CLC/TR 50656:2016

SLOVENSKI STANDARD
01-april-2016
Uporaba SPD v povezavi z opremo razreda II
SPD application in conjunction with Class II equipment
SPD Anwendungen in Verbindung mit Schutzklasse II
Parafoudres destinés à être utilisés avec des équipements classe II
Ta slovenski standard je istoveten z: CLC/TR 50656:2016
ICS:
29.120.50 9DURYDONHLQGUXJD Fuses and other overcurrent
PHGWRNRYQD]DãþLWD protection devices
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL REPORT CLC/TR 50656

RAPPORT TECHNIQUE
TECHNISCHER BERICHT
March 2016
ICS 29.120.50
English Version
SPD application in conjunction with Class II equipment
Parafoudres destinés à être utilisés avec des équipements SPD Anwendungen in Verbindung mit Schutzklasse II
classe II
This Technical Report was approved by CENELEC on 2015-12-14.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. CLC/TR 50656:2016 E
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
3.1 SPD assembly one SPD or a set of SPDs, in both case including all SPD disconnectors
required by the SPD manufacturer, providing the required overvoltage protection for a
type of system earthing . 5
3.2 extraneous conductive part conductive part not forming part of the electrical installation
and liable to introduce an electric potential, generally the electric potential of a local earth . 5
3.3 functional earth . 5
3.4 class II SPD . 6
3.5 protective earthing. 6
3.6 protective conductor . 6
3.7 protective earthing conductor . 6
4 SPDs connected to PE for the protection of Class II equipments . 6
4.1 General . 6
4.2 TN System . 8
4.3 TT System . 9
4.4 IT System . 10
4.5 Example of lighting pole surge protection connected to PE . 11
5 SPDs not connected to PE for the protection of Class II equipments . 11
5.1 General . 11
5.2 Examples . 12
6 Additional requirements for SPDs to comply with equipment class II design rules (Double
or reinforced insulation) . 14
6.1 General . 14
6.2 Requirements for basic protection (protection against direct contact) and fault protection
(protection against indirect contact) . 15
6.2.1 Class II SPD . 15
6.2.2 Enclosures . 16
Annex A (normative) Test to establish whether a conductive part may cause an electric shock . 18
European foreword
This document (CLC/TR 50656:2016) has been prepared by CLC/TC 37A “Low voltage surge protective
devices”.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such patent rights.
Introduction
Based on questions and requests from the field it was felt necessary to provide some guidance and
instructions how and in which applications currently available SPDs according to EN 61643-11 can be
correctly and safely applied in conjunction with class II equipment and in installations, where the protective
measure double or reinforced insulation is applied (see HD 60364-4-41 and EN 61140).
In general current SPDs according EN 61643-11 are designed to properly protect wherever:
— basic insulation is required e.g. between active parts and the protective equipotential bonding system
(PE) (the SPD bridges basic insulation in such applications);
— basic or functional insulation is required e.g. between active parts of different potential (the SPD bridges
basic or functional insulation in such applications).
The requirements currently contained in EN 61643-11 do not cover requirements for SPD applications, where
the SPD bridges double or reinforced insulation, like e.g. between primary and secondary side of an isolating
transformer (protective separation) or between active parts and touchable conductive surfaces of class II
equipment.
There are attempts to develop requirements for such SPDs, but for the time being there is no defined solution.
This document refers to HD 60364-4-41 for topics related to installation rules and to EN 62368-1 for some
equipments related topics.
This document specially addresses installation issues related to street lighting.
1 Scope
In addition to CLC/TS 61643-12, this Technical Report describes the principle of erecting SPDs to be
connected to 50 Hz a.c. power circuits, rated up to 1 000 V r.m.s. in conjunction with Class II equipments.
In addition to EN 61643-11, this Technical Report gives specific guidance for SPDs intended to be installed in
class II equipments.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
EN 50539-11:2013, Low-voltage surge protective devices - Surge protective devices for specific application
including d.c. - Part 11: Requirements and tests for SPDs in photovoltaic applications
EN 60529, Degrees of protection provided by enclosures (IP Code) (IEC 60529)
EN 60664-1, Insulation coordination for equipment within low-voltage systems — Part 1: Principles,
requirements and tests (IEC 60664-1)
EN 60950-1, Information technology equipment — Safety — Part 1: General requirements (IEC 60950-1)
EN 61643-11:2012, Low-voltage surge protective devices — Part 11: Surge protective devices connected to
low-voltage power systems — Requirements and test methods (IEC 61643-11:2011)
EN 62368-1:2014, Audio/video, information and communication technology equipment — Part 1: Safety
requirements (IEC 62368-1:2014, modified)
HD 60364 (all parts), Low-voltage electrical installations (IEC 60364, all parts)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

http://www.cenelec.eu/dyn/www/f?p=104:110:695920932773601::::FSP_ORG_ID,FSP_PROJECT,FSP_LANG_ID:125802
5,43747,25
http://www.cenelec.eu/dyn/www/f?p=104:110:379108178804401::::FSP_ORG_ID,FSP_PROJECT,FSP_LANG_ID:125849
7,50513,25
http://www.cenelec.eu/dyn/www/f?p=104:110:1457986987015001::::FSP_ORG_ID,FSP_PROJECT,FSP_LANG_ID:12571
89,53711,25
http://www.cenelec.eu/dyn/www/f?p=104:110:592568428155801::::FSP_ORG_ID,FSP_PROJECT,FSP_LANG_ID:125861
7,43963,25
http://www.cenelec.eu/dyn/www/f?p=104:110:785888442943801::::FSP_ORG_ID,FSP_PROJECT,FSP_LANG_ID:125718
9,60205,25
http://www.cenelec.eu/dyn/www/f?p=104:110:437816408653901::::FSP_ORG_ID,FSP_PROJECT,FSP_LANG_ID:125716
3,57623,25
3.1
SPD assembly
one SPD or a set of SPDs, in both case including all SPD disconnectors required by the SPD manufacturer,
providing the required overvoltage protection for a type of system earthing
[SOURCE: IEC 60364-5-53, modified]
3.2
extraneous conductive part
conductive part not forming part of the electrical installation and liable to introduce an electric potential,
generally the electric potential of a local earth
[SOURCE: IEC 60050-826]
3.3
functional earth
earthing a point or points in a system or in an installation or in equipment, for purposes other than electrical
safety
[SOURCE: EN 62368-1:2014]
3.4
class II SPD
SPDs in which protection against electric shock does not rely on basic insulation only, but in which additional
safety precautions such as double insulation or reinforced insulation are provided, there being no provision for
protective earthing or reliance upon installation conditions
Note 1 to entry: Such a SPD may have a substantially continuous enclosure of metal, insulated from live parts by
insulation at least equivalent to double or reinforced insulation. Such a SPD is called a metal-encased class II SPD.
Note 2 to entry: The enclosure of an insulation-encased class II SPD may form a part or the whole of the
supplementary insulation or the reinforced insulation.
Note 3 to entry: If a SPD with double insulation and/or reinforced insulation throughout has a protective earthing, it is
class I construction,
Note 4 to entry: Class II SPD may have parts in which protection against electric shock relies on operation at safety
extra-low voltage (SELV).
Note 5 to entry: Such SPDs should be marked with the symbol .
[SOURCE: EN 60598-1:2015, modified]
3.5
protective earthing
earthing a point or points in a system or in an installation or in equipment for purposes of electrical safety
[SOURCE: EN 62368-1:2014, modified]
3.6
protective conductor
conductor provided for the purposes of safety (for example, protection against electric shock)

http://www.cenelec.eu/dyn/www/f?p=104:110:1827578021514001::::FSP_ORG_ID,FSP_PROJECT,FSP_LA
NG_ID:1257233,50934,25
Note 1 to entry: A protective conductor is either a protective earthing conductor or a protective bonding conductor.
[SOURCE: EN 62368-1:2014]
3.7
protective earthing conductor
protective conductor connecting a main protective earthing terminal in the equipment to an earth point in the
building installation for protective earthing
[SOURCE: EN 62368-1:2014]
4 SPDs connected to PE for the protection of Class II equipments
4.1 General
In the four following examples, a Class II equipment is integrated into a conductive metallic housing that is
connected to PE (i.e. Class I equipment)
...