IEC TR 62271-312:2021

High-voltage switchgear and controlgear - Part 312: Guidance for the transferability of type tests of high-voltage/low-voltage prefabricated substations

IEC TR 62271-312:2021(E) refers to high-voltage / low-voltage prefabricated substations (hereinafter prefabricated substations) as specified in IEC 62271-202:2014.
This document, among other options as agreed between manufacturer and user, can be used for the transferability of type tests performed on one or more prefabricated substations with a defined set of ratings and arrangement of components to another prefabricated substation with a different set of ratings or different arrangement of components. It supports the selection of appropriate representative test objects for that purpose in order to optimize the type testing procedure for a consistent conformity assessment.
This document utilises a combination of sound technical and physical principles, manufacturer and user experience and mutually agreed upon methods of calculation to establish pragmatic guidance for the transferability of type test results, covering various design and rating aspects.

General Information

• Status: Published
• Publication Date: 04-Jan-2021
• ICS: 29.130.10 - High voltage switchgear and controlgear
• Technical Committee: SC 17C - Assemblies
• Current Stage: PPUB - Publication issued
• Start Date: 21-Jan-2021
• Completion Date: 05-Jan-2021

Standards Content (Sample)

IEC TR 62271-312 ®
Edition 1.0 2021-01
TECHNICAL
REPORT
colour
inside
High-voltage switchgear and controlgear –
Part 312: Guidance for the transferability of type tests of high-voltage/
low-voltage prefabricated substations

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IEC TR 62271-312 ®
Edition 1.0 2021-01
TECHNICAL
REPORT
colour
inside
High-voltage switchgear and controlgear –

Part 312: Guidance for the transferability of type tests of high-voltage/

low-voltage prefabricated substations

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.130.10 ISBN 978-2-8322-9228-0

– 2 – IEC TR 62271-312:2021 © IEC 2021
CONTENTS
FOREWORD . 6
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 Use of transferability criteria . 11
4.1 General . 11
4.2 Design parameters for transferability criteria . 12
4.3 Use of calculations . 12
4.3.1 General . 12
4.3.2 Temperature rise calculations . 13
4.3.3 Electric field calculations . 13
4.3.4 Electromagnetic field calculations . 13
4.3.5 Mechanical stress calculations. 13
4.3.6 Short-circuit current calculations . 13
4.3.7 Internal arc calculations . 14
4.4 Information needed for transferability of type test results . 14
5 Application of transferability criteria . 15
5.1 General . 15
5.2 Temperature rise tests . 15
5.3 Dielectric tests . 16
5.4 Electromagnetic field tests . 17
5.5 Mechanical tests . 19
5.6 Short-time withstand current and peak withstand current tests . 21
5.7 Internal arc tests . 22
6 Transferability of type test reports . 24
6.1 General . 24
6.2 Transferability of a type test report to another prefabricated substation
(situation a)) . 24
6.3 Validation of a substation design by existing type test reports (situation b)) . 25
6.4 Validation of a design modification (situation c)) . 26
Annex A (informative) Rationale for the transferability criteria . 27
A.1 General . 27
A.2 Temperature rise . 27
A.2.1 Layout and enclosure . 27
A.2.2 Ventilation openings (items 2.1, 2.2, 2.3 and 2.4 of Table 2) . 30
A.2.3 Distances between ventilation openings and power transformer (items 3
and 5 of Table 2) . 30
A.2.4 Clearance between low-voltage-switchgear and controlgear and the
power transformer (item 4 of Table 2) . 32
A.2.5 Power transformer insulation type (item 6 of Table 2) . 32
A.2.6 Power transformer total losses (item 7 of Table 2) . 32
A.2.7 Current of the low-voltage circuit (items 8 and 9 of Table 2) . 32
A.3 Dielectric . 33
A.3.1 General . 33
A.3.2 Clearances (items 2 and 3 of Table 3) . 33
A.3.3 Insulating supports and material (items 4 and 5 of Table 3) . 33
A.3.4 Live parts (items 6 and 7 of Table 3) . 33

A.4 Electromagnetic field . 34
A.4.1 General . 34
A.4.2 Substation layout and distance from components to external surfaces of
the enclosure (items 1 and 2 of Table 4) . 34
A.4.3 Rated voltages (item 3 of Table 4) . 36
A.4.4 Rated normal currents (item 4 of Table 4) . 36
A.4.5 Rated frequency (item 5 of Table 4) . 37
A.4.6 Permeability and conductivity of the enclosure material(s) (items 6 and
12 of Table 4) . 37
A.4.7 Interconnections (items 7, 8 and 9 of Table 4) . 38
A.4.8 Power transformer type of insulation (item 10 of Table 4) . 39
A.4.9 Distance between main circuit phases of the low-voltage switchgear and
controlgear (item 11 of Table 4) . 40
A.5 Mechanical stress . 40
A.5.1 General . 40
A.5.2 Common design parameters to be assessed for the key components . 40
A.5.3 Considerations for different enclosure materials, fasteners and

reinforcements (items 1, 2, 3 and 4 of Table 5) . 42
A.6 Short-time withstand current and peak withstand current . 43
A.6.1 General . 43
A.6.2 Rated short-time and peak currents (items 1 and 2 of Table 6) . 43
A.6.3 Rated duration of short-circuit (item 3 of Table 6) . 43
A.6.4 Centre distance between phase conductors (item 4 of Table 6) . 43
A.6.5 Conductors (items 5, 9 and 11 of Table 6) . 43
A.6.6 Insulating conductor supports (items 6, 7 and 8 of Table 6) . 44
A.6.7 Type of high-voltage and low-voltage terminations (item 10 of Table 6) . 44
A.6.8 Temperature class of insulating material in contact with conductors
(item 12 of Table 6) . 44
A.7 Internal arc . 44
A.7.1 General . 44
A.7.2 Rated arc fault current, arc fault peak current and arc fault duration
(items 1 and 2 of Table 7) . 45
A.7.3 High-voltage switchgear family (item 3 of Table 7) . 45
A.7.4 Layout of the prefabricated substation (item 4 of Table 7) . 46
A.7.5 Expansion volumes (items 5, 6 and 7 of Table 7) . 46
A.7.6 Cross-section of ventilation openings (item 8 of Table 7) . 51
A.7.7 Design, position, cross-section of the cooling device(s) and gas flow
(item 9 of Table 7) . 51
A.7.8 Distances between high-voltage switchgear and controlgear assembly
and the prefabricated substation enclosure (walls and roof) (item 10 of
Table 7) . 53
A.7.9 Mechanical strength of the enclosure (item 11 of Table 7) . 54
A.7.10 The shortest path length of hot gases in the last compartment to the
closest ventilation opening before leaving the substation (item 12 of
Table 7) . 54
A.7.11 Type of high-voltage interconnection and electrical protection of the
circuit (items 13 and 14 of Table 7) . 54
Annex B (informative) Collection of design parameters for the assessment of
transferability of type test results . 56
B.1 General . 56
B.2 Information needed for the assessment of the temperature-rise test . 56
B.3 Information needed for the assessment of the dielectric test . 57

– 4 – IEC TR 62271-312:2021 © IEC 2021
B.4 Information needed for the assessment of the electromagnetic field test . 58
B.5 Information needed for the assessment of the mechanical stress test . 59
B.6 Information needed for the assessment of the short-circuit current test . 59
B.7 Information needed for the assessment of the internal arc test . 60
Bibliography . 61

Figure 1 – Transferability of one type test report .
...