I.S. EN IEC 61439-1:2021

FOREWORD 8
INTRODUCTION 10
1 Scope 11
2 Normative references 11
3 Terms and definitions 14
5 Interface characteristics 33
6 Information 37
7 Service conditions 38
8 Constructional requirements 40
9 Performance requirements 57
10 Design verification 60
11 Routine verification 93
Annex A (normative) Minimum and maximum cross-section of copper cables suitable
for connection to terminals for external cables (see 88) 105
Annex B (normative) Method of calculating the cross-sectional area of protective
conductors with regard to thermal stresses due to currents of short duration 106
Annex C (informative) User information template 107
Annex D (informative) Design verification 111
Annex E (informative) Rated diversity factor 112
Annex F (normative) Measurement of clearances and creepage distances 117
Annex G (normative) Correlation between the nominal voltage of the supply system
and the rated impulse withstand voltage of the equipment 122
Annex H (informative) Operating current and power loss of copper cables 124
Annex I (informative) Thermal equivalent of an intermittent current 126
Annex J (normative) Electromagnetic compatibility (EMC)127
Annex K (normative) Operating current and power loss of bare copper bars 134
Annex L (informative) Guidance on verification of temperature-rise 137
Annex M (normative) Verification of the short-circuit withstand strength of busbar
structures by comparison with a reference design by calculation 142
Annex N (informative) List of notes concerning certain countries 146
Bibliography

This part of IEC 61439 lays down the general definitions and service conditions, construction requirements, technical characteristics and verification requirements for low-voltage switchgear and controlgear assemblies.