CONTENTS
CONTENTS 2
FOREWORD 7
INTRODUCTION 10
1Scope 11
2Normative references 12
3Terms and definitions 15
3.1General definitions 15
3.2Definitions concerning installations 17
3.3Definitions concerning types of installations 17
3.4Definitions concerning safety measures against electric shock 18
3.5Definitions concerning clearances 18
3.6Definitions concerning control and protection 19
3.7Definitions concerning earthing 20
4Fundamental requirements 24
4.1General 24
4.1.1General requirements 24
4.1.2Agreements between supplier (manufacturer) and user 24
4.2Electrical requirements 25
4.2.1Methods of neutral earthing 25
4.2.2Voltage classification 26
4.2.3Current in normal operation 26
4.2.4Short-circuit current 26
4.2.5Rated frequency 27
4.2.6Corona 27
4.2.7Electric and magnetic fields 27
4.2.8Overvoltages 27
4.2.9Harmonics 27
4.3Mechanical requirements 27
4.3.1Equipment and supporting structures 27
4.3.2Tension load 28
4.3.3Erection load 28
4.3.4Ice load 28
4.3.5Wind load 28
4.3.6Switching forces 28
4.3.7Short-circuit forces 29
4.3.8Loss of conductor tension 29
4.3.9Vibration Seismic loads 29
4.3.10Dimensioning of supporting structures 29
4.4Climatic and environmental conditions 29
4.4.1General 29
4.4.2Normal conditions 30
4.4.3Special conditions 31
4.5Special requirements 32
4.5.1Effects of small animals and micro-organisms 32
4.5.2Noise level 33
4.5.3Transport 33
5Insulation 33
5.1General 33
5.2Selection of insulation level 33
5.2.1Consideration of methods of neutral earthing 33
5.2.2Consideration of rated withstand voltages 33
5.3Verification of withstand values 33
5.4Minimum clearances of live parts 34
5.4.1General 34
5.4.2Minimum clearances in voltage range I 34
5.4.3Minimum clearances in voltage range II 34
5.5Minimum clearances between parts under special conditions 37
5.6Tested connection zones 37
6Equipment 37
6.1General requirements 37
6.1.1Selection 37
6.1.2Compliance 37
6.1.3Personnel safety 37
6.2Specific requirements 38
6.2.1Switching devices 38
6.2.2Power transformers and reactors 38
6.2.3Prefabricated type-tested switchgear 39
6.2.4Instrument transformers 39
6.2.5Surge arresters 40
6.2.6Capacitors 40
6.2.7Line traps 40
6.2.8Insulators 40
6.2.9Insulated cables 41
6.2.10Conductors and accessories 43
6.2.11Rotating electrical machines 43
6.2.12Generating units 44
6.2.13Generating unit main connections 44
6.2.14Static converters 45
6.2.15Fuses 45
6.2.16Electrical and mechanical Interlocking 45
7Installations 46
7.1General requirements 46
7.1.1Circuit arrangement 46
7.1.2Documentation 47
7.1.3Transport routes 47
7.1.4Aisles and access areas 47
7.1.5Lighting 47
7.1.6Operational safety 48
7.1.7Labelling 48
7.2Outdoor installations of open design 48
7.2.1Protective barrier clearances 48
7.2.2Protective obstacle clearances 49
7.2.3Boundary clearances 49
7.2.4Minimum height over access area 49
7.2.5Clearances to buildings 49
7.2.6External fences or walls and access doors 50
7.3Indoor installations of open design 50
7.4Installation of prefabricated type-tested switchgear 50
7.4.1General 50
7.4.2Additional requirements for gas-insulated metal-enclosed switchgear 51
7.5Requirements for buildings 52
7.5.1Introduction 52
7.5.2Structural provisions 52
7.5.3Rooms for switchgear 53
7.5.4Maintenance and operating areas 54
7.5.5Doors 54
7.5.6Draining of insulating liquids 55
7.5.7Air conditioning and ventilation 55
7.5.8Buildings which require special consideration 55
7.6High voltage/low voltage prefabricated substations 55
7.7Electrical installations on mast, pole and tower 56
8Safety measures 63
8.1General 63
8.2Protection against direct contact 63
8.2.1Measures for protection against direct contact 63
8.2.2Protection requirements 64
8.3Means to protect persons in case of indirect contact 65
8.4Means to protect persons working on electrical installations 65
8.4.1Equipment for isolating installations or apparatus 65
8.4.2Devices to prevent reclosing of isolating devices 66
8.4.3Devices for determining the de-energized state 66
8.4.4Devices for earthing and short-circuiting 66
8.4.5Equipment acting as protective barriers against adjacent live parts 67
8.4.6Storage of personal protection equipment 68
8.5Protection from danger resulting from arc fault 68
8.6Protection against direct lightning strokes 68
8.7Protection against fire 69
8.7.1General 69
8.7.2Transformers, reactors 69
8.7.3Cables 73
8.7.4Other equipment with flammable liquid 73
8.8Protection against leakage of insulating liquid and SF6 73
8.8.1Insulating liquid leakage and subsoil water protection 73
8.8.2SF6 leakage 75
8.8.3Failure with loss of SF6 and its decomposition products 75
8.9Identification and marking 75
8.9.1General 75
8.9.2Information plates and warning plates 76
8.9.3Electrical hazard warning 76
8.9.4Installations with incorporated capacitors 76
8.9.5Emergency signs for emergency exits 76
8.9.6Cable identification marks 76
9Protection, control and auxiliary systems 83
9.1Monitoring and control systems 83
9.2DC and AC supply circuits 84
9.2.1General 84
9.2.2AC supply 84
9.2.3DC supply 85
9.3Compressed air systems 85
9.4SF6 gas handling plants 86
9.5Hydrogen handling plants 86
9.6Basic rules for electromagnetic compatibility of control systems 87
9.6.1General 87
9.6.2Electrical noise sources in high voltage installations 87
9.6.3Measures to be taken to reduce the effects of high frequency
interference 87
9.6.4Measures to be taken to reduce the effects of low frequency
interference 88
9.6.5Measures related to the selection of equipment 88
9.6.6Other possible measures to reduce the effects of interference 89
10Earthing systems 89
10.1General 89
10.2Fundamental requirements 89
10.2.1Safety criteria 89
10.2.2Functional requirements 90
10.2.3High and low voltage earthing systems 90
10.3Design of earthing systems 91
10.3.1General 91
10.3.2Power system faults 92
10.3.3Lightning and transients 92
10.4Construction of earthing systems 93
10.5Measurements 93
10.6Maintainability 93
10.6.1Inspections 93
10.6.2Measurements 93
11Inspection and testing 94
11.1General 94
11.2Verification of specified performances 95
11.3Tests during installation and commissioning 95
11.4Trial running 95
12Operation and maintenance manual 96
Annex A (normative) Values of rated insulation levels and minimum clearances based
on current practice in some countries 97
Annex B (normative) Method of calculating permissible touch voltages 100
Annex C (normative) Permissible touch voltage according IEEE 80 101
Annex D (normative) Earthing system design flow chart 102
Annex E (informative) Protection measures against direct lightning strokes 104
Bibliography 108
Figure 1 – Protection against direct contact by protective barriers/protective obstacles
within closed electrical operating areas 57
Figure 2 – Boundary distances and minimum height at the external fence/wall 59
Figure 3 – Minimum heights and working clearances within closed electrical operating
areas 60
Figure 4 – Approaches with buildings (within closed electrical operating areas) 61
Figure 5 – Minimum approach distance for transport 62
Figure 6 – Separating walls between transformers 77
Figure 7 – Fire protection between transformer and building 80
Figure 8 – Sump with integrated catchment tank 81
Figure 9 – Sump with separate catchment tank 81
Figure 10 – Sump with integrated common catchment tank 82
Figure 11 – Example for small transformers without gravel layer and catchment tank 82
Figure 12 – Permissible touch voltage UTp 94
Figure C.1 – Permissible touch voltage UTp according IEEE 80 101
Figure E.1 – Single shield wire 105
Figure E.2 – Two shield wires 105
Figure E.3 – Single lightning rod 106
Figure E.4 – Two lightning rods 107
Table 1 – Minimum clearances in air – Voltage range I (1 kV Um 245 kV) 35
Table 2 – Minimum clearances in air – Voltage range II (Um 245 kV) 36
Table 3 – Guide values for outdoor transformer clearances 71
Table 4 – Minimum requirements for the installation of indoor transformers 72
Table 5 – Minimum requirements for interconnection of low-voltage and high-voltage
earthing systems based on EPR limits 91
Table A.1 – Values of rated insulation levels and minimum clearances in air for 1 kV
Um 245 kV for highest voltage for installation Um not standardized by the IEC based
on current practice in some countries 97
Table A.2 – Values of rated insulation levels and minimum clearances in air for 1 kV
Um 245 kV for highest voltage for installation Um not standardized by IEC based on
current practice in some countries 98
Table A.3 – Values of rated insulation levels and minimum clearances in air for Um > 245 kV for highest voltages for installation Um not standardized by IEC based on
current practice in some countries 99
POWER INSTALLATIONS EXCEEDING 1 kV AC –
Part 1: Common rules
1 Scope
This part of IEC 61936 provides common rules for the design and the erection of electrical power installations in systems with nominal voltages above 1 kV a.c. and nominal frequency up to and including 60 Hz, so as to provide safety and proper functioning for the use intended.
For the purpose of interpreting this standard, an electrical power installation is considered to be one of the following:
a)Substation, including substation for railway power supply
b)Electrical installations on mast, pole and tower
Switchgear and/or transformers located outside a closed electrical operating area
c)One (or more) power station(s) located on a single site
The installation includes generators and transformers with all associated switchgear and all electrical auxiliary systems. Connections between generating stations located on different sites are excluded.
d)The electrical system of a factory, industrial plant or other industrial, agricultural, commercial or public premises
e)Electrical installations erected on offshore platforms e.g. offshore wind power farms. The electrical power installation includes, among others, the following equipment:
–rotating electrical machines;
–switchgear;
–transformers and reactors;
–converters;
–cables;
–wiring systems;
–batteries;
–capacitors;
–earthing systems;
–buildings and fences which are part of a closed electrical operating area;
–associated protection, control and auxiliary systems;
– large air core reactor.
NOTE In general, a standard for an item of equipment takes precedence over this standard.
This standard does not apply to the design and erection of any of the following:
–overhead and underground lines between separate installations;
–electric railways;
–mining equipment and installations;
–fluorescent lamp installations;
–installations on ships according to IEC 60092 [34] series and offshore installations; units according to IEC 61892 [35] series, which are used in the offshore petroleum industry for drilling, processing and storage purposes.
–electrostatic equipment (e.g. electrostatic precipitators, spray-painting units);
–test sites;
–medical equipment, e.g. medical X-ray equipment.
This standard does not apply to the design of factory-built prefabricated, type-tested switchgear and high voltage/low voltage prefabricated substation, for which separate IEC standards exist.
This standard does not apply to the requirements for carrying out live working on electrical installations.
If not otherwise required in this standard, for low-voltage electrical installations the standard series IEC 60364 applies.
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 60034-1, Rotating electrical machines – Part 1: Rating and performance
IEC 60034-3, Rotating electrical machines – Part 3: Specific requirements for synchronous generators driven by steam turbines or combustion gas turbines
IEC 60060-1, High-voltage test techniques – Part 1: General definitions and test requirements
IEC 60071-1, Insulation co-ordination – Part 1: Definitions, principles and rules
IEC 60071-2:1996, Insulation co-ordination – Part 2: Application guide
IEC 60076-2:1993, Power transformers – Part 2: Temperature rise
IEC 60076-11, Power transformers – Part 11: Dry-type transformers
IEC 60079-0, Explosive atmospheres – Part 0: Equipment – General requirements
IEC 60079-10-1, Explosive atmospheres – Part 10-1: Classification of areas – Explosive gas atmospheres
IEC 60079-10-2, Explosives atmospheres – Part 10-2: Classification of areas – Combustible dust atmospheres
IEC 60255 (all parts), Measuring relays and protection equipment
IEC 60331-21, Tests for electric cables under fire conditions – Circuit integrity – Part 21: Procedures and requirements – Cables of rated voltage up to and including 0,6/1,0 kV
IEC 60331-1, Tests for electric cables under fire conditions – Circuit integrity – Part 1: Test method for fire with shock at a temperature of at least 830 °C for cables of rated voltage up to and including 0,6/1,0 kV and with an overall diameter exceeding 20 mm
IEC 60332 (all parts), Tests on electric and optical fibre cables under fire conditions
IEC 60364 (all parts), Low-voltage electrical installations
IEC/TS 60479-1:2005, Effects of current on human beings and livestock – Part 1: General aspects
IEC 60529, Degrees of protection provided by enclosures (IP Code)
IEC 60617, Graphical symbols for diagrams
IEC 60721-2-6, Classification of environmental conditions – Part 2-6: Environmental conditions appearing in nature – Earthquake vibration and shock
IEC 60721-2-7, Classification of environmental conditions – Part 2-7: Environmental conditions appearing in nature. Fauna and flora
IEC 60754-1, Test on gases evolved during combustion of materials from cables – Part 1: Determination of the amount of halogen acid gas
IEC 60754-2, Test on gases evolved during combustion of electric cables – Part 2: Determination of degree of acidity of gases evolved during the combustion of materials taken from electric cables by measuring pH and conductivity
IEC/TS 60815-1, Selection and dimensioning of high-voltage insulators intended for use in polluted conditions – Part 1: Definitions, information and general principles
IEC 60826, Design criteria of overhead transmission lines
IEC 60865-1, Short-circuit currents – Calculation of effects – Part 1: Definitions and calculation methods
IEC 60909 (all parts), Short-circuit currents in three-phase a.c. systems
IEC 60949, Calculation of thermally permissible short-circuit currents, taking into account non- adiabatic heating effects
IEC/TR 61000-5-2, Electromagnetic compatibility (EMC) – Part 5: Installation and mitigation guidelines – Section 2: Earthing and cabling
IEC 61034-1, Measurement of smoke density of cables burning under defined conditions – Part 1: Test apparatus
IEC 61082-1, Preparation of documents used in electrotechnology – Part 1: Rules
IEC 61100, Classification of insulating liquids according of fire-point and net calorific value
IEC 61140, Protection against electric shock – Common aspects for installation and equipment
IEC 61219, Live working – Earthing or earthing and short-circuiting equipment using lances as a short-circuiting device – Lance earthing
IEC 61230, Live working – Portable equipment for earthing or earthing and short-circuiting
IEC 61243 (all parts), Live working – Voltage detectors
IEC/TS 61463, Bushings – Seismic qualification
IEC 62271-1:2007, High-voltage switchgear and controlgear – Part 1: Common specifications
Amendment 1:2011
IEC 62271-200, High-voltage switchgear and controlgear – Part 200: AC metal-enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV
IEC 62271-201, High-voltage switchgear and controlgear – Part 201: AC insulation-enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV
IEC 62271-202, High-voltage switchgear and controlgear – Part 202: High-voltage/low-voltage prefabricated substation
IEC 62271-203, High-voltage switchgear and controlgear – Part 203: Gas-insulated metal- enclosed switchgear for rated voltages above 52 kV
IEC 62271-206, High-voltage switchgear and controlgear – Part 206: Voltage presence indicating systems for rated voltages above 1 kV and up to and including 52 kV
IEC 62271-207, High-voltage switchgear and controlgear – Part 207: Seismic qualification for gas-insulated switchgear assemblies for rated voltages above 52 kV
IEC/TR 62271-300, High-voltage switchgear and controlgear – Part 300: Seismic qualification of alternating current circuit-breakers
IEC/TR 62271-303, High-voltage switchgear and controlgear – Part 303: Use and handling of sulphur hexafluoride (SF6)
IEC 62305 (all parts), Protection against lightning
IEC 62305-4, Protection against lightning – Part 4: Electrical and electronic systems within structures
IEC 82079-1, Preparation of instructions for use – Structuring, content and presentation – Part 1: General principles and detailed requirements
IEC Guide 107, Electromagnetic compatibility – Guide to the drafting of electromagnetic compatibility publications
ISO/IEC Guide 51, Safety aspects – Guidelines for their inclusion in standards
ISO 1996-1, Acoustics – Description, measurement and assessment of environmental noise – Part 1: Basic quantities and assessment-procedures
IEEE 80, Guide for safety in AC substation grounding
IEEE 980, Guide for containment and control of oil spills in substations
Official Journal of the European Communities, No. C 62/23 dated 28.2.1994: Interpretative document, Essential requirements No. 2, “safety in case of fire”
Bibliography
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2 CISPR 18-2, Radio interference characteristics of overhead power lines and high-voltage equipment – Part 2: Methods of measurement and procedure of determining limits
3 CISPR 18-3, Radio interference characteristics of overhead power lines and high-voltage equipment – Part 3: Code of practice for minimizing the generation of radio noise
[4]IEC 60038, IEC standard voltages
[5]IEC 60044-6, Instrument transformers – Part 6: Requirements for protective current transformers for transient performance
[6]IEC 60050-151, International Electrotechnical Vocabulary – Part 151: Electrical and magnetic devices
[7]IEC 60050-195, International Electrotechnical Vocabulary – Part 195: Earthing and protection against electric shock
[8]]IEC 60050-411, International Electrotechnical Vocabulary – Chapter 411: Rotating machines
[9]IEC 60050-441, International Electrotechnical Vocabulary – Chapter 441: Switchgear, controlgear and fuses
[10]IEC 60050-601, International Electrotechnical Vocabulary – Chapter 601: Generation, transmission and distribution of electricity – General
[11]IEC 60050-602, International Electrotechnical Vocabulary – Part 602: Generation, transmission and distribution of electricity – Generation
[12]IEC 60050-604, International Electrotechnical Vocabulary – Chapter 604: Generation, transmission and distribution of electricity – Operation
[13]IEC 60050-605, International Electrotechnical Vocabulary – Chapter 605: Generation, transmission and distribution of electricity – Substations
[14]IEC 60050-651, International Electrotechnical Vocabulary – Part 651: Live working
[15]IEC 60050-826, International Electrotechnical Vocabulary – Part 826: Electrical installations
[16]IEC 60068 (all parts), Environmental testing
17 IEC 60364-4-41, Low-voltage electrical installations – Part 4-41: Protection for safety –
Protection against electric shock
[18]IEC 60480, Guidelines for the checking and treatment of sulphur hexafluoride (SF6) taken from electrical equipment and specification for its re-use
[19]IEC 60664-1, Insulation co ordination for equipment within low-voltage systems – Part 1: Principles, requirements and tests
[20]IEC 60721-2-2, Classification of environmental conditions – Part 2-2: Environmental conditions appearing in nature – Precipitation and wind
[21]IEC 60721-2-3, Classification of environmental conditions – Part 2-3: Environmental conditions appearing in nature – Air pressure
[22]IEC 60721-2-4, Classification of environmental conditions – Part 2-4: Environmental conditions appearing in nature – Solar radiation and temperature
[23]IEC 62271-100, High voltage switchgear and controlgear – Part 100: High-voltage alternating current circuit-breakers
[24]IEC 62271-102, High voltage switchgear and controlgear – Part 102: High-voltage alternating current disconnectors and earthing switches
[25]IEC 62271-103, High voltage switchgear and controlgear – Part 103: Switches for rated voltages above 1 kV and less than 52 kV
[26]IEC 62271-104, High voltage switchgear and controlgear – Part 104: Switches for rated voltages of 52 kV and above
[27]IEC 62271-105, High voltage switchgear and controlgear – Part 105: Alternating current switch-fuse combinations
28 IEEE Guide 998:1996, IEEE Guide for Direct Lightning Stroke Shielding of Substations
29 CIGRE Report 23-04:1972, Handling of SF6 and its decomposition products in gas insulated switchgear
30 CIGRE Report 23-07:1991, Adaptation of substations to their environment both in urban and rural areas, including noise problems and oil pollution of subsoil
31 CIGRE Guide No. 234: August 2003, SF6 Recycling Guide (Revision 2003)
32] CIGRE Guide No. 276: August 2005, Guide for the preparation of customized 'Practical SF6 Handling Instructions'
33 Factory Mutual Global Standard 3990, 06/1997: Approval standard for Less or Nonflammable Liquid Insulated Transformers
[34]IEC 60092 (all parts), Electrical installations in ships
[35]IEC 61892 (all parts), Mobile and fixed offshore units – Electrical installations
[36]EN 13501-1, Fire classification of construction products and building elements – Part 1: Classification using data from reaction to fire tests
[37]EN 13501-2, Fire classification of construction products and building elements – Part 2: Classification using data from fire resistance tests, excluding ventilation services