IEC 60255-27:2013

Measuring relays and protection equipment - Part 27: Product safety requirements

IEC 60255-27:2013 describes the product safety requirements for measuring relays and protection equipment having a rated a.c. voltage up to 1 000 V with a rated frequency up to 65 Hz, or a rated d.c. voltage up to 1 500 V. Above these limits, IEC 60664-1 is applicable for the determination of clearance, creepage distance and withstand test voltage. This standard details essential safety requirements to minimize the risk of fire and hazards caused by electric shock or injury to the user. This new edition includes the following significant technical changes with respect to the previous edition:
- the removal of tables and diagrams which are from other standards and referring instead directly to the source standard;
- all aspects of IEC 60255-5 have been covered and this standard will be withdrawn.

Relais de mesure et dispositifs de protection - Partie 27: Exigences de sécurité

La CEI 60255-27:2013 détaille les exigences de sécurité produit pour les relais de mesure et dispositifs de protection dont la tension assignée n'excède pas 1 000 V en courant alternatif avec une fréquence assignée jusqu'à 65 Hz ou 1 500 V en courant continu. Au-delà de ces limites, la CEI 60664-1 est applicable pour déterminer les distances dans l'air, les lignes de fuites et la valeur des tensions de tenue d'essai. Cette norme détaille les exigences fondamentales de sécurité pour minimiser le risque d'incendie et les dangers de choc électrique ou de blessure pour l'utilisateur. Cette nouvelle édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- le retrait des tableaux et diagrammes qui proviennent d'autres normes et référant plutôt directement à ces standards sources;
- tous les aspects de la CEI 60255-5 ont été couvert et cette norme sera retirée.

General Information

• Status: Published
• Publication Date: 14-Oct-2013
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 29.120.70 - Relays
• Technical Committee: TC 95 - Measuring relays and protection equipment
• Drafting Committee: MT 3 - TC 95/MT 3
• Current Stage: DELPUB - Deleted Publication
• Start Date: 29-Jun-2018
• Completion Date: 07-Feb-2023

Relations

• Replaces: IEC 60255-5:2000 - Electrical Relays - Part 5: Insulation coordination for measuring relays and protection equipment - Requirements and tests
• Effective Date: 05-Sep-2023
• Revises: IEC 60255-27:2005 - Measuring relays and protection equipment - Part 27: Product safety requirements
• Effective Date: 05-Sep-2023
• Revises: IEC 60255-27:2005/COR1:2007 - Corrigendum 1 - Measuring relays and protection equipment - Part 27: Product safety requirements
• Effective Date: 05-Sep-2023
• Revised: IEC 60255-27:2023 - Measuring relays and protection equipment - Part 27: Product safety requirements
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60255-27 ®
Edition 2.0 2013-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Measuring relays and protection equipment –
Part 27: Product safety requirements

Relais de mesure et dispositifs de protection –
Partie 27: Exigences de sécurité

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IEC 60255-27 ®
Edition 2.0 2013-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Measuring relays and protection equipment –

Part 27: Product safety requirements

Relais de mesure et dispositifs de protection –

Partie 27: Exigences de sécurité

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XD
ICS 29.120.70 ISBN 978-2-8322-1161-8

– 2 – 60255-27 © IEC:2013
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 9
2 Normative references . 10
3 Terms and definitions . 11
4 General safety requirements . 19
4.1 General . 19
4.2 Earthing requirements . 20
5 Protection against electric shock . 20
5.1 General . 20
5.1.1 Introductory remark . 20
5.1.2 Protection from contact with hazardous live parts . 20
5.1.3 Discharge of capacitors . 21
5.1.4 Protective impedance . 22
5.1.5 Accessible parts . 22
5.1.6 Bonding to the protective conductor . 25
5.1.7 Protective conductor connection . 26
5.1.8 High leakage current . 26
5.1.9 Solid insulation . 26
5.1.10 Clearances and creepage distances . 27
5.1.11 Functional earthing . 29
5.2 Single-fault conditions . 29
5.2.1 Testing in single-fault condition . 29
5.2.2 Application of single-fault condition . 30
5.2.3 Duration of tests . 31
5.2.4 Compliance . 32
6 Mechanical aspects . 33
6.1 Protection against mechanical hazards . 33
6.1.1 Stability . 33
6.1.2 Moving parts . 33
6.1.3 Edges and corners . 33
6.2 Mechanical requirements . 33
6.3 Mechanical security of terminations . 33
7 Flammability and resistance to fire . 33
7.1 General . 33
7.2 Rationale . 34
7.3 General hazards from overheating and fire . 36
7.3.1 Equipment temperature limits . 36
7.3.2 Hazardous gases and chemicals. 36
7.4 Minimization of fire risk . 37
7.4.1 General . 37
7.4.2 Eliminating or reducing the sources of ignition within the equipment . 37
7.5 Cabling and fusing. 37
7.6 Flammability of materials and components . 38
7.6.1 General . 38
7.6.2 Materials for components and other parts inside fire enclosures . 38

60255-27 © IEC:2013 – 3 –
7.6.3 Materials for fire enclosures . 39
7.6.4 Materials for components and other parts outside fire enclosures . 39
7.7 Fire ignition sources . 40
7.8 Conditions for a fire enclosure . 40
7.8.1 General . 40
7.8.2 Parts requiring a fire enclosure . 40
7.8.3 Parts not requiring a fire enclosure . 40
7.9 Requirements for primary circuits and circuits exceeding ELV limits . 41
7.10 Fire enclosures and flame barriers . 41
7.11 Assessment of the fire risk due to a single-fault condition . 43
7.11.1 Guidelines for maximum acceptable temperatures when subjecting a
circuit or component to a single-fault condition . 43
7.11.2 Temperature of windings under a normal condition or a single-fault
condition . 43
7.11.3 Compliance of equipment with requirements for protection against
the spread of fire . 43
7.12 Limited-energy circuit . 44
8 General and fundamental design requirements for safety . 45
8.1 Climatic conditions for safety . 45
8.2 Electrical connections . 45
8.3 Components . 45
8.3.1 General . 45
8.3.2 High-integrity part or component . 45
8.4 Connection to telecommunication networks . 46
8.5 Connection to other equipment . 46
8.6 Laser sources . 46
8.7 Explosion . 46
8.7.1 General . 46
8.7.2 Components at risk of explosion . 46
9 Marking, documentation and packaging . 47
9.1 Marking . 47
9.1.1 General . 47
9.1.2 Identification . 48
9.1.3 Auxiliary supplies, VT, CT, I/O (Input/Output) . 48
9.1.4 Fuses .
...