SIST-TS CLC/TS 50539-12:2012

SLOVENSKI STANDARD
SIST-TS CLC/TS 50539-12:2012
01-februar-2012
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Low-voltage surge protective devices - Surge protective devices for specific application
including d.c. - Part 12: Selection and application principles - SPDs connected to
photovoltaic installations
Überspannungsschutzgeräte für Niederspannung - Überspannungsschutzgeräte für
besondere Anwendungen einschließlich Gleichspannung - Teil 12: Auswahl und
Anwendungsrichtlinien - Überspannungsschutzgeräte für den Einsatz in Photovoltaik
Installationen
Parafoudres basse tension - Parafoudres pour applications spécifiques incluant le
courant continu - Partie 12: Principes de choix et d’application - Parafoudres connectés
aux installations photovoltaïques
Ta slovenski standard je istoveten z: CLC/TS 50539-12:2010
ICS:
27.160 6RQþQDHQHUJLMD Solar energy engineering
29.120.50 9DURYDONHLQGUXJD Fuses and other overcurrent
PHGWRNRYQD]DãþLWD protection devices
SIST-TS CLC/TS 50539-12:2012 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST-TS CLC/TS 50539-12:2012

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SIST-TS CLC/TS 50539-12:2012

TECHNICAL SPECIFICATION
CLC/TS 50539-12

SPÉCIFICATION TECHNIQUE
March 2010
TECHNISCHE SPEZIFIKATION

ICS 29.120.50


English version


Low-voltage surge protective devices -
Surge protective devices for specific application including d.c. -
Part 12: Selection and application principles -
SPDs connected to photovoltaic installations



Parafoudres basse tension -  Überspannungsschutzgeräte
Parafoudres pour applications für Niederspannung -
spécifiques incluant le courant continu - Überspannungsschutzgeräte
Partie 12: Principes de choix für besondere Anwendungen
et d’application - einschließlich Gleichspannung -
Parafoudres connectés Teil 12: Auswahl
aux installations photovoltaïques und Anwendungsrichtlinien -
Überspannungsschutzgeräte
für den Einsatz in Photovoltaik
Installationen




This Technical Specification was approved by CENELEC on 2009-10-30.

CENELEC members are required to announce the existence of this TS in the same way as for an EN and to
make the TS available promptly at national level in an appropriate form. It is permissible to keep conflicting
national standards in force.

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



CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: Avenue Marnix 17, B - 1000 Brussels


© 2010 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. CLC/TS 50539-12:2010 E

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SIST-TS CLC/TS 50539-12:2012
CLC/TS 50539-12:2010 – 2 –
Foreword
This Technical Specification was prepared by the Technical Committee CENELEC TC 37A, Low voltage
surge protective devices.

The text of the draft was submitted to the formal vote and was approved by CENELEC as
CLC/TS 50539-12 on 2009-10-30.

Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent
rights.
The following date was fixed:
– latest date by which the existence of the CLC/TS

has to be announced at national level
(doa) 2010-04-30
__________

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Contents
Page
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 5
4 Systems and equipment to be protected . 6
4.1 Overvoltages in a PV installation . 6
4.2 Installation and location of SPDs . 6
4.3 Equipotential bonding . 9
4.4 Surge protective devices (SPD) in PV installations .10
4.5 Requirements for the implementation of SPDs .10
4.6 Selection and installation of SPDs for application in PV-Systems .11
4.7 Maintenance .16
Annex A (informative) Determination of the value of I for SPDs for structures protected by a
imp
LPS according to the simplified approach .17
Bibliography .19

Figures
Figure 1 – Possible installation of SPDs in case of a building without external LPS . 7
Figure 2 – Possible installation of SPDs in case of a building with external LPS when separation
distance s is kept . 7
Figure 3 – Possible installation of SPDs in case of a building with external LPS when separation
distance s is not kept . 8
Figure 4 – Possible installation of SPDs in case of a building with external LPS when separation
distance s is kept – Installation with data acquisition and control system . 8
Figure 5 – Building with external LPS – Dimensions of all equipotential bonding conductors are
6 mm² except the one indicated in the figure (earthing of the Type 1 SPD located at the origin
of installation) . 9
Figure 6 – Building with external LPS – Dimensions of equipotential bonding conductors in case of a
non insulated LPS .10
Figure 7 – Installation of SPDs on the AC-side and short distance between origin of installation and
PV-inverter (E < 10 m) .12
Figure 8 – Installation of SPDs on the AC-side and long distance between origin of installation and
PV-inverter (E > 10 m) .12
Figure 9 – Example of an overvoltage protection on DC side of a PV installation .14
Figure 10 – Surge protection on the DC side of unearthed PV systems .15
Figure 11 – Surge protection on the DC side of earthed PV systems .15

Tables
Table A.1 – Determination of the value of I on the AC side of PV generators .17
imp
Table A.2 – Determination of the value of I on the DC side of PV generators .18
imp

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SIST-TS CLC/TS 50539-12:2012
CLC/TS 50539-12:2010 – 4 –
1 Scope
This Technical Specification deals with the protection of PV installations against overvoltages. It deals
with the protection of the PV installation against surge overvoltages induced by direct and indirect
lightning strikes.
If such a PV installation is connected to an AC-supply system this document is applicable as a
complement of HD 60364-4-443, HD 60364-5-534 and HD 60364-7-712 and also CLC/TS 61643-12.
Surge protective devices (SPD) installed on the AC side shall comply with EN 61643-11.
NOTE 1 Due to the very specific electrical setup of PV installations on the DC side, only surge protective devices especially
dedicated to PV installations shall be used to protect the DC side of such installations.
NOTE 2 Taking into account the sensitivity and of the setting up of the photovoltaic modules, a detailed attention must be paid to
the protection of the structure itself (building) against direct effects of the lightning; this subject is covered by EN 62305 series.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 50164 series, Lightning Protection Components (LPC)
EN 60664-1, Insulation coordination for equipment within low-voltage systems – Part 1: Principles,
requirements and tests (IEC 60664-1)
EN 60904-3, Photovoltaic devices – Part 3: Measurement principles for terrestrial photovoltaic (PV) solar
devices with reference spectral irradiance data (IEC 60904-3)
EN 61000-4-5, Electromagnetic compatibility (EMC) – Part 4-5: Testing and measurement techniques –
Surge immunity test (IEC 61000-4-5)
EN 61643-11:2002 + A11:2007, Low-voltage surge protective devices – Part 11: Surge protective devices
connected to low-voltage power systems – Requirements and tests (IEC 61643-1:1998, mod. +
corrigendum Dec. 1998, mod.)
CLC/TS 61643-12:2006, Low-voltage surge protective devices – Part 12: Surge protective devices
connected to low-voltage power systems – Selection and application principles
(IEC 61643-12:2002, mod.)
EN 61643-21:2001, Low voltage surge protective devices – Part 21: Surge protective devices connected
to telecommunications and signalling networks – Performance requirements and testing methods
(IEC 61643-21:2000 + corrigendum Mar. 2001)
CLC/TS 61643-22:2006, Low-voltage surge protective devices – Part 22: Surge protective devices
connected to telecommunications and signalling networks – Selection and application principles
(IEC 61643-22:2004, mod.)
EN 62305-2:2006, Protection against lightning – Part 2: Risk management (IEC 62305-2:2006)
HD 60364-4-443:2006, Electrical installations of buildings – Part 4-44: Protection for safety – Protection
against voltage disturbances and electromagnetic disturbances – Clause 443: Protection against
overvoltages of atmospheric origin or due to switching (IEC 60364-4-44:2001/A1:2003, mod.)
HD 60364-5-534:2008, Low-voltage electrical installations – Part 5-53: Selection and erection of electrical
equipment – Isolation, switching and control – Clause 534: Devices for protection against overvoltages
(IEC 60364-5-53:2001/A1:2002 (Clause 534), mod.)

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HD 60364-7-712:2005, Electrical installations of buildings – Part 7-712: Requirements for special
installations or locations – Solar photovoltaic (PV) power supply systems (IEC 60364-7-712:2002)
ITU-T Recommendation K.20, Resistibility of telecommunication equipment installed in a
telecommunications centre to overvoltages and overcurrents
ITU-T Recommendation K.21, Resistibility of telecommunication equipment installed in customer
premises to overvoltages and overcurrents
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
PV-installation
erected equipment of a PV power supply system
3.2
lightning protection system
LPS
complete system used to reduce physical damage due to lightning flashes to a structure
NOTE It consists of both external and internal lightning protection systems.
[EN 62305-1:2006, Definition 3.40]
3.3
surge protective device
SPD
device that is intended to limit transient overvoltages and divert surge currents. It contains at least one
non-linear component
[EN 61643-11:2002, Definition 3.1]
3.4
external lightning protection system
part of the LPS consisting of an air-termination system, a down-conductor system and an earth-
termination system
3.5
separation distance
distance between two conductive parts at which no dangerous sparking can occur
[EN 62305-3:2006, Definition 3.28]
3.6
lightning equipotential bonding
EB
bonding to the LPS of separated conductive parts, by direct connections or via surge protective devices,
to reduce potential differences caused by lightning current
[EN 62305-3:2006, Definition 3.23]
3.7
bonding bar
metal bar on which metal installations, external conductive parts, electric power and telecommunication
lines, and other cables can be bonded to an LPS
[EN 62305-3:2006, Definition 3.24]
3.8
bonding conductor
conductor connecting separated conductive parts to LPS
[EN 62305-3:2006, Definition 3.25]

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SIST-TS CLC/TS 50539-12:2012
CLC/TS 50539-12:2010 – 6 –
3.9
standard test conditions
STC
test conditions specified in EN 60904-3 for PV cells and PV modules
3.10
open circuit voltage under standard test conditions
U
OC STC
voltage under standard test conditions across an unloaded (open) PV module, PV string, PV array, PV
generator or on the DC side of the PV-inverter
3.11
short-circuit current under standard test conditions
I
SC STC
short-circuit current of a PV module, PV string, PV array or PV generator under standard test conditions
4 Systems and equipment to be protected
When evaluating an PV-installation with regard to the use of an SPD, two factors need to be considered:
• the characteristics of the low-voltage power distribution system on which it will be used, including
expected types and levels of overvoltage and current;
• the characteristics of the equipment requiring protection.
4.1 Overvoltages in a PV installation
Overvoltages can be found under several conditions in a PV installation. They may be
• caused by direct strike to the external lightning protection system (LPS) of the building or lightning
flashes nearby the buildings and/or PV installations,
• caused by direct strikes and lightning induced currents distributed into the electrical network,
• transmitted from the distribution network. and being of atmospheric origin (lightning) and/or due to
operations,
• caused by variations of the electric field due to the lightning.
4.2 Installation and location of SPDs
According to CLC/TS 61643-12 and EN 62305 series, installation and location of SPDs for protection of
PV-Systems depends on multiple factors, the main ones being
• the flash ground density or keraunic level of the location,
• the presence of overhead lines,
• the characteristics of the low-voltage power distribution system (e.g. overhead network or not) and of
the equipment to be protected,
• if protection measures are needed to protect the PV-installation against direct lightning impacts with
an external LPS.
When installations are protected by an external LPS, the requirements on SPDs depends on
• the selected class of the LPS (see simplified method in Annex A),
• if the separation distance s is kept between the LPS and the PV installation (insulated LPS) or not
kept (non-insulated LPS).

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For further detail on external LPS and separation distance requirements see EN 62305-3.
NOTE EN 62305-3 defines external LPS isolated from the structure. In the present Technical Specification, the term “insulated” has
been used to avoid misinterpretation.
Examples for installation of SPDs for the different cases are shown in Figure 1 to Figure 4.
~ d.c.
a.c.
=
output input
equipotential
additional
bonding bar
earthing
connector
SPD: Surge Protective Device
meter/main main
earthing
distribution SPD Type 2 for PV application
bar
SPD Type 2
low
voltage SPD Type 2
Earth termination system

NOTE If the distance between the main distribution board and the inverter is greater than 10 m two sets of Type 2 SPDs are
required in location 2 and 3 (see 4.6.1.3). Two sets of Type 2 SPDs (not represented in the figure) are also required in location 1 if
the distance between the PV-panels and the inverter is greater than 10 m (see 4.6.2.4).
Figure 1 – Possible installation of SPDs in case of a building without external LPS
s
s
d.c.
~
a.c.
= input
output
s:    separation distance is kept
     (insulated LPS)
equipotential
SPD: Surge Protective Device
additional
bonding bar
earthing
connector
SPD Type 2 for PV application
SPD Type 2
main
meter/main
earthing SPD Type 1
distribution
bar
Air termination system
low voltage
power line
Down conductor
Earth termination system

NOTE If the distance between the main distribution board and the inverter is greater than 10 m two sets of SPDs are required in
location 2 and 3 (see 4.6.1.3). The SPD in location 3 shall be of Type1. Two sets of Type 2 SPDs (not represented in the figure) are
also required in location 1, if the distance between the PV-panels and the inverter is greater than 10 m (see 4.6.2.4).
Figure 2 – Possible installation of SPDs in case of a building with external LPS
when separation distance s is kept

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SIST-TS CLC/TS 50539-12:2012
CLC/TS 50539-12:2010 – 8 –
< s
< s
< s:  separation distance according to
a.c. d.c.     EN 62305 is not kept
~
=
output
input
SPD: Surge Protective Device
equipotential
additional
bonding bar
SPD Type 2 for PV application
earthing
connector
SPD Type 1
SPD Type 1
main
meter/main Air termination system
earthing
distribution
bar
Down conductor
low voltage
Connection between metal
power line
structure of PV system and LPS

Earth termination system
NOTE If the distance between the main distribution board and the inverter is greater than 10 m two sets SPDs are required in
location 2 and 3 (see 4.6.1.3). Two sets of SPDs are also required in location 1 (not represented in the figure) if the distance
between the PV-panels and the inverter is greater than 10 m (see 4.6.2.4). In that case AC and DC conductors act as parallel
conductors to the equipotential bonding conductors. Therefore all SPDs shall be Type 1.
Figure 3 – Possible installation of SPDs in case of a building with external LPS
when separation distance s is not kept
wind
sensor
s:    separation distance is kept
s
s
     (or insulated LPS)
SPD: Surge Protective Device
ACU: Acquisition and Control Unit
d.c.
~
input
a.c. = SPD Type 2 for PV application
output
SPD Type 2
equipotential
SPD Type 1
bonding bar
additional
earthing
SPD for signal line according to
connector
EN 61643-21
SPD (test impulse D1) for signal line
main
meter/main
earthing according to EN 61643-21
distribution
bar
Air termination system
signal line
Down conductor
low voltage Earth termination system
power line

NOTE For optimum inverter overvoltage protection it is recommended to add a direct earthing connection between SPD and
inverter.
Figure 4 – Possible installation of SPDs in case of a building with external LPS when separation
distance s is kept – Installation with data acquisition and control system

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4.3 Equipotential bonding
When the equipotential bonding conductors can be considered as a down conductor its minimum cross
section is 50 mm² copper or equivalent.
When the equipotential bonding conductors may carry partial lightning currents its minimum cross section
is 16 mm² copper or equi
...