IEC 60120:2020

IEC 60120 ®
Edition 4.0 2020-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Ball and socket couplings of string insulator units – Dimensions

Assemblages à rotule des éléments de chaînes d’isolateurs – Dimensions

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IEC 60120 ®
Edition 4.0 2020-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Ball and socket couplings of string insulator units – Dimensions

Assemblages à rotule des éléments de chaînes d’isolateurs – Dimensions

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.080.10; 29.240.20 ISBN 978-2-8322-8475-9

– 2 – IEC 60120:2020 © IEC 2020
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Designated size of coupling . 7
5 Pin ball . 7
6 Socket . 7
7 Hook-on "GO" gauge . 7
8 Lower part of the insulator . 7
9 Locking device . 7
10 Dimensions of the pin ball. 8
11 Dimensions of the socket end . 9
12 Dimensions of the hook-on "GO" gauge . 10
13 Dimensions of twin-balled pins . 13
14 Dimensions of the hole for the split-pin . 13
15 Dimensions of the hole for the W-clip . 15
Annex A (informative) Extreme positions of the pin ball in the socket . 16
Annex B (normative) Recommended gauges . 18
Annex C (informative) Dimensions obtained by calculation. 35
Bibliography . 37

Figure 1 – Schematic of the pin ball . 8
Figure 2 – Schematic of the socket end . 9
Figure 3 – Schematic of the hook-on "GO" gauge . 10
Figure 4 – Schematic of twin-balled pins . 13
Figure 5 – Schematic of the hole for the split-pin . 14
Figure 6 – Schematic of the hole for the W-clip . 15
Figure A.1 – Sliding position of the pin ball (socket end) . 16
Figure A.2 – Over-tilting position of the pin ball in the socket end . 17
Figure B.1 – Schematic of ball part for pin ball . 19
Figure B.2 – Schematic of inspecting part for cap . 19
Figure B.3 – Schematic of pin "GO" gauge for ball height, shank diameter and shank
length . 20
Figure B.4 – Schematic of pin "GO" gauge for ball diameter . 22
Figure B.5 – Schematic of pin "NOT GO" gauge for ball height . 23
Figure B.6 – Schematic of pin "NOT GO" gauge for ball diameter . 25
Figure B.7 – Schematic of pin "NOT GO" gauge for shank diameter . 26
Figure B.8 – Schematic of socket "GO" gauge for entry height, entry width and neck
width . 27
Figure B.9 – Schematic of socket "GO" gauge for internal height and internal diameter . 29
Figure B.10 – Schematic of socket "NOT GO" gauge for entry height . 32
Figure B.11 – Schematic of socket "NOT GO" gauge for neck width . 34

Figure C.1 – Schematic of clearance between the pin ball and the socket end . 35
Figure C.2 – Effectiveness of locking the pin ball . 36

Table 1 – Dimensions of the pin ball . 8
Table 2 – Dimensions of the socket end . 9
Table 3 – Dimensions of the hook-on "GO" gauge . 11
Table 4 – Dimensions of twin-balled pins . 13
Table 5 – Dimensions of the hole for the split-pin . 14
Table 6 – Dimensions of the hole for the W-clip . 15
Table A.1 – Allowed deviation angle of pin . 16
Table A.2 – Allowed deviation angle of pin . 17
Table B.1 – Dimensions of pin "GO" gauge for ball height, shank diameter and shank
length . 21
Table B.2 – Dimensions of pin "GO" gauge for ball diameter . 23
Table B.3 – Dimensions of pin "NOT GO" gauge for ball height . 24
Table B.4 – Dimensions of pin "NOT GO" gauge for ball diameter . 25
Table B.5 – Dimensions of pin "NOT GO" gauge for shank diameter . 26
Table B.6 – Dimensions of socket "GO" gauge for entry height, entry width and neck
width . 27
Table B.7 – Dimensions of socket "GO" gauge for internal height and internal diameter. 30
Table B.8 – Dimensions of socket "NOT GO" gauge for entry height . 32
Table B.9 – Dimensions of socket "NOT GO" gauge for neck width . 34
Table C.1 – Clearance between the pin ball and the socket end . 35
Table C.2 – Effectiveness of locking the pin ball . 36

– 4 – IEC 60120:2020 © IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
BALL AND SOCKET COUPLINGS OF STRING
INSULATOR UNITS – DIMENSIONS
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accor
...