Standard No.:	GB 3906-2006
English Name:	Alternating-current metal-enclosed switchgear and controlgear for rated voltages above 3.6 kV and up to and including 40.5 kV
Chinese Name:	3.6kV～40.5kV交流金属封闭开关设备和控制设备
Chinese Classification:	K43    High voltage switchgear
Professional Classification:	GB    National Standard
ICS Classification:	29.240.10 29.240.10    Substations. Surge arresters 29.240.10
Issued by:	AQSIQ and SAC
Issued on:	2006-8-25
Implemented on:	2007-3-1
Status:	valid
Superseding:	GB 3906-1991 A.C.metal-enclosed switchgear for rated voltages of 3~35kV
Language:	English
File Format:	PDF
Word Count:	33000 words
Price(USD):	820.0
Delivery:	via email in 1 business day

1 General 1.1 Scope This standard specifies requirements for factory-assembled metal-enclosed switchgear and controlgear for alternating current of rated voltages of 3.6kV~40.5kV for indoor and outdoor installation, and for service frequencies up to and including 50 Hz. Enclosures may include fixed and removable components and may be filled with fluid (liquid or gas) to provide insulation. NOTE 1 Although primarily dedicated to three-phase systems, this standard can also be applied to single-phase or two-phase systems. This standard defines several types of metal enclosed switchgear and controlgear which differ due to ——the consequences on network service continuity in case of maintenance on the switchgear and controlgear; ——the need and convenience of maintenance of the equipment. NOTE 2 Safety of an installation results from the design, implementation and coordination of products, installations and operations. For metal-enclosed switchgear and controlgear containing gas-filled compartments, the design pressure is limited to a maximum of 0.3MPa (relative pressure). NOTE 3 Gas-filled compartments having a design pressure exceeding 0.3MPa (relative pressure) should be designed and tested in accordance with GB 7674. Metal-enclosed switchgear and controlgear for special use, for example, in flammable atmospheres, in mines or on board ships, may be subject to additional requirements. Components contained in metal-enclosed switchgear and controlgear are to be designed and tested in accordance with their various relevant standards. This standard supplements the standards for the individual components regarding their installation in switchgear and controlgear assemblies. This standard does not preclude that other equipment may be included in the same enclosure. In such a case, any possible influence of that equipment on the switchgear and controlgear is to be taken into account. NOTE 4 Switchgear and controlgear assemblies having an insulation enclosure are covered by IEC 60466: 1987. NOTE 5 Metal-enclosed switchgear and controlgear for rated voltages above 40.5kV insulated by ambient air may be covered by this standard taking into account the insulation levels of GB/T 11022-1999. 1.2 Normative References The following normative documents contain provisions which, through reference in this standard, constitute provisions of this standard. For dated reference, subsequent amendments (excluding amending errors) to, or revisions of, any of these publications do not apply. However, all parties coming to an agreement according to this standard are encouraged to study whether the latest editions of these documents are applicable. For undated references, the latest edition of the normative document referred to applies. GB/T 1408.1-1999 Methods of test for electric strength of solid insulating materials-tests at power frequencies (eqv IEC 60243-1: 1988) GB 1984-2003 High-voltage alternating-current circuit-breakers (IEC 62271-100: 2001 MOD) GB 1985-2004 High-voltage alternating-current disconnectors and earthing switches (IEC 62271-102: 2002 MOD) GB/T 2423.17-1993 Basic environmental testing procedures for electric and electronic products Part 17 - Test Ka: Salt mist (eqv IEC 60068-2-11: 1981) GB/T 2900.20-1994 Electrotechnical terminology-High-voltage switchgear (neq IEC 60050 (441), IEC 60056 etc.) GB 3804-2004 High-voltage alternating-current switches for rated voltage above 3.6 kV and less than 40.5 kV (IEC 60265-1: 1998 MOD) GB 4208-1993 Degrees of protection provided by enclosure (IP code) (eqv IEC 60529: 1989) GB/T 7354-2003 Partial discharge measurements (IEC 60270: 2000 IDT) GB/T 8905-1996 The guide for processing and measuring SF6 gas in power apparatus (neq IEC 60480: 1974) GB/T 11022-1999 Common specifications for high-voltage switchgear and controlgear standards (eqv IEC 60694: 1996) GB/T 14808-2001 High-voltage alternating current contactors and contactor-based motor-starters (eqv IEC 60470: 1999) GB 16926-1997 High-voltage alternating current switch-fuse combinations (eqv IEC 60420: 1990) GB/T 16927.1-1997 Hign voltage test techniques-Part 1: General test requirements (eqv IEC 60060-1: 1989) IEC 60466:1987 AC insulation-enclosed switchgear and controlgear for rated voltages above 1kv and up to and including 38kv IEC 60694: 2002 Common specifications for high-voltage switchgear and controlgear standards IEC 60909-0: 2001 Short-circuit currents in three-phase ac systems-Part 0: Calculation of currents IEC 61634:1995 High-voltage switchgear and controlgear-Use and handling of sulphur hexafluoride (SF6) in high-voltage switchgear and controlgear ISO/IEC Guide 51:1999, Safety aspects – Guidelines for their inclusion in standards 2 Normal and Special Service Conditions Chapter 2 of GB/T 11022-1999 is applicable with the following addition: Unless otherwise specified in this standard, the metal-enclosed switchgear and controlgear is designed to be used under normal service conditions. 3 Terms and Definitions For the purposes of this document, the following definitions as well as the definitions of GB/T 2900.20-1994 and GB/T 11022-1999 apply. 3.101 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 equipment with associated interconnections, accessories, enclosures and supporting structures 3.102 metal-enclosed switchgear and controlgear Switchgear and controlgear assemblies with an external metal enclosure intended to be earthed and completely assembled, except for external connections 3.103 functional unit (of an assembly) Part of metal-enclosed switchgear and controlgear comprising all the components of the main circuits and auxiliary circuits that contribute to the fulfilment of a single function NOTE Functional units may be distinguished according to the function for which they are intended, for example, incoming unit, outgoing unit, etc. 3.104 multi-tier Two or more functional units arranged vertically within a single enclosure 3.105 transport unit Part of metal-enclosed switchgear and controlgear suitable for shipment without being dismantled 3.106 enclosure Part of metal-enclosed switchgear and controlgear providing a specified degree of protection of equipment against external influences and a specified degree of protection against approach to or contact with live parts and against contact with moving parts 3.107 compartment Part of metal-enclosed switchgear and controlgear enclosed except for openings necessary for interconnection, control or ventilation Four types of compartments are distinguished, three that can be opened, called accessible (see 3.107.1 to 3.107.3) and one that cannot be opened, called non-accessible (see 3.107.4) NOTE Compartments are identified according to the main component(s) contained therein, see 5.103.1. 3.107.1 interlock-controlled accessible compartment Compartment containing high-voltage parts, intended to be opened for normal operation and/or normal maintenance as stated by the manufacturer, in which access is controlled by integral design of the switchgear and controlgear NOTE Installation, extension, repairing, etc. are not considered as normal maintenance. 3.107.2 procedure-based accessible compartment Compartment containing high-voltage parts, intended to be opened for normal operation and/or normal maintenance as stated by the manufacturer, in which access is controlled by a suitable procedure combined with locking NOTE Installation, extension, repairing, etc. are not considered as normal maintenance. 3.107.3 tool-based accessible compartment Compartment containing high-voltage parts, that may be opened, but not for normal operation and maintenance. Special procedures are required. Tools are necessary for opening 3.107.4 unaccessible compartment Compartment containing high-voltage parts that must not be opened. Opening may destroy the integrity of the compartment. Clear indication not to open is provided on/by the compartment

Content Foreword i 1 General 1.1 Scope 1.2 Normative References 2 Normal and Special Service Conditions 3 Terms and Definitions 4 Ratings 4.1 Rated Voltage (Ur) 4.2 Rated Insulation Level 4.3 Rated Frequency (fr) 4.4 Rated Normal Current and Temperature Rise 4.5 Rated Short-time Withstand Current (Ik) 4.6 Rated Peak Withstand Current (Ip) 4.7 Rated Duration of Short Circuit (tk) 4.8 Rated Supply Voltage of Closing and Opening Devices and of Auxiliary and Control 4.9 Rated Supply Frequency of Closing and Opening Devices and of Auxiliary Circuits 4.10 Rated Pressure of Compressed Gas Supply for Insulation and/or Operation 5 Design and Construction 5.1 Requirements for Liquidsin Switchgear and Controlgear 5.2 Requirements for Gases in Switchgear and Controlgear 5.3 Earthing 5.4 Auxiliary and Control Equipment 5.5 Dependent Power Operation 5.6 Stored Energy Operation 5.7 Independent Manual Operation 5.8 Operation of Releases 5.9 Low- and High-pressure Interlocking and Monitoring Devices 5.10 Nameplates 5.11 Interlocking Devices 5.12 Position Indication 5.13 Degrees of Protection by Enclosures 5.14 Creepage Distances 5.15 Gas and Vacuum Tightness 5.16 Liquid Tightness 5.17 Flammability 5.18 Electromagnetic Compatibility (EMC) 5.101 Internal Fault 5.102 Enclosure 5.103 Compartments 5.104 Removable Parts 5.105 Provisions for Dielectric Tests on Cables 5.106 Anti-corrosion Requirements 6 Type Tests 6.1 General 6.2 Dielectric Tests 6.3 Radio Interference Voltage (r.i.v.) Test 6.4 Measurement of the Resistance of Circuits 6.5 Temperature-rise Test 6.6 Short-time Withstand Current and Peak Withstand Current Tests 6.7 Verification of the Protection 6.8 Tightness Tests 6.9 Electromagnetic Compatibility Tests (EMC) 6.10 Additional Tests on Auxiliary and Control Circuits 6.101 Verification of Making and Breaking Capacities 6.102 Mechanical Operation and Properties Measurement Tests 6.103 Pressure Withstand Test for Gas-Filled Compartments 6.104 Tests on Non-metallic Partitions and Shutters 6.105 Weatherproofing Test 6.106 Internal Arcing Test 6.107 Corrosion Withstand Test 7 Routine Tests 7.1 Dielectric Test on the Main Circuit 7.2 Tests on Auxiliary and Control Circuits 7.3 Measurement of the Resistance of the Main Circuit 7.4 Tightness Test 7.5 Design and Visual Checks 7.101 Partial Discharge Measurement 7.102 Mechanical Operation and Properties Measurement Tests 7.104 Tests of Auxiliary Electrical, Pneumatic and Hydraulic Devices 7.105 Tests after Erection On Site 7.106 Measurement Of Fluid Condition after Filling on Site 8 Guide to the Selection of Metal-enclosed Switchgear and Controlgear for Service 8.1 Selection of Rated Values 8.2 Selection of Design and Construction 8.3 Internal Arc Classification 9 Information to be Given with Enquiries, Tenders and Orders 9.101 Information with Enquiries and Orders 9.102 Information with Tenders 10 Rules for Transport, Storage, Installation, Operation and Maintenance 10.1 Conditions during Transport, Storage and Installation 10.2 Installation 10.3 Operation 10.4 Maintenance 11 Safety 11.101 Procedures 11.102 Internal Arc Aspects Annex A (Normative) Internal Fault -- Method for Testing the Metal-enclosed Switchgear and Controlgear under Conditions of Arcing Due to an Internal Fault Annex B (Normative) Partial discharge measurement Annex C (Normative) Additional Requirements Used for 3.6kv~40.5kv AC Metal-Enclosed Switchgear and Controlgear Under Stern Climate Condition Annex D (Normative) Calculation Method of Cross Sectional Area of Bare Conductor in accordance with Thermal Effect of Short-Time Persistent Current Annex E (Informative) Explanatory Notes Bibliography

*GB/T 1408.1-1999 Methods of test for electric strength of solid insulating materials―Tests at power frequencies
*GB 1984-2003 High-voltage alternating-current circuit-breakers
*GB 1985-2004 High-voltage Alternating-current Disconnectors and Earthing Switche
*GB/T 2423.17-1993 Basic environmental testing procedures for electric and electronic products Test Ka:Salt mist
*GB/T 2900.20-1994 Electrotechnical terminology High-voltage switchgear
*GB 3804-2004 High-voltage alternating-current switches for rated voltage above 3.6 kV and less than 40.5 kV
*GB 4208-1993 Degrees of protection provided by enclosure (IP code)
*GB/T 7354-2003 Partial discharge measurements
*GB/T 8905-1996 The guide for processing and measuring SF6 Gas in power apparatus
*GB/T 11022-1999 Common specifications for high-voltage switchgear and controlgear standards
*GB/T 14808-2001 High-voltage alternating current contactors and contactor-based motor-starters
*GB 16926-1997 High-voltage alternating current switch-fuse combinations
*GB/T 16927.1-1997 Hign voltsge test techniques - Part 1: General test requirements