IEC 61858-2:2014

Electrical insulation systems - Thermal evaluation of modifications to an established electrical insulation system (EIS) - Part 2: Form-wound EIS

IEC 61858-2:2014 lists the required test procedures for qualification of modifications of an established electrical insulation system (EIS) with respect to its thermal classification. This standard is applicable to EIS used in form-wound electrotechnical devices. The test procedures are comparative in that the performance of a candidate EIS is compared to that of a reference EIS, which has proven service experience in accordance with IEC 60505 or has been evaluated by one of the procedures given in IEC 60085 and IEC 60034-18-31.

Systèmes d'isolation électrique - Évaluation thermique des modifications apportées à un système d'isolation électrique (SIE) éprouvé - Partie 2: Système d'isolation électrique à enroulements préformés

L'IEC 61858-2:2014 énumère les procédures d'essai requises pour la qualification des modifications qui ont été apportées à un système d'isolation électrique (SIE) éprouvé, pour ce qui concerne sa classification thermique. La présente norme s'applique aux SIE utilisés dans les dispositifs électrotechniques à enroulements préformés. Les procédures d'essai sont comparatives en ce qu'elles se font par comparaison des performances d'un SIE candidat avec celles d'un SIE de référence dont l'expérience en service a été démontrée conformément à l'IEC 60505, ou qui a été évalué par l'une des procédures décrites dans l'IEC 60085 et l'IEC 60034-18-31.

General Information

• Status: Published
• Publication Date: 11-Feb-2014
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 29.080.30 - Insulation systems
• Technical Committee: TC 112 - Evaluation and qualification of electrical insulating materials and systems
• Drafting Committee: WG 6 - TC 112/WG 6
• Current Stage: PPUB - Publication issued
• Start Date: 30-Apr-2014
• Completion Date: 12-Feb-2014

Standards Content (Sample)

IEC 61858-2 ®
Edition 1.0 2014-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electrical insulation systems – Thermal evaluation of modifications to an
established electrical insulation system (EIS) –
Part 2: Form-wound EIS
Systèmes d'isolation électrique – Évaluation thermique des modifications
apportées à un système d’isolation électrique (SIE) éprouvé –
Partie 2: Système d’isolation électrique à enroulements préformés

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IEC 61858-2 ®
Edition 1.0 2014-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electrical insulation systems – Thermal evaluation of modifications to an

established electrical insulation system (EIS) –

Part 2: Form-wound EIS
Systèmes d'isolation électrique – Évaluation thermique des modifications

apportées à un système d’isolation électrique (SIE) éprouvé –

Partie 2: Système d’isolation électrique à enroulements préformés

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX T
ICS 29.080.30 ISBN 978-2-8322-1394-0

– 2 – 61858-2 © IEC:2014
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 General considerations . 9
5 Substitution of phase insulation and/or ground insulation . 11
5.1 Generically identical . 11
5.2 Substitution or addition of selected components and additives . 11
5.3 Reduction of thickness . 11
6 Substitution of winding wire . 12
6.1 Winding wire . 12
6.2 Substitution of conductor material . 13
6.3 Alternate winding wire . 13
7 Substitution of impregnating resin/varnish . 13
8 Evaluation of additions . 13
9 Procedure C – Single-point thermal ageing test . 13
9.1 Test objects . 13
9.2 Establishing the EIS relative thermal endurance index (EIS RTE) . 13
9.3 Interpretation of results . 14
10 Full thermal aging test (procedure D) . 14
Annex A (normative) Classes of winding wire . 15
Annex B (informative) Visual representation of form-wound coil manufacturing process . 16
Bibliography . 22

Figure 1 – Overview of evaluation methods . 10
Figure 2 – Substitution of phase and ground insulation . 11
Figure 3 – Substitution of winding wire . 12
Figure 4 – Substitution of conductor material . 12
Figure B.1 – Rectangular winding wire shaped into un-formed coil on coil forming
machine . 16
Figure B.2 – Un-formed coil being wrapped with a protective fabric . 17
Figure B.3 – Un-formed coil completely wrapped with protective fabric . 17
Figure B.4 – Coil forming machine stretches and bends oval coil to formed shape coil
in the shaping apparatus . 18
Figure B.5 – Formed coil with protective layer removed . 18
Figure B.6 – Close-up of formed coil’s knuckle insulation . 19
Figure B.7 – Formed coil with multiple layers of insulation . 19
Figure B.8 – Formed coils placed into the form-wound test specimen or Formette . 20
Figure B.9 – Insulation details . 21

Table A.1 – Winding wire type – Rectangular conductor . 15

61858-2 © IEC:2014 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICAL INSULATION SYSTEMS –
THERMAL EVALUATION OF MODIFICATIONS TO
AN ESTABLISHED ELECTRICAL INSULATION SYSTEM (EIS) –

Part-2: Form-wound EIS
FOREWORD
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