LOW-VOLTAGE POWER SWITCHGEAR AND CONTROLGEAR …

1 GAMBICA Technical Guide LOW-VOLTAGE POWER SWITCHGEAR AND CONTROLGEAR ASSEMBLIES Edition 2: 2013 A guide to the requirements of: BS EN 61439 -1:2011 BS EN 61439 -2:2011 1 Foreword Under current electrical and safety legislation it is a requirement that equipment purchased within Europe (EEA) should be both fit for purpose and safe. Subject to any overriding national legislation, this may be demonstrated through meeting the requirements of European harmonised standards . These are implemented in the UK as BS EN standards . Following an extensive period of development, a new standard for Low Voltage SWITCHGEAR and CONTROLGEAR Assemblies has been introduced by the International Electrotechnical Commission (IEC) and subsequently adopted into European (EN) and National (BS) standards .

2 In the UK, the new standard is described and embodied within the BS EN 61439 series, replacing the BS EN 60439 series. Either series can be used until 1 November 2014. From that date BS EN 60439-1 is withdrawn and BS EN 61439 -1 and BS EN 61439 -2 should be used. Since the publication of IEC 61439 -2 other parts of the 61439 series have progressively been added until all parts of the 60439 series are now replaced. In addition IEC 61439 -1 and IEC 61439 -2 have been amended, clarified and refined, and issued as Edition 2. Accordingly, this guide has been revised to reflect the changes in the standard. Why a new standard? The new standard has been developed to simplify and clarify the means by which the performance of applicable products and assemblies can be verified against the requirements of the standards .

3 Some established definitions and practices have been radically revised and new methods of verification have been added. Whilst retaining critical safety-related technical performance requirements, the methods by which performance can be verified have variously been extended, simplified and made more accessible. In addition, the structure of the standard series has been radically modified to create a General Rules document with associated product-specific Parts. This is intended to make the standards simpler and more readily understood by product design engineers, consultants and end user customers for whom a clear understanding of the performance requirements and capability of equipment is critical.

4 This guide has been compiled by members of the GAMBICA CONTROLGEAR Group Technical Committee to provide specifiers, designers and purchasers of POWER SWITCHGEAR and CONTROLGEAR Assemblies (PSC-assemblies) with a clearer understanding of BS EN 61439 -2 and to assist in the selection of fully compliant and safe products in accordance with this standard. This guide is intended to complement the standard, not to be a substitute for it. The guide seeks to highlight the most relevant areas of the standard and to give the purchaser confidence in the safety and reliability of the equipment. In addition, it explains commonly used terminology and areas of customer choice to assist in the decision making process.

5 GAMBICA gratefully acknowledges the significant amount of time and effort put into the preparation of this guide by representatives of member companies. The greatest care has been taken to ensure the accuracy of the information contained in this guide, but no liability can be accepted by GAMBICA, or its members, for errors of any kind. 2013 The GAMBICA Association Ltd. This publication may be freely produced, in whole or part, provided its source is acknowledged. 2 Contents 1. POWER SWITCHGEAR AND CONTROLGEAR ASSEMBLIES (PSC-ASSEMBLIES) 3 So, what is a PSC-assembly? 4 Performance requirements 5 2.

6 DESIGN VERIFICATION 6 Strength of materials and parts 6 Enclosure and degree of protection 8 Clearances and creepage distance 8 Protection against electric shock and integrity of protective circuits 9 Internal faults 10 External faults 10 Incorporation of switching devices and components 11 Internal electrical circuits and connections 11 Terminals for external conductors 12 Dielectric properties 12 Temperature rise limits 13 Short-circuit withstand strength 18 Electromagnetic compatibility (EMC) 21 Mechanical operation 21 3. ROUTINE VERIFICATION 22 4.

7 CONSIDERATIONS FOR SMALL ASSEMBLIES 23 5. THE SO-CALLED FAULT-FREE ZONE 25 6. FORMS OF INTERNAL SEPARATION (FORMS 1-4) 27 7. EUROPEAN DIRECTIVES 40 Introduction 40 The Low Voltage Directive 40 The EMC Directive 41 Other directives that address safety and/or EMC 44 ORDER CHECK LIST 45 3 1. POWER SWITCHGEAR and CONTROLGEAR Assemblies (PSC-assemblies) BSEN61439-2 is Part 2 of the 61439 series of standards , as shown in Figure 1, and is the product-specific part covering the requirements for POWER SWITCHGEAR and CONTROLGEAR Assemblies (PSC-assemblies). BS EN 61439 -1: General rules BS EN 61439 -2: POWER SWITCHGEAR and CONTROLGEAR ASSEMBLIES BS EN 61439 -3: Distribution boards (superseded BS EN 60439-3) BS EN 61439 -4: ASSEMBLIES for construction sites (superseded IEC 60439-4) BS EN 61439 -5: ASSEMBLIES for POWER distribution (superseded IEC 60439-5) BS EN 61439 -6: Busbar trunking systems (superseded IEC 60439-2).

8 BS EN 61439 -7: Assemblies for specific installations at public sites such as marinas, camping sites, market squares and similar applications and for charging stations for Electrical Vehicles. (New Part being developed to cover assemblies with recently identified and particular needs) An IEC/TR 61439 -0 Specifier s Guide has also been published. Figure 1: The BS EN 61439 series of standards The General rules document BS EN 61439 -1(Part 1) is not a product standard in its own right and as such, no assembly can be declared as compliant to Part 1. The particular part (Parts 2- 7) applicable to the assembly in question must be read in conjunction with Part 1 which defines and declares requirements common to more than one assembly type.

9 Therefore, for PSC-assemblies Part 2 has to be read in conjunction with Part 1. The other product-specific parts, which also have to be read in conjunction with Part 1, deal with the particular requirements for certain specialized forms of assemblies. In standards terminology, LOW-VOLTAGE control panels, motor control centres, distribution boards and the like are known collectively as POWER SWITCHGEAR and CONTROLGEAR assemblies , or PSC-assemblies for short. By LOW-VOLTAGE is meant voltages up to 1000 V or 1500 V The need to conform to standards PSC-assemblies are typically subject to the Low Voltage Directive (LVD) and the EMC Directive.

10 These directives apply in all Member States of the EEA (European Economic Area comprising the EU Member States, Norway, Iceland and Liechtenstein). Note: Although not members of the EU or EEA, both Switzerland and Turkey have introduced legislation that allows CE marked product that complies with these directives to be placed on their respective markets without further testing. 4 Significantly, the requirements of these directives can be presumed to be met by electrical equipment which satisfies the provisions of certain European harmonised standards . In the case of PSC-assemblies, the relevant harmonised standard is BS EN 61439 -2.