IEC TS 60815-1:2008

IEC/TS 60815-1
Edition 1.0 2008-10
TECHNICAL
SPECIFICATION
Selection and dimensioning of high-voltage insulators intended for use in
polluted conditions –
Part 1: Definitions, information and general principles

IEC/TS 60815-1:2008(E)
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IEC/TS 60815-1
Edition 1.0 2008-10
TECHNICAL
SPECIFICATION
Selection and dimensioning of high-voltage insulators intended for use in
polluted conditions –
Part 1: Definitions, information and general principles

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XA
ICS 29.080.10 ISBN 978-2-88910-301-0
– 2 – TS 60815-1 © IEC:2008(E)
CONTENTS
FOREWORD.4
1 Scope and object.6
2 Normative references .7
3 Terms, definitions and abbreviations .7
3.1 Terms and definitions .7
3.2 Abbreviations .9
4 Proposed approaches for the selection and dimensioning of an insulator.9
4.1 Approach 1.10
4.2 Approach 2.10
4.3 Approach 3.10
5 Input parameters for the selection and dimensioning of insulators .12
6 System requirements.12
7 Environmental conditions.13
7.1 Identification of types of pollution .13
7.1.1 Type A pollution .13
7.1.2 Type B pollution .14
7.2 General types of environments .14
7.3 Pollution severity.15
8 Evaluation of site pollution severity (SPS) .15
8.1 Site pollution severity .15
8.2 Site pollution severity evaluation methods .16
8.3 Site pollution severity (SPS) classes .17
9 Insulation selection and dimensioning .20
9.1 General description of the process .20
9.2 General guidance on materials .21
9.3 General guidance on profiles.21
9.4 Considerations on creepage distance and insulator length .23
9.5 Considerations for exceptional or specific applications or environments .23
9.5.1 Hollow insulators .23
9.5.2 Arid areas.24
9.5.3 Proximity effects.24
9.5.4 Orientation .24
9.5.5 Maintenance and palliative methods .25
Annex A (informative) Flowchart representation of the design approaches.26
Annex B (informative) Pollution flashover mechanisms .29
Annex C (normative) Measurement of ESDD and NSDD .32
Annex D (normative) Evaluation of type B pollution severity.38
Annex E (normative) Directional dust deposit gauge measurements .40
Annex F (normative) Use of laboratory test methods.44
Annex G (normative) Deterministic and statistical approaches for artificial pollution

test severity and acceptance criteria .45
Annex H (informative) Example of a questionnaire to collect information on the
behaviour of insulators in polluted areas.48
Annex I (informative) Form factor.51
Annex J (informative) Correspondence between specific creepage distance and USCD.52

TS 60815-1 © IEC:2008(E) – 3 –
Bibliography.53

Figure 1 – Type A site pollution severity – Relation between ESDD/NSDD and SPS for
the reference cap and pin insulator .18
Figure 2 – Type A site pollution severity – Relation between ESDD/NSDD and SPS for
the reference long rod insulator .18
Figure 3 – Type B site pollution severity – Relation between SES and SPS for
reference insulators or a monitor .19
Figure C.1 – Insulator strings for measuring ESDD and NSDD.32
Figure C.2 – Wiping of pollutants on insulator surface.34
Figure C.3 – Value of b .35
Figure C.4 – Relation betweenσ and Sa .36
Figure C.5 – Procedure for measuring NSDD.37
Figure E.1 – Directional dust deposit gauges .40
Figure G.1 – Illustration for design based on the deterministic approach.46
Figure G.2 – Stress/strength concept for calculation of risk for pollution flashover .46
Figure H.1 – Form factor.51

Table 1 – The three approaches to insulator selection and dimensioning .11
Table 2 – Input parameters for insulator selection and dimensioning.12
Table 3 – Directional dust deposit gauge pollution index in relation to SPS class.19
Table 4 – Correction of site pollution severity class as a function of DDDG NSD levels.19
Table 5 – Examples of typical environments .20
Table 6 – Typical profiles and their main characteristics .22
Table D.1 – Directional dust deposit gauge pollution index in relation to site pollution
severity class.42
Table D.2 – Correction of site pollution severity class as a function of DDDG NSD
levels.42
Table J.1 – Correspondence between specific creepage distance and unified specific
creepage distance .52

– 4 – TS 60815-1 © IEC:2008(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SELECTION AND DIMENSIONING OF HIGH-VOLTAGE INSULATORS
INTENDED FOR USE IN POLLUTED CONDITIONS –

Part 1: Definitions, information and general principles

FOREWORD
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