CONTENTS
FOREWORD 8
INTRODUCTION 10
1General 11
1.1Scope 11
1.2Normative references 11
2Normal and special service conditions 13
2.1Normal service conditions 13
2.1.1Indoor switchgear and controlgear 13
2.1.1.101Low-voltage switchgear and controlgear 13
2.1.1.102Transformer 13
2.1.2Outdoor switchgear and controlgear 14
2.2Special service conditions 14
2.2.1Altitude 14
2.2.2Pollution 14
2.2.3Temperature and humidity 15
2.2.4Vibrations, shock or tilting 15
2.2.5Wind speed 15
2.2.6Other parameters 15
3Terms and definitions 15
4Ratings 17
4.1Rated voltage (Ur) 18
4.2Rated insulation level 18
4.3Rated frequency (fr) 19
4.4Rated normal current and temperature rise 19
4.4.1Rated normal current (Ir) 19
4.4.2Temperature rise 19
4.4.3Particular points of Table 3 19
4.5Rated short-time withstand current (Ik) 19
4.5.101Rated short-time withstand current of high voltage switchgear
and controlgear and high voltage interconnection (Ik) 20
4.5.102Rated short-time phase to earth withstand current (Ike) 20
4.5.103Rated short-time withstand currents of low voltage switchgear
and controlgear and low voltage interconnection (Icw) 20
4.6Rated peak withstand current (Ip) 20
4.6.101Rated peak withstand current (Ip) 20
4.6.102Rated peak phase to earth withstand current (Ipe) 20
4.6.103Rated peak withstand currents of low voltage switchgear and
controlgear and low voltage interconnection (Ipk) 20
4.7Rated durations of short circuit (tk) 20
4.7.101Rated duration of short circuit (tk) 21
4.7.102Rated duration of phase to earth short circuit (tke) 21
4.7.103Rated duration of short circuits for low voltage switchgear and
controlgear and low voltage interconnection 21
4.7.104Rated duration of short circuits for transformers 21
4.8Rated supply voltage of closing and opening devices and auxiliary and
control circuits (Ua) 21
4.9Rated supply frequency of closing and opening devices and of auxiliary
circuits 21
4.10Rated pressure of compressed gas supply for controlled pressure
systems 21
4.11Rated filling levels for insulation and/or operation 21
4.101Rated maximum power and class of enclosure 22
4.101.1Rated maximum power of the prefabricated substation 22
4.101.2Rated class of enclosure 22
4.102Ratings of the internal arc classification 22
4.102.1General 22
4.102.2Types of accessibility (A, B, AB) 22
4.102.3Rated arc fault currents (IA, IAe) 22
4.102.4Rated arc fault duration (tA, tAe) 23
5Design and construction 23
5.1Requirements for liquids in switchgear and controlgear 23
5.2Requirements for gases in switchgear and controlgear 23
5.3Earthing of switchgear and controlgear 24
5.4Auxiliary and control equipment 25
5.5Dependent power operation 25
5.6Stored energy operation 25
5.7Independent manual or power operation (independent unlatched
operation) 25
5.8Operation of releases 25
5.9Low- and high-pressure interlocking and monitoring devices 25
5.10Nameplates 25
5.11Interlocking devices 25
5.12Position indication 26
5.13Degree of protection provided by enclosures 26
5.14Creepage distances for outdoor insulators 26
5.15Gas and vacuum tightness 26
5.16Liquid tightness 26
5.17Fire hazard (flammability) 26
5.18Electromagnetic compatibility (EMC) 26
5.101Protection of the prefabricated substation against mechanical stress 26
5.102Protection of the environment due to internal defects 27
5.103Internal arc fault 27
5.104Enclosure 28
5.104.1General 28
5.104.2Fire behaviour 28
5.104.3Corrosion 29
5.104.4Covers and doors 30
5.104.5Ventilation openings 30
5.104.6Partitions 30
5.105Other provisions 31
5.105.1Provisions for dielectric tests on cables 31
5.105.2Accessories 31
5.105.3Operation aisle 31
5.105.4Labels 31
5.106Sound emission 31
5.107Electromagnetic fields 31
Type tests 31
6.1General 31
6.1.1Grouping of tests 32
6.1.2Information for identification of specimens 32
6.1.3Information to be included in type-test reports 32
6.2Dielectric tests 33
6.2.1Ambient air conditions during tests 33
6.2.2Wet test procedure 33
6.2.3Conditions of switchgear and controlgear during dielectric
tests 33
6.2.4Criteria to pass the test 33
6.2.5Application of the test voltage and test conditions 33
6.2.6Tests of switchgear and controlgear of Ur ≤ 245 kV 33
6.2.7Tests of switchgear and controlgear of Ur > 245 kV 33
6.2.8Artificial pollution tests for outdoor insulators 33
6.2.9Partial discharge tests 33
6.2.10Dielectric tests on auxiliary and control circuits 34
6.2.11Voltage test as condition check 34
6.2.101Tests on the high-voltage interconnection 34
6.2.102Tests on low-voltage interconnection 35
6.3Radio interference voltage (r.i.v.) test 36
6.4Measurement of the resistance of circuits 36
6.5Temperature-rise tests 36
6.5.101General 36
6.5.102Test conditions 37
6.5.103Test methods 38
6.5.104Measurements 41
6.5.105Acceptance criteria 42
6.6Short-time withstand current and peak withstand current tests 43
6.7Verification of the protection 43
6.8Tightness tests 43
6.9Electromagnetic compatibility tests (EMC) 43
6.10Additional tests on auxiliary and control circuits 44
6.10.1General 44
6.10.2Functional tests 44
6.10.3Electrical continuity of earthed metallic parts test 44
6.10.4Verification of the operational characteristics of auxiliary
contacts 44
6.10.5Environmental tests 44
6.10.6Dielectric test 44
6.11X-radiation test procedures for vacuum interrupters 44
6.101Calculations and mechanical tests 44
6.101.1Wind pressure 44
6.101.2Roof loads 45
6.101.3Mechanical impacts 45
6.102Internal arc test 45
6.102.1General 45
6.102.2Test conditions 45
6.102.3Arrangement of the equipment 46
6.102.4Test procedure 46
Criteria to pass the test 46
6.102.6Test report 47
6.102.7Transferability of tests results 48
6.103Measurement or calculation of electromagnetic fields 48
7Routine tests 48
Replacement 49
7.101Dielectric test on the high voltage interconnection 49
7.102Voltage withstand tests on auxiliary circuits 49
7.103Functional tests 49
7.104Verification of correct wiring 49
7.105Tests after assembly on site 49
8Guide to the selection of prefabricated substation 49
Replacement 49
8.101General 49
8.102Selection of rated values 50
8.103Selection of class of enclosure 50
8.104Internal arc fault 50
8.104.1General 50
8.104.2Causes and preventive measures 51
8.104.3Supplementary protective measures 51
8.104.4Considerations for the selection and installation 53
8.104.5Internal arc test 53
8.104.6IAC classification 53
8.105Summary of technical requirements, ratings and optional tests 54
9Information to be given with enquiries, tenders and orders 58
9.1Information with enquiries and orders 58
9.2Information with tenders 59
10Transport, storage, installation, operation, maintenance 60
10.1Conditions during transport, storage and installation 60
10.2Installation 60
10.2.1Unpacking and lifting 61
10.2.2Assembly 61
10.2.3Mounting 61
10.2.4Connections 61
10.2.5Final installation inspection 61
10.2.6Basic input data by the user 61
10.2.7Basic input data by the manufacturer 61
10.3Operation 61
10.4Maintenance 62
10.101 Dismantling, recycling and disposal at the end-of-service life 62
11Safety 62
11.101Electrical aspects 62
11.102Mechanical aspects 62
11.103Thermal aspects 62
11.104Internal arc aspects 62
12Influence of the product on the environment 63
Annex AA (normative) Internal arc fault – Method to verify the internal arc
classification (IAC) 64
AA.1 General 64
AA.2 Room simulation 64
AA.3 Indicators (for assessing the thermal effects of the gases) 64
AA.3.1 General 64
AA.3.2 Arrangement of indicators 65
AA.4 Tolerances for geometrical dimensions of test arrangements 66
AA.5 Test parameters 67
AA.6 Test procedure 67
Annex BB (normative) Test to verify the sound level of a prefabricated substation 76
BB.1 Purpose 76
BB.2 Test specimen 76
BB.3 Test method 76
BB.4 Measurements 76
BB.5 Presentation and calculation of the results 76
Annex CC (normative) Mechanical impact test 78
CC.1 Test for the verification of the resistance to mechanical impact 78
CC.2 Apparatus for the verification of the protection against mechanical
damage 78
Annex DD (informative) Rating of transformers in an enclosure 80
DD.1 General 80
DD.2 Liquid-filled transformer 80
DD.3 Dry-type transformer 81
DD.4 Example 85
Annex EE (informative) Examples of earthing circuits 88
Annex FF (informative) Characteristics of enclosure materials 91
FF.1 Metals 91
FF.1.1 Coatings 91
FF.1.2 Paints 91
FF.2 Concrete 91
Bibliography 93
Figure 101 – Measurement of transformer temperature rise in ambient air: ∆t1 37
Figure 102 – Measurement of transformer temperature rise in an enclosure: ∆t2 37
Figure 103 – Diagram of the preferred temperature-rise test method 39
Figure 104 – Diagram of the alternative temperature-rise test method 40
Figure 105 – Diagram for open-circuit test 41
Figure AA.1 – Mounting frame for vertical indicators 68
Figure AA.2 – Horizontal indicators 68
Figure AA.3 – Arrangement of indicators 71
Figure AA.4 – Selection of tests on high voltage switchgear for class IAC-A 72
Figure AA.5 – Selection of tests on high voltage switchgear for class IAC-B 73
Figure AA.6 – Selection of tests on high voltage interconnections for class IAC-A 74
Figure AA.7 – Selection of tests on high voltage interconnections for class IAC-B 75
Figure CC.1 – Impact test apparatus 79
Figure DD.1 – Liquid-filled transformer load factor in an enclosure 81
Figure DD.2 – Dry-type transformer load factor outside of the enclosure 81
Figure DD.3 – Insulation class 105 °C (A) dry-type transformers load factor in an
enclosure 82
Figure DD.4 – Insulation class 120 °C (E) dry-type transformers load factor in an
enclosure 82
Figure DD.5 – Insulation class 130 °C (B) dry-type transformers load factor in an
enclosure 83
Figure DD.6 – Insulation class 155 °C (F) dry-type transformers load factor in an
enclosure 83
Figure DD.7 – Insulation class 180 °C (H) dry-type transformers load factor in an
enclosure 84
Figure DD.8 – Insulation class 200 °C (H) dry-type transformers load factor in an
enclosure 84
Figure DD.9 – Insulation class 220 °C (H) dry-type transformers load factor in an
enclosure 85
Figure EE.1 – Example of earthing circuits 88
Figure EE.2 – Example of earthing circuits 89
Figure EE.3 – Example within the framework serving as the main earthing conductor 90
Table 101 – Synthetic material characteristics 29
Table 102 – Locations, causes and examples of measures decreasing the probability
of internal arcs 52
Table 103 – Single phase-to-earth arc fault current depending on the network neutral
earthing 54
Table 104 – Summary of technical requirements and ratings for prefabricated
substations (1 of 4) 55
Table FF.1 – Treatment of coatings 91
Table FF.2 – Tests of coatings 91
Table FF.3 – Test of concrete 92
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –
Part 202: High-voltage/low-voltage prefabricated substation
1 General
1.1Scope
This part of IEC 62271 specifies the service conditions, rated characteristics, general structural requirements and test methods of high voltage/low voltage or low voltage/high voltage prefabricated substations, which are cable-connected, to be operated from inside (walk-in type) or outside (non-walk-in type) for alternating current of rated voltages above 1 kV and up to and including 52 kV on the high voltage side, and for one or more transformers for service frequencies up to and including 60 Hz for outdoor installation at locations with public accessibility and where protection of personnel is provided.
Prefabricated substations can be situated at ground level or partially or completely below ground level.
In general a prefabricated substation comprises an enclosure containing the following electrical components:
–power transformers;
–high voltage and low voltage switchgear and controlgear;
–high voltage and low voltage interconnections;
–auxiliary equipment and circuits.
However, relevant provisions of this standard are applicable to designs where not all these electrical components exist (for example, an installation consisting of power transformer and low voltage switchgear).
Non-prefabricated substations should comply with the applicable requirements of IEC 61936- 1:2010.
1.2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 60050-461 (all parts), International Electrotechnical Vocabulary (available at www.electropedia.org)
IEC 60068-2-75, Environmental testing – Part 2-75: Tests – Test Eh: Hammer tests
IEC 60076-1:2011, Power transformers – Part 1: General
IEC 60076-2:2011, Power transformers – Part 2: Temperature rise for liquid-immersed transformers
IEC 60076-3:2013, Power transformers – Part 3: Insulation levels, dielectric tests and external clearances in air
IEC 60076-5:2006, Power transformers – Part 5: Ability to withstand short circuit
IEC 60076-7:2005, Power transformers – Part 7: Loading guide for oil-immersed power transformers
IEC 60076-10:2001, Power transformers – Part 10: Determination of sound levels
IEC 60076-11:2004, Power transformers – Part 11: Dry-type transformers
IEC 60076-12:2008, Power transformers – Part 12: Loading guide for dry-type power transformers
IEC 60076-13:2006, Power transformers – Part 13: Self-protected liquid-filled transformers
IEC 60364-4-41:2005, Low-voltage electrical installations – Part 4-41: Protection for safety – Protection against electric shock
IEC 60529:1989, Degrees of protection provided by enclosures (IP Code)
Amendment 1:1999
Amendment 2:2013
IEC 60664-1:2007, Insulation coordination for equipment within low-voltage systems – Part 1: Principles, requirements and tests
IEC 60721-1:1990, Classification of environmental conditions – Part 1: Environmental parameters and their severities
Amendment 1:1992
Amendment 2:1995
IEC 60721-2-2:2012, Classification of environmental conditions – Part 2-2: Environmental conditions appearing in nature – Precipitation and wind
IEC 60721-2-4:1987, Classification of environmental conditions – Part 2: Environmental conditions appearing in nature – Solar radiation and temperature
Amendment 1:1988
IEC/TS 60815-1:2008, Selection and dimensioning of high-voltage insulators intended for use in polluted conditions – Part 1: Definitions, information and general principles
IEC 60947-1:2007, Low-voltage switchgear and controlgear – Part 1: General rules
IEC 61180-1:1992, High-voltage test techniques for low-voltage equipment – Part 1: Definitions, test and procedure requirements
IEC 61439-1:2011, Low-voltage switchgear and controlgear assemblies – Part 1: General rules
IEC 61439-2:2011, Low-voltage switchgear and controlgear assemblies – Part 2: Power switchgear and controlgear assemblies
IEC 62262:2002, Degrees of protection provided by enclosures for electrical equipment against external mechanical impacts (IK code)
IEC 62271-1:2007, High-voltage switchgear and controlgear – Part 1: Common specifications
Amendment 1:2011
IEC 62271-200:2011, 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 62271-201:2006, 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/TR 62271-208:2009, High-voltage switchgear and controlgear – Part 208: Methods to quantify the steady state, power-frequency electromagnetic fields generated by HV switchgear assemblies and HV/LV prefabricated substations
IEC/TR 62271-300:2006, High-voltage switchgear and controlgear – Part 300: Seismic qualification of alternating current circuit-breakers
ISO/IEC Guide 51:1999, Safety aspects – Guidelines for their inclusion in standards
ISO 1052:1982, Steels for general engineering purposes
ISO 1182:2010, Reaction to fire tests for products – Non-combustibility tests
ISO 1716:2010, Reaction to fire tests for products – Determination of the gross heat of combustion (calorific value)
ISO 6508-1:2005, Metallic materials – Rockwell hardness test – Part 1: Test method (scales A, B, C, D, E, F, G, H, K, N, T)
Bibliography
IEC 60050-441:1984, International Electrotechnical Vocabulary (IEV) – Chapter 441: Switchgear, controlgear and fuses
IEC 60050-461:2008, International Electrotechnical Vocabulary – Part 461: Electric cables
IEC 60059:1999, IEC standard current ratings
IEC 60068 (all parts), Environmental testing
IEC 60068-1:2013, Environmental testing – Part 1: General and guidance
IEC 60076 (all parts), Power transformers
IEC 60243-1:2013, Electric strength of insulating materials – Test methods – Part 1: Tests at power frequencies
IEC 60724:2000, Short-circuit temperature limits of electric cables with rated voltages of 1 kV (Um = 1,2 kV) and 3 kV (Um = 3,6 kV)
Amendment 1:2008
IEC/TR 61641:2008, Enclosed low-voltage switchgear and controlgear assemblies – Guide for testing under conditions of arcing due to internal fault
IEC 61936-1:2010, Power installations exceeding 1 kV a.c. – Part 1: Common rules
IEC 62271-4:2013, High-voltage switchgear and controlgear – Part 4: Handling procedures for sulphur hexafluoride (SF6) and its mixtures
IEC/TS 62271-304:2008, High-voltage switchgear and controlgear – Part 304: Design classes for indoor enclosed switchgear and controlgear for rated voltages above 1 kV up to and including 52 kV to be used in severe climatic conditions
IEC/TR 62655:2013, Tutorial and application guide for high-voltage fuses
IEC Guide 117:2010, Electrotechnical equipment – Temperatures of touchable hot surfaces
ISO 1460, Metallic coatings – Hot dip galvanized coatings on ferrous materials – Gravimetric determination of the mass per unit area
ISO 1461, Hot dip galvanized coatings on fabricated iron and steel articles – Specification and test methods
ISO/DIS 1920-2, Testing of concrete – Part 2: Properties of fresh concrete
ISO 1920-4, Testing of concrete – Part 4: Strength of hardened concrete
ISO 2081, Metallic and other inorganic coatings – Electroplated coatings of zinc with supplementary treatments on iron or steel
ISO 2409, Paints and varnishes – Cross-cut test
ISO 3231:1993, Paints and varnishes – Determination of resistance to humid atmospheres containing sulphur dioxide
ISO/DIS 4846 Concrete – Determination of scaling resistance of surfaces exposed to de-icing chemicals 1
ISO 7784 (all parts), Paints and varnishes – Determination of resistance to abrasion
ISO 9227, Corrosion tests in artificial atmospheres – Salt spray tests
ISO 10546, Chemical conversion coatings – Rinsed and non-rinsed chromate conversion coatings on aluminium and aluminium alloys
ISO 11408, Chemical conversion coatings – Black oxide coating on iron and steel – Specification and test methods
ISO 11997 (all parts), Paints and varnishes – Determination of resistance to cyclic corrosion conditions
ISO 12944 (all parts), Paints and varnishes – Corrosion protection of steel structures by protective paint systems
ISO 13732-1:2006, Ergonomics of the thermal environment – Methods for the assessment of human responses to contact with surfaces – Part 1: Hot surfaces
EN 206-1, Concrete – Part 1: Specification, performance, production and conformity
ASTM C94/C 94M, Standard specification for ready-mixed concrete