation is not covered by this standard, as a rated short-circuit making current cannot be specified, and such dependent manual operation may be objectionable because of safety considerations.
Rules for circuit-breakers with an intentional non-simultaneity between the poles are given in GB/T 30846-2014; circuit-breakers providing single-pole auto-reclosing are within the scope of this standard.
Note 1: Circuit-breakers with an intentional non-simultaneity between the poles may, in some instances, be tested in accordance with this standard. For example, mechanically staggered pole designs may be tested according to this standard using three-phase direct tests. For synthetic testing, determining the most appropriate tests, particularly in respect to test current, recovery voltage and transient recovery voltage, is subject to agreement between manufacturer and user.
This standard does not cover circuit-breakers intended for use on motive power units of electrical traction equipment; these are covered by IEC 60077 [1] .
Generator circuit-breakers installed between generator and step-up transformer are not within the scope of this standard.
Switching of inductive loads is covered by GB/T 29489-2013.
Self-tripping circuit-breakers with mechanical tripping devices or devices which cannot be made inoperative may refer to this standard.
Circuit-breakers installed as by-pass switches in parallel with line series capacitors and their protective equipment are not within the scope of this standard. These are covered by GB/T 28565-2012 and IEC 60143-2[3].
Note 2: Tests to prove the performance under abnormal conditions shall be subject to agreement between manufacturer and user. Such abnormal conditions are, for instance, cases where the voltage is higher than the rated voltage of the circuit-breaker, conditions which may occur due to sudden loss of load on long lines or cables.
1.2Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 311.2-2013 Insulation Co-ordination - Part 2: Application Guide (IEC 60071-2:1996, MOD)
GB/T 762-2002 Standard Current Ratings(eqv IEC 60059:1999)
GB 1985-2004 High-voltage Alternating-current Disconnectors and Earthing Switches (IEC 62271-102:2002, MOD)
GB 2536-2011 Fluids for Electrotechnical Applications - Unused Mineral Insulating Oils for Transformers and Switchgear (IEC 60296:2003, MOD)
GB/T 2900.20-1994 Electrotechnical Terminology - High-voltage Switchgear (neq IEC 60050-441:1984)
GB/T 2900.50-2008 Electrotechnical Terminology - Generation, Transmission and Distribution of Electricity - General (IEC 60050-601:1985, MOD)
GB/T 2900.57-2008 Electrotechnical Terminology - Generation, Transmission and Distribution of Electricity - Operation (IEC 60050-604:1987, MOD)
GB/T 4109-2008 Insulated Bushings for Alternating Voltages above 1,000V (IEC 60137 Ed.6.0, MOD)
GB 4208-2008 Degrees of Protection Provided by Enclosure (IP Code) (IEC 60529:2001, IDT)
GB/T 4473-2008 Synthetic Testing of High-voltage Alternating Current Circuit-breakers (IEC 62271-101:2006, MOD)
GB 7674-2008 Gas-insulated Metal-enclosed Switchgear for Rated Voltages of 72.5kV and above (IEC 62271-203:2003, MOD)
GB/T 8905-2012 The Guide for Processing and Measuring SF6 Gas in Power Apparatus (IEC 60480:2004, MOD)
GB/T 11022-2011 Common Specifications for High-voltage Switchgear and Controlgear Standards (IEC 62271-1:2007, MOD)
GB/T 12022-2006 Sulphur Hexafluoride for Industrial Use (IEC 60376:1971; IEC 60376A:1973; IEC 603768:1974, MOD)
GB/T 14598.7-1995 Electrical Relays - Part 3: Single Input Energizing Quantity Measuring Relays with Dependent or Independent Time (idt IEC 60255-3:1989)
GB/T 16927.1-2011 High Voltage Test Techniques - Part 1: General Definitions and Test Requirements (IEC 60060-1:2010, MOD)
GB/T 28565-2012 High-voltage Alternating-current Series Capacitor By-pass Switches (IEC 62271-109:2008, MOD)
GB/T 29489-2013 Inductive Load Switching for High-voltage Alternating Current Switchgear and Controlgear (IEC 62271-110:2009, MOD)
GB/T 30846-2014 High-voltage Alternating Current Circuit-breakers with Intentionally Non-simultaneous Pole Operation (IEC/TR 62271-302:2010, MOD)
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