IEC 60287-2-1:2023

Electric cables - Calculation of the current rating - Part 2-1: Thermal resistance - Calculation of thermal resistance

IEC 60287-2-1:2023 is solely applicable to the conditions of steady-state operation of cables at all alternating voltages, and direct voltages up to 5 kV, buried directly in the ground, in ducts, in troughs or in steel pipes, both with and without partial drying-out of the soil, as well as cables in air. The term "steady state" is intended to mean a continuous constant current (100 % load factor) just sufficient to produce asymptotically the maximum conductor temperature, the surrounding ambient conditions being assumed constant.

General Information

• Status: Published
• Publication Date: 21-May-2023
• ICS: 29.060.20 - Cables
• Technical Committee: TC 20 - Electric cables
• Drafting Committee: WG 19 - TC 20/WG 19
• Current Stage: PPUB - Publication issued
• Start Date: 09-Jun-2023
• Completion Date: 22-May-2023

Relations

• Revises: IEC 60287-2-1:2015 - Electric cables - Calculation of the current rating - Part 2-1: Thermal resistance - Calculation of the thermal resistance
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60287-2-1
®

Edition 3.0 2023-05
INTERNATIONAL
STANDARD



Electric cables – Calculation of the current rating –
Part 2-1: Thermal resistance – Calculation of thermal resistance

IEC 60287-2-1:2023-05(en)

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IEC 60287-2-1

®


Edition 3.0 2023-05




INTERNATIONAL



STANDARD




















Electric cables – Calculation of the current rating –

Part 2-1: Thermal resistance – Calculation of thermal resistance


























INTERNATIONAL

ELECTROTECHNICAL


COMMISSION





ICS 29.060.20  ISBN 978-2-8322-6981-7




  Warning! Make sure that you obtained this publication from an authorized distributor.


® Registered trademark of the International Electrotechnical Commission

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– 2 – IEC 60287-2-1:2023 © IEC 2023
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms, definitions and symbols . 8
3.1 Terms and definitions. 8
3.2 Symbols . 8
4 Calculation of thermal resistances . 11
4.1 Thermal resistance of the constituent parts of a cable, T , T and T . 11
1 2 3
4.1.1 General . 11
4.1.2 Thermal resistance between one conductor and sheath T . 11
1
4.1.3 Thermal resistance of any generic annular layer . 15
4.1.4 Thermal resistance between sheath and armour T . 15
2
4.1.5 Thermal resistance of outer cover
...