IEC 62271-108-2005 pdf – High-voltage switchgear and controlgear – Part 108: High-voltage alternating current disconnecting circuit-breakers for rated voltages of 72,5 kV and above.
1 General 1.1 Scope and object This part of IEC 62271 applies to high-voltage alternating current disconnecting circuit- breakers for operation at frequencies of 50 Hz and 60 Hz on systems having voltages of 72,5 kV and above. This standard identifies which requirements of IEC 60694, IEC 62271-100 and IEC 62271-102 standards are applicable. It also gives the additional requirements specific to these devices. This standard covers a circuit-breaker which, when in the open position, satisfies the requirements of both a circuit-breaker and a disconnector. As there is interaction between the requirements of the separate functions it is necessary to consider the standardisation of requirements. This standard details the requirements for a disconnecting circuit-breaker, identifying where these differ from the separate requirements of a discrete circuit-breaker and a disconnector. NOTE For design examples of disconnecting circuit-breakers, refer to Annex A. 1.2 Normative 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. IEC 60694:1996, Common specifications for high-voltage switchgear and controlgear standards IEC 62271-100:2001, High-voltage switchgear and controlgear – Part 100: High-voltage alternating-current circuit-breakers IEC 62271-102:2001, High-voltage switchgear and controlgear – Part 102: Alternating-current disconnectors and earthing switches IEC 62271-310:2004, High-voltage switchgear and controlgear – Part 310: Electrical endurance testing for circuit-breakers of rated voltage 72,5 kV and above 2 Normal and special service conditions Clause 2 of IEC 60694 is applicable.
3 Terms and definitions For the purposes of this document, the following terms and definitions apply. NOTE 1 Certain definitions taken from IEC 60050(441), IEC 60050(604) and IEC 60694 are recalled here for ease of reference. NOTE 2 Additional definitions given here are classified in a manner that aligns with the classification used in IEC 60050(441). 3.1 General terms 3.1.1 switchgear and controlgear general term covering switching devices and their combination with associated control, measuring, protective and regulating equipment, also assemblies of such devices and equip- ment with associated interconnections, accessories, enclosures and supporting structures [IEV 441-11-01] 3.2 Assemblies of switchgear and controlgear No particular definitions. 3.3 Parts of assemblies No particular definitions. 3.4 Switching devices 3.4.101 circuit-breaker mechanical switching device, capable of making, carrying and breaking currents under normal circuit conditions and also making, carrying for a specified time and breaking currents under specified abnormal circuit conditions such as those of short circuit [IEV 441-14-20] 3.4.102 disconnector mechanical switching device which provides, in the open position, an isolating distance in accordance with specified requirements [IEV 441-14-05] 3.4.103 disconnecting circuit-breaker circuit-breaker satisfying the requirements of a disconnector, when the contacts are in open position 3.5 Parts of switchgear and controlgear No particular definitions.
3.6 Operation 3.6.101 closed position (of a mechanical switching device) position in which the predetermined continuity of the main circuit of the device is secured [IEV 441-16-22] 3.6.102 open position (of a mechanical switching device) position in which the predetermined clearance between open contacts in the main circuit of the device is secured [IEV 441-16-23] 3.6.103 interlocking device device which makes the operation of a switching device dependent upon the position of operation of one or more other pieces of equipment [IEV 441-16-49] 3.7 Characteristic quantities 3.7.101 insulation level for a disconnecting circuit-breaker, a characteristic defined by one or two values indicating the insulation withstand voltages [IEV 604-03-47, modified] 3.7.102 external insulation distances in atmospheric air, and surfaces of solid insulation of disconnectors and earthing switches in contact with the air, which are subject to dielectric stresses and to the effect of atmospheric and other external conditions such as pollution, humidity, vermin, etc. [IEV 604-03-02, modified] NOTE External insulation is either weather-protected or non-weather-protected, designed to operate outside or inside closed shelters, respectively 3.7.103 internal insulation internal solid, liquid or gaseous parts of the insulation of equipment which are protected from the effects of atmospheric and other external conditions [IEV 604-03-03] 3.7.104 isolating distance (of a pole of a mechanical switching device) clearance between open poles meeting the safety requirements specified for disconnectors [IEV 441-17-35, modified]