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GB 14048.2-2008 English PDF

GB 14048.2-2008_English: PDF (GB14048.2-2008)
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GB 14048.2-2008English620 Add to Cart 0--9 seconds. Auto-delivery [GB/T 14048.2-2008] Low-voltage switchgear and controlgear -- Part 2: Circuit-breakers Obsolete GB 14048.2-2008
GB/T 14048.2-2020English3879 Add to Cart 16 days [Need to translate] Low-voltage switchgear and controlgear -- Part 2: Circuit-breakers Valid GB/T 14048.2-2020
Newer version: GB 14048.2-2020    Standards related to: GB 14048.2-2020

BASIC DATA
Standard ID GB 14048.2-2008 (GB14048.2-2008)
Description (Translated English) [GB/T 14048.2-2008] Low-voltage switchgear and controlgear. Part 2: Circuit-breakers
Sector / Industry National Standard
Classification of Chinese Standard K31
Classification of International Standard 29.120.40
Word Count Estimation 151,123
Date of Issue 2008-09-19
Date of Implementation 2009-06-01
Older Standard (superseded by this standard) GB 14048.2-2001
Quoted Standard GB/T 2423.4-2008; GB/T 2423.22-2002; GB/T 2828.1-2003; GB/T 2900.18-2008; GB 4824-2004; GB/T 5169.10-2006; GB/T 5169.11-2006; GB/T 5169.12-2006; GB/T 5169.13-2006; GB 6829-1995; GB/T 7676; GB 10963.1-2005; GB 10963.2-2003; GB 14048.1-2006; GB 14048.4-2003; GB 16895; GB 16916.1-2003; GB 16917.1-2003; GB 17701-2008; GB 17625.1-2003; GB/T 17626.2-2006; GB/T 17626.3-2006; GB/T 17626.4-2008; GB/T 17626.5-2008; GB/T 17626.6-2008; GB/T 17626.11-2008; GB/T 17626.13-2006; IEC 60068-2-14-1984; IEC 60947-1-2004; IEC 60947-4-1-2000; IEC 61000-3-2-2001; IEC 61000-3-3-2000; IEC 61000-4-3-2002; IEC/TR 61000-5-2-1997; IEC 61008-1-1996; IEC 61009-1-1996; CISPR 11-2003; CISPR 22-2005
Adopted Standard IEC 60947-2-2006, IDT
Drafting Organization Shanghai Electrical Apparatus Research Institute (Group)Co., Ltd.
Administrative Organization National Standardization Technical Committee of low-voltage electrical
Regulation (derived from) CNCA 2009 Announcement No. 32 "on the part of the implementation of the new standard for low-voltage electrical Announcement "
Proposing organization China Electrical Equipment Industry Association
Issuing agency(ies) Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China; Standardization Administration of China
Summary This Chinese standard applies to the main contact for access to the rated voltage not exceeding 1000V ac or 1500V dc circuit breaker. This standard also provides a circuit breaker with fuses Supplementary requirements. This standard applies to any rated current, a variety of structural type or intended use of a variety of circuit breakers. Used as a ground breaker protection requirements included in Appendix B. Electronic overcurrent protection circuit breaker Additional requirements included in Appendix F. Breaker for IT systems Additional requirements included in Appendix H. Breaker electromagnetic compatibility requirements and test methods are included in Appendix J. Yuan overcurrent protection circuit breaker requirements is included in Appendix L. Residual Current Devices (Internal Current Breaking Device } The requirements included in Annex M.

GB 14048.2-2008 Low-voltage switchgear and controlgear.Part 2. Circuit-breakers ICS 29.120.40 K31 National Standards of People's Republic of China GB 14048.2-2008/IEC 60947-2.2006 Replacing GB 14048.2-2001 Low-voltage switchgear and control equipment Part 2. Circuit Breaker (IEC 60947-2.2006, IDT) Posted 2008-09-19 2009-06-01 implementation Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China Standardization Administration of China released Table of Contents Preface Ⅰ 1 General 1 2 Definition 3 3 Category 6 Characteristics of the circuit breaker 7 4 5 Product Data and information 12 6 normal operation, installation and transport conditions 13 7 Structure and Performance Requirements 13 8 Test 18 Appendix A (normative) breaker and another short-circuit protection devices in series in the same circuit with the 41 in short-circuit conditions Breakers Appendix B (normative) has a residual current protection 47 Annex C (normative) unipolar circuit test program 69 Appendix D empty 70 Annex E (informative) Submit manufacturer and user consultation project 70 Additional tests Annex F (normative) with electronic overcurrent protection circuit breaker 71 Annex G (normative) Power 89 Test procedures Annex H (normative) for the IT system of the circuit breaker 91 Requirements and test methods Appendix J (normative) Electromagnetic compatibility (EMC) --- breaker 93 Annex K (informative) standards cover about 101 symbols Product Summary Annex L (normative) without over-current protection circuit breaker 103 requirements Annex M (normative) Residual Current Devices (Without Internal Current Breaking Device) 106 Annex N (normative) Electromagnetic Compatibility --- does not include the additional requirements in Appendix B, Appendix F and Appendix M of the Annex and Test 141 Appendix O (normative) instantaneous tripping circuit breaker (ICB) 144 References 146 GB 14048.2-2008/IEC 60947-2.2006 Foreword This section provisions mandatory standards. This section 7.1.3,7.1.4,7.2.1,7.2.3,7.3,8.3.3.2,8.3.3.8,8.3 .5 8.4 and Appendix B, Appendix F, Appendix J and Appendix N mandatory, the rest are recommended. With an electronic overcurrent protection circuit breaker electronic Control means EMC test is important, the electronic control unit must be manufacturers of EMC test products, such as circuit breakers factory option EMC tests have been conducted with electronic products, and has a test report, you do not have to repeat the test. This part is the "low-voltage switchgear and control equipment" Part 2, product standards, which includes the basic requirements of the circuit breaker and test method. General requirements for circuit breakers, such as general terminology, test circuits, methods prescribed in Part 1. This section must Part 1 using the binding. "Low-voltage switchgear and control equipment" includes. --- GB 14048.1 low-voltage switchgear and control equipment - Part 1. General --- GB 14048.2 low-voltage switchgear and control equipment Part 2. Circuit Breaker --- GB 14048.3 low-voltage switchgear and control equipment - Part 3. Switches, disconnectors, switch and fuse combination Electric --- GB 14048.4 low-voltage switchgear and control equipment, electromechanical contactors and motor starters --- GB 14048.5 low-voltage switchgear and control equipment Part 5-1. Control circuit devices and switching elements - Electromechanical control Electrical circuit --- GB 14048.6 low-voltage switchgear and control equipment, contactors and motor starters Section 2. AC semiconductor power Motor controller and starters --- GB/T 14048.7 low-voltage switchgear and control equipment - Part 7-1. Ancillary equipment - Terminal blocks for copper conductors --- GB/T 14048.8 low-voltage switchgear and control equipment Part 7-2. Protective conductor terminal auxiliary electrical copper conductors Terminal block --- GB 14048.9 low-voltage switchgear and control equipment Part 6-2. Multiple function equipment (equipment) electrical control and protection switch Device (equipment) (CPS) --- GB/T 14048.10 voltage switchgear and control equipment Part 5-2. Control circuit devices and switching elements proximity switch --- GB/T 14048.11 voltage switchgear and control equipment Part 6-1. Multiple function equipment - Transfer switching equipment --- GB/T 14048.12 voltage switchgear and control equipment Part 4-3. Contactors and motor starters --- non-electric Motivation load AC semiconductor controllers and contactors --- GB/T 14048.13 voltage switchgear and control equipment Part 5-3. Control circuit devices and switching elements in --- Proximity switches with defined behavior under fault conditions (PDF) requirements --- GB/T 14048.14 voltage switchgear and control equipment Part 5-5. Control circuit devices and switching elements having --- Mechanical latching function electrical emergency braking device --- GB/T 14048.15 voltage switchgear and control equipment Part 5-6. Control circuit devices and switching elements connected --- Proximity sensor and switching amplifier DC Interface (NAMUR) --- GB/T 14048.16 voltage switchgear and control equipment - Part 8. rotary motor control with built - in thermal protection (PTC) Unit This section identical with IEC 60947-2.2006 "low-voltage switchgear and control equipment Part 2. Circuit Breaker" (fourth edition in English). This part of IEC 60947-2.2006 Differences. --- 1.1 on rated voltage, IEC defined as no more than 1000V, 1140V for AC rated voltage of the circuit breaker can be Refer to this standard, performance and other requirements relating to the circuit breaker by the manufacturer and user consultation; GB 14048.2-2008/IEC 60947-2.2006 --- Taking into account national circumstances, Chapter 3, "category" in the "open style" is not reasonable, still using the usual term "universal" type, plastic shell type, also known as "Molded case" or "MCCB"; --- 8.1.2 Type tests on location, IEC regulations in the workshop or any other suitable test chamber factory was when my Otherwise provided by national laws and regulations, in accordance with relevant regulations. --- 8.3.3.3.2c) 2) regarding the maximum rated control supply voltage, IEC original 30%, the suspect is wrong, change it to 35%; --- L. 1 CBI does not provide circuit protection, especially of overload. This Part replaces GB 14048.2-2001 "Low-voltage switchgear and control equipment low voltage circuit breakers." This section of the main differences with GB 14048.2-2001. --- Clearly breaker shall be published impulse withstand voltage Uimp; --- Clear insulating material resistant to abnormal heat and fire requirements. Fixed to the main circuit conductor insulation material 960 ℃; Other Insulation Materials 650 ℃. Inter, but not more than 1h. Breakers should not be moved during this time, in the time trial reset switch on at least every other 1min; --- Higher demands for electromagnetic compatibility. In addition to electronic overcurrent protection circuit breakers, but its auxiliary components, such as. undervoltage release, shunt trip, closing coil, remote Status indicators provides electromagnetic compatibility requirements, specified in Appendix N; --- In the type test, the electromagnetic and electronic trip unit verification discrimination (see 8.3.3.1.2); --- Increase in Appendix L, Appendix M, Appendix N, Appendix O. Appendix L, Appendix M, Appendix O specifies the requirements and test methods for three new products. Appendix L requirements without over-current protection circuit breaker, referred to CBI; Appendix M of Residual Current Devices (Without Internal Current Breaking Device), referred MRCD; Appendix O instantaneous trip circuit breakers, Acronym ICB; Appendix N --- EMC is not included in the additional requirements and test Annex B, Appendix F and Appendix M of the Annex. This section of the Appendix A, Appendix B, Appendix C, Appendix F, Appendix G, Appendix H, Appendix J, Appendix L, Appendix M, N and Appendices Appendix O Normative annex, appendix E and K are informative appendix. This part is proposed by the China Electrical Equipment Industrial Association. The low-voltage electrical part by the National Standardization Technical Committee (SAC/TC189) centralized. This part by the Shanghai Electrical Apparatus Research Institute (Group) Co., Ltd. is responsible for drafting. Participated in the drafting of this section. Changshu Switchgear Manufacturing Co., Ltd., Tianjin Baili Electric Co., Ltd., Shanghai People's electrical plant, Schneider Electric (China) Investment Co., Ltd., Hangzhou, the switch Co., Ltd., Zhejiang Chint Electric Co., Ltd., Suzhou Wanlong Group has Ltd., Delixi Electric Co., Ltd. Shanghai Siemens low-voltage circuit breakers, Tengen Group Co., Limited Huatong Electrical Group The company, Tianshui Electric Co., Ltd. 宁波伊尔特 intelligent electrical switches, electrical switch Ltd. Zhejiang, Shanghai Liang letter Electric Co., General Electric (China) Research and Development Center Co., Ltd., Zhejiang People Electric Co., Ltd., Ningbo Liaoyuan Electric Set Group Co., Ltd. People Electric Group Co., Ltd., Beijing People's electrical plant, Universal Holdings Limited. The main drafters of this section. Wan Shao You, Chen Zhengxin, Gu Huimin, Zhao. The drafters of some of the participants. tube Rui Liang, Liufeng Kun Mou Jian, He Wei Wei, Hu Xuesong, Wang Taiyu, Cheng Yu-standard, Huang Rongrong, Gu Lili, Wangxu Chuan, Feng Xinmin, Wang Xiuhua, Yang Weilong, Shao, Shao Yanqi, Feng Jifeng, Zhao Jianping, Zhu Yin set, Huang Zhang Wu, Nan Yin, Dai Guozhong. This part of the standard replaces the previous editions are. --- GB 14048.2-1994, GB 14048.2-2001. GB 14048.2-2008/IEC 60947-2.2006 Low-voltage switchgear and control equipment Part 2. Circuit Breaker 1 General This section specifically referenced in GB 14048.1-2006 General provisions applicable to this section, any reference in this section of the article quoted General Section, sub-clause, tables, figures and appendices are preceded by GB 14048.1-2006, Example. GB 14048.1-2006 in 1.2.3, GB 14048.1- 2006 or GB 14048.1-2006 Table 4 in Appendix A. 1.1 Scope and purpose This section applies to the main contact for access to rated voltage not exceeding 1000V ac or 1500V dc circuit breaker. this Section also specifies additional requirements of the circuit breaker with fuses. This section applies to any circuit breaker rated current, a variety of structures of various types or intended use. Requirements as a ground breaker protection included in Appendix B. Electronic overcurrent protection circuit breaker Additional requirements included in Appendix F. Additional requirements for the IT system of the circuit breaker is included in Appendix H. Requirements and test methods for electromagnetic compatibility of the circuit breaker is included in Appendix J. No over-current protection circuit breaker requirements included in Appendix L in. Residual Current Devices (Without Internal Current Breaking Device) requirements included in Appendix M of. Requirements and test methods for electromagnetic compatibility of circuit breaker accessories are included in the Appendix N. Instantaneous tripping circuit breaker (ICB) requirements included in Appendix O of. As a direct starter applications breaker 14048.4-2003 Supplementary requirements for low pressure in the contactor and starter GB Provisions. As the building requirements and similar establishments in wire protection, and non-skilled personnel designed for use in the circuit breaker GB 10963 of the regulations. Device (such as an electrical appliance) circuit breaker requirements specified in GB 17701-2008 in. For certain purposes (for example traction, rolling mills and marine) of the circuit breaker, it may make some necessary special provisions and additional requirements. Note. This section refers to the circuit breaker can be equipped with overcurrent and undervoltage except apparatus under predetermined conditions can be automatically disconnected, for example, the reverse current or reverse power off Open devices. This section does not involve such a predetermined condition operation verification. The purpose of this section is to provide. Characteristics of a) the circuit breaker; b) the circuit breaker under the following conditions shall comply with the conditions. 1) actions and performance during normal operation; 2) operation and performance under short-circuit conditions and overload conditions, including operation with the use (such as selectivity and back-up protection Protection cooperation) operation and performance; 3) dielectric properties. c) To prove the tests and test methods used to achieve the above conditions shall be carried out; d) on the circuit breaker marked or given data. 1.2 Normative references The following documents contain provisions which, through reference to "low-voltage switchgear and control equipment" in this section constitute provisions of this section. Every note Dated references, subsequent amendments (excluding corrections) or revisions do not apply to this section, however, encourage root This part of the study, according to the parties to reach an agreement whether the latest versions of these documents. For undated references, the latest edition This applies to this section. GB 14048.2-2008/IEC 60947-2.2006 GB/T 2423.4-2008 Environmental testing for electric and electronic products Part 2. Test methods - Test Db. Damp heat (12h + 12h cycle) (IEC 60068-2-30.2005, IDT) GB/T 2423.22-2002 Environmental testing for electric and electronic products Part 2. Test methods - Test N. Temperature change (idt IEC 60068-2-14. 1984) GB/T 2828.1-2003 Sampling procedures for inspection - Part 1. Press the reception quality (AQL) retrieval batch count sampling inspection Plan (ISO 2859-1.1999, IDT) GB/T 2900.18-2008 Electrotechnical term low-voltage electrical GB 4824-2004 industrial, scientific and medical (ISM) radio-frequency equipment - Electromagnetic disturbance characteristics - Limits and methods of measurement (CISPR 11.2003, IDT) GB/T 5169.10-2006 Fire hazard testing for electric and electronic products - Part 10. Glowing/hot-wire based test methods Glow Wire apparatus and common test procedure (IEC 60695-2-10.2000, IDT) GB/T 5169.11-2006 Fire hazard testing for electric and electronic products - Part 11. Glowing/hot wire based test methods for finished products Glow wire flammability test methods (IEC 60695-2-11.2000, IDT) GB/T 5169.12-2006 Fire hazard testing for electric and electronic products - Part 12. Glowing/hot wire based test methods for materials Glow wire flammability test methods (IEC 60695-2-12.2000, IDT) GB/T 5169.13-2006 Fire hazard testing for electric and electronic products - Part 13. Glowing/hot wire based test methods for materials The glow-wire ignitability test method (IEC 60695-2-13.2000, IDT) GB 6829-1995 General requirements for residual current operated protective devices (eqv IEC 60755.1992) GB/T 7676 (all parts) Direct acting indicating analogue electrical measuring instruments and their accessories GB 10963.1-2005 household and similar circuit breakers for overcurrent protection - Part 1. For AC circuit breaker (IEC 60898-1.2002, IDT) Breakers for ac and dc. GB 10963.2-2003 household and similar circuit breakers for overcurrent protection - Part 2 (IEC 60898-2.2000, IDT) GB 14048.1-2006 Low-voltage switchgear and control equipment Part 1. General (IEC 60947-1.2001, MOD) GB 14048.4-2003 Low-voltage switchgear and control equipment, electromechanical contactors and motor starters (IEC 60947-4-1. 2000, IDT) Electrical installations GB 16895 (all parts) buildings (RCCB) Part 1 GB 16916.1-2003 household and similar uses overcurrent protection for residual current operated circuit breaker Score. General rules (IEC 61008-1.1996, MOD) GB 16917.1-2003 household and similar uses overcurrent protection for residual current operated circuit breaker (RCBO) - Part 1. General rules (IEC 61009-1.1996, MOD) GB 17701-2008 circuit breakers for equipment (IEC 60934.2007, IDT) GB 17625.1-2003 Electromagnetic compatibility - Limits for harmonic current emissions (equipment input current ≤16A) (IEC 61000-3-2.2001, IDT) GB/T 17626.2-2006 Electromagnetic compatibility - Testing and measurement techniques - Electrostatic discharge immunity test (IEC 61000-4-2.2001, IDT) GB/T 17626.3-2006 Electromagnetic compatibility - Testing and measurement techniques RFEMS test (IEC 61000-4-3. 2002, IDT) GB/T 17626.4-2008 Electromagnetic compatibility - Testing and measurement techniques - Electrical fast transient burst immunity test (IEC 61000-4- 4.2004, IDT) GB/T 17626.5-2008 Electromagnetic compatibility - Testing and measurement techniques - Surge (impact) immunity test (IEC 61000-4-5. 2005, IDT) GB/T 17626.6-2008 electromagnetic compatibility (EMC) test and measurement techniques - conducted disturbances, induced RF field immunity (IEC 61000-4-6.2003, IDT) GB 14048.2-2008/IEC 60947-2.2006 GB/T 17626.11-2008 electromagnetic compatibility (EMC) - Testing and measurement techniques - Voltage dips, short interruptions and voltage variations Immunity test (IEC 61000-4-11.2004, IDT) GB/T 17626.13-2006 electromagnetic compatibility test and measurement technology AC power port harmonics and interharmonics including mains signaling Low frequency immunity tests (IEC 61000-4-13.2002, IDT) IEC 60068-2-14. 1984 Environmental testing - Part 2. Test methods - Test N. Change temperature correction member 1 (1986) IEC 60947-1.2004 Low-voltage switchgear and control equipment - Part 1. General IEC 60947-4-1.2000 Low-voltage switchgear and control equipment, electromechanical contactors and motor starters, REV 1 (2002) IEC 61000-3-2.2001 Electromagnetic compatibility (EMC) Limits for harmonic current emissions (equipment input current ≤16A) amended 2 member (2004) IEC 61000-3-3.2000 Electromagnetic compatibility (EMC) limits the rated current is less than 16A power supply system equipment Low voltage wave Fixed and flicker limit correction member 1 (2001) IEC 61000-4-3.2002 Electromagnetic compatibility (EMC) Testing and measurement techniques RFEMS test correction member 1 (2002) IEC /T R61000-5-2.1997 Electromagnetic compatibility (EMC) guidelines for installation and adjustment of grounding and wiring IEC 61008-1.1996 Household and similar uses overcurrent protection for residual current operated circuit breaker (RCCB) - Part 1. General rule, REV 1 (2002) IEC 61009-1.1996 Household and similar uses overcurrent protection for residual current operated circuit breaker (RCBO) - Part 1. General rule, REV 1 (2002) CISPR11.2003 Industrial, scientific and medical (ISM) radio-frequency equipment - Electromagnetic disturbance characteristics - Limits and methods of measurement correction member 1 (2004) CISPR22.2005 Limits and methods of measurement of radio disturbance of information technology equipment, REV 1 (2005) 2 Definitions For most of this section relates to the definition, see Chapter 2 GB 14048.1-2006 and GB/T 2900.18-2008. Of this section, the following additional definitions should be used. 2.1 Can turn, carrying and breaking currents under normal circuit conditions, can also be turned on at specified abnormal circuit (eg short circuit), the bearing Upload a certain time and breaking current of a mechanical switching equipment. 2.1.1 Represents a set of circuit breakers characteristic terminology, structure size of several current ratings are the same frame degree corresponding to the current amount of this group A maximum value, said in a frame degree, the width may vary depending on the number of poles are different. Note. This definition does not include the size standard. 2.1.2 To a significant structural differences exist between the fixed breaker frame sizes, requiring additional type testing (see 7.1.5). 2.2 A combination of a single electrical circuit breakers and fuses made, each phase by a fuse and a circuit breaker pole series. GB 14048.2-2008/IEC 60947-2.2006 2.3 Break time short enough to prevent the short-circuit current reaches its expected peak (otherwise up to this peak) before breaking the circuit breaker. 2.4 In addition to the circuit breaker contacts partakers off, there is a set of separable contacts, so that the circuit breaker can be removed or inserted from the circuit. NOTE. Some breaker only on the supply side of the plug-in and the load terminals is generally in wire. 2.5 In addition to the circuit breaker contacts partakers off, there is a group of the main circuit isolation isolation contacts when in the withdrawn position, you can achieve compliance The required isolation distance breaker. 2.6 Having a housing with an insulating material molded as integral parts of the circuit breaker the circuit breaker. 2.7 Opening and closing the circuit breaker contacts at atmospheric pressure in air. 2.8 The contacts open and close the circuit breaker in a high vacuum tube. 2.9 Opening and closing the circuit breaker contacts in addition to the atmospheric gas or air in the higher pressure outside. 2.10 When closing operation, such as turning the current exceeds a predetermined value, the circuit breaker without any artificial delay opening release, but when the circuit breaker When it does not operate in the closed position. 2.11 For short-circuit protection overcurrent release. 2.12 After a short delay for the operation of overcurrent release. 2.13 Conjoined with the circuit breaker tripping only when the operation of the circuit breaker auxiliary switch. 2.14 When the predetermined condition still exists, even if the closing command is given, each contact can be prevented from closing (ie sufficient energized closed) broken A road. 2.15 Under specified conditions, including electrical switches, including terminal short circuit breaking (or turned on) capabilities. GB 14048.2-2008/IEC 60947-2.2006 2.15.1 Conditions prescribed test procedures prescribed breaker does not require continuous support of its rated current capability of breaking capacity. 2.15.2 Conditions prescribed test procedures prescribed requirements for their continuous support breaker rated current capability of breaking capacity. 2.16 GB 14048.1-2006 applicable in 2.5.39 and added the following. --- For the direct action of the circuit breaker, time off to start is the moment the current increases enough to cause the circuit breaker operation start instantly. --- For the use of any form of auxiliary power supply circuit breaker operation, disconnect the start time instant is off or disconnected applied release Auxiliary instantaneous power. Note. the circuit breaker, the "off-time" is usually referred to as "release time", strictly speaking, tripping time is the moment to start the opening operation off command The time between the moment becomes irreversible. 2.17 Two or more overcurrent protective devices in series, in order to ensure the selective overcurrent protection and/or back-up protection. 2.17.1 Two series of overcurrent protective devices An overcurrent complex. Protection of electrical power supply side (power supply side generally, but not necessarily electrically Electrical source side) in the presence/absence of the other protective devices with the help of over-current protection, and other protective devices to prevent overload. 2.17.2 In the case of an overcurrent protection device in series two, the protective device on the load side when the implementation of the protection without causing the other protective devices Selective overcurrent protection operation. 2.17.3 In the case of an overcurrent protection device in series two, the protective device on the load side at a given value of the overcurrent protection and the implementation of the following When protection without causing the other protective devices selective overcurrent protection. 2.17.4 Is Total time selectivity limit current means the load-side protection device - current characteristics and other protective devices arcing time - current characteristic (Refer fuses) or tripping time - current characteristic (refer to the circuit breaker) current coordinates intersect. Selectivity limit current (see Figure A.1) is a current limit. --- In this value, the overcurrent protection device if the two series, the protective device on the load side completes its breaking operation in time to prevent Stop on a protection device starts to operate (ie, to ensure that the selectivity); --- More than this value, the overcurrent protection device if the two series, the protective device on the load side may not complete its breaking operation in time But not on a protective device to prevent its start operation (ie selectivity is not guaranteed). 2.17.5 GB 14048.1-2006 in 2.5.24 apply. GB 14048.2-2008/IEC 60947-2.2006 2.17.6 IB GB 14048.1-2006 applicable in 2.5.25 and added the following. Purpose of this part, GB 14048.1-2006 2.5.25 apply to the off-time ≥0.05s two series overcurrent protection Means. For off time < overcurrent device 0.05s two series can be considered as complex, see Appendix A. Note. The transfer means the current maximum breaking time overcurrent protective devices in series between two sets - current characteristic intersects the current coordinates. 2.18 To the maximum current can be expected, the largest prospective current corresponding to the rated short-circuit breaking capacity and associated voltage current expectations. 2.19 After a circuit breaker overcurrent trip back to its reach through time between a closed condition. 2.20 So release without any artificial delay action current rating. Category 3 3.1 Use by category. --- A category (see 4.4); --- Class B (see 4.4). 3.2 points by breaking media, such as. --- Carve off the air; --- Vacuum carve off; --- Gas carve off. 3.3 design by sub-type, for example. --- Universal; --- Molded case. 3.4 Press control method of operating mechanism of points, namely. --- Related to human operations; --- Independent manual operation; --- Dependent power operation; --- Unrelated power operation; --- Charging operation. 3.5 points according to the suitability of Isolation. --- Suitable for isolation; --- Not for isolation. Whether in need of repair by 3.6 points. --- In need of repair; --- No maintenance. GB 14048.2-2008/IEC 60947-2.2006 3.7 points according to the installation, such as. --- Fixed; --- Plug-in; --- Drawer. 3.8 Press shell protection rating (see GB 14048.1-2006 in 7.1.11). 4 Characteristics of circuit breakers 4.1 Features Overview Characteristics of the circuit breaker must (if applicable) indicate the follow...... ...