IEC TS 62818-2:2024

Conductors for overhead lines - Fiber reinforced composite core used as supporting member material - Part 2: Metallic matrix composite cores

IEC TS 62818-2:2024 establishes a system of fiber reinforced composite cores used as supporting member material in conductors for overhead lines which may be used as the basis for specifications. This document is applicable to fiber reinforced composite core, with a metallic matrix, used as supporting member material in conductors for overhead lines.
This document gives guidance on:
- defining the common terms used for fiber reinforced composite cores with a metallic matrix,
- prescribing common methods and recommendations to characterize the properties of fiber reinforced composite cores based on single or multi-wires, with MMC (Metallic Matrix Composite) used as a supporting member material in conductors,
- prescribing or recommending acceptance or failure criteria when applicable.
These tests, criteria and recommendations are intended to ensure a satisfactory use and quality under normal operating and environmental conditions.
This document does not prescribe performance or compliance criteria which may be required but indicative values could be given in Annexes for guidance.

General Information

• Status: Published
• Publication Date: 04-Dec-2024
• ICS: 29.240.20 - Power transmission and distribution lines
• Technical Committee: TC 7 - Overhead electrical conductors
• Drafting Committee: PT 62818 - TC 7/PT 62818
• Current Stage: PPUB - Publication issued
• Start Date: 06-Dec-2024
• Completion Date: 05-Dec-2024

Standards Content (Sample)

IEC TS 62818-2 ®
Edition 1.0 2024-12
TECHNICAL
SPECIFICATION
colour
inside
Conductors for overhead lines – Fiber reinforced composite core used as
supporting member material –
Part 2: Metallic matrix composite cores

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IEC TS 62818-2 ®
Edition 1.0 2024-12
TECHNICAL
SPECIFICATION
colour
inside
Conductors for overhead lines – Fiber reinforced composite core used as

supporting member material –
Part 2: Metallic matrix composite cores

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.240.20  ISBN 978-2-8322-4949-9

– 2 – IEC TS 62818-2:2024 © IEC 2024
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Symbols and abbreviation terms . 9
5 Requirements . 9
5.1 Composite core manufacturing . 9
5.2 Composite core sampling and tests . 10
5.2.1 General . 10
5.2.2 Type tests . 10
5.2.3 Sample tests . 10
5.2.4 Routine tests . 10
5.3 Composite core traceability and packaging . 10
6 Composite core thermal performance . 11
6.1 General . 11
6.2 Maximum continuous temperature of the composite core: T . 11
C,CORE
6.3 Temperature limit for use in peak load of the composite core: T . 11
P,CORE
7 Tests for the composite core characterization . 12
7.1 General . 12
7.2 Tests for single wire . 12
7.2.1 Appearance (wire) . 12
7.2.2 Diameter (wire) . 12
7.2.3 Mass per unit length (wire) . 13
7.2.4 Coefficient of thermal expansion (wire) . 14
7.2.5 Mechanical properties – tensile breaking load (wire) . 14
7.2.6 Mechanical properties – flexural breaking load (wire) . 15
7.2.7 Isothermal aging (wire) . 17
7.2.8 DC electrical resistance (wire) . 17
7.2.9 Thermal Aging degradation test (Arrhenius method) (wire) . 17
7.3 Tests for stranded core (multi-wire core) . 18
7.3.1 Appearance (stranded core) . 18
7.3.2 Diameter (stranded core) . 18
7.3.3 Lay ratio (Lay Length) (stranded core) . 19
7.3.4 Lay direction . 19
7.3.5 Mass per unit length (stranded core) . 19
7.3.6 Mechanical properties – tensile breaking load (stranded core) . 19
7.3.7 Holding ability of retaining means (tape) . 20
7.3.8 Coefficient of thermal expansion (stranded core) . 20
8 Optional tests for the stranded composite core characterization . 21
8.1 Twisting test . 21
8.2 Crushing test . 22
8.3 Salt fog test . 23
8.4 Fiber volume ratio . 23
8.5 Porosity . 24
8.6 Bending test . 24

Annex A (normative) Testing table . 26
Annex B (normative) Arrhenius thermal aging test . 27
B.1 General . 27
B.2 Aging temperatures, number of samples and sampling frequency . 27
B.2.1 Planning for temperature and time . 27
B.2.2 Selection . 27
B.3 Test method . 28

Figure 1 – Measurement of multi-wire core diameter . 18
Figure 2 – CTE test setup . 21
Figure 3 – Illustration of the twisting test . 22
Figure 4 – Schematic of the crushing test . 23
Figure 5 – Illustration of the mandrel test . 25
Figure B.1 – Example of decay curves . 29
Figure B.2 – Example of decay curves and identification of times to end-point
according to method A . 29
Figure B.3 – Example of decay curves and identification of times to end-point
according to method B . 30
Figure B.4 – Example of Arrhenius curve with the long-term extrapolation to 40 years . 31

Table A.1 – Tests on composite core . 26

– 4 – IEC TS 62818-2:2024 © IEC 2024
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
CONDUCTORS FOR OVERHEAD LINES – FIBER REINFORCED
COMPOSITE CORE USED AS SUPPORTING MEMBER MATERIAL –

Part 2: Metallic matrix composite cores

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