IEC 62271-107-2005 pdf – High-voltage switchgear and controlgear – Part 107: Alternating current fused circuit-switchers for rated voltages above 1 kV up to and including 52 kV.
1 General 1.1 Scope This part of IEC 62271 applies to three-pole operated units for distribution systems that are functional assemblies of a circuit-switcher and current-limiting fuses designed so as to be capable of: – breaking, at the rated recovery voltage, any load or fault current up to and including the rated short-circuit breaking current; – making, at the rated voltage, circuits to which the rated short-circuit breaking current applies. They are intended to be used for circuits or applications requiring only a normal mechanical and electrical endurance capability. Such applications cover protection of HV/LV transformers for instance, but exclude distribution lines or cables, as well as motor circuits and capacitor bank circuits. Short-circuit conditions with low currents, up to the fused circuit-switcher rated take-over current, are dealt with by supplementary devices (strikers, relays, etc.), properly arranged, tripping the circuit-switcher. Fuses are incorporated in order to ensure that the short-circuit breaking capacity of the device is above that of the circuit-switcher. NOTE 1 In this standard the term “fuse” is used to designate either the fuse or the fuse-link where the general meaning of the text does not result in ambiguity. This standard applies to fused circuit-switchers designed with rated voltages above 1 kV up to and including 52 kV for use on three-phase alternating current systems of either 50 Hz or 60 Hz. Comparison with other existing switching devices is provided in Clause 8. NOTE 2 Other circuit-switchers exist; see reference  of the bibliography. Fuses are covered by IEC 60282-1. Earthing switches forming an integral part of a circuit-switcher are covered by IEC 62271-102. Installation in enclosure, if any, is covered either by IEC 62271-200 or by IEC 60466. 1.2 Normative references The following referenced documents are indispensable for the application of this document.
IEC 60050(441), International Electrotechnical Vocabulary (IEV) – Chapter 441: Switchgear, controlgear and fuses IEC 60265-1: High-voltage switches – Part 1: Switches for rated voltages above 1 kV and less than 52 kV IEC 60282-1: 2002, High-voltage fuses – Part 1: Current-limiting fuses IEC 60466: A.C. insulation-enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 38 kV IEC 60694: Common specifications for high-voltage switchgear and controlgear standards IEC 60787: Application guide for the selection of fuse-links of high-voltage fuses for transformer circuit applications IEC 62271-100: High-voltage switchgear and controlgear – Part 100: High-voltage alternating- current circuit-breakers IEC 62271-102: High-voltage switchgear and controlgear – Part 102: Alternating current disconnectors and earthing switches IEC 62271-105: High-voltage switchgear and controlgear – Part 105: Alternating current switch-fuse combinations IEC 62271-200: High-voltage switchgear and controlgear – Part 200: A.C. metal-enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV 2 Normal and special service conditions Clause 2 of IEC 60694 is applicable. 3 Terms and definitions For the purposes of this document, the terms and definitions of IEC 60050(441) and IEC 60694 apply. Some of them are recalled here for ease of reference. The definitions given below are also applicable. Additional definitions are classified so as to be aligned with the classification used in IEC 60050(441). The definitions of IEC 60050(441) are not repeated but reference is made to their specific number. 3.1 General terms None 3.2 Assemblies of switchgear and controlgear None. 3.3 Parts of assemblies None.
3.4 Switching devices 3.4.101 circuit-switcher mechanical switching device suitable for making, carrying and interrupting currents under normal circuit conditions. It is also suitable for interrupting specified fault currents that may be less than its short-time withstand current. NOTE Other circuit-switchers exist; see reference  of the bibliography. 3.4.102 fused circuit-switcher device comprising a three-pole circuit-switcher and three current limiting fuses, capable of making and breaking any load or fault current up to its short-circuit breaking current, under TRV and power factor conditions defined in this standard 3.4.103 fused circuit-switcher base (or device base) fused circuit-switcher without fuse-links mounted 3.4.104 non-sustained disruptive discharge (NSDD) disruptive discharge associated with current interruption, that does not result in the resumption of power frequency current or, in the case of capacitive current interruption does not result in current at the natural frequency of the circuit 3.5 Parts of switchgear and controlgear 3.5.101 release [IEV 441-15-17] 3.5.102 over-current release [IEV 441-16-33] 3.5.103 shunt release [IEV 441-16-41] 3.6 Operation 3.6.101 independent manual operation (of the fused circuit-switcher) [IEV 441-16-16] 3.6.102 stored energy operation (of the fused circuit-switcher) [IEV 441-16-15] 3.7 Characteristic quantities 3.7.101 prospective current (of a circuit and with respect to a switching device or a fuse) [IEV 441-17-01]