EN IEC 62892:2019

Extended thermal cycling of PV modules - Test procedure

This document defines a test sequence that extends the thermal cycling test of IEC 61215-2. It is intended to differentiate PV modules with improved durability to thermal cycling and evaluate modules for deployment in locations most susceptible to thermal cycling type stress1. This document is based on the ability for 95 % of the modules represented by the samples submitted for this test to pass an equivalency of 500 thermal cycles, as defined in IEC 61215-2:2016, 4.11.3, with a maximum power degradation of less than 5 %. Provisions are also provided to reduce overall test time by increasing the maximum cycle temperature and/or the number of modules submitted for test. The test procedure in this document was developed based on analysis of the stress on tin-lead solder bonds on crystalline silicon solar cells in a glass superstrate type package. Changes to lead-free solder have an effect on the acceleration factors but not enough to change the overall results of this test. Monolithic type modules with integral cell interconnection do not suffer from this specific type of stress but there are still electrical connections within the module, for example between the integrated cell circuit and the module bus bars, that may be subject to wear out from thermal cycling. Flexible modules (without glass) are not stressed in the same way as those with glass superstrates or substrates, therefore use of the equivalency factor employed in this document may not be applicable to these modules.

Erweiterte Temperaturwechselprüfung von PV-Modulen

Cycle thermique étendu de modules PV - Procédure d'essai

l'IEC 62892:2019 définit une séquence d'essais qui étend l'essai de cycle thermique de l'IEC 61215-2. Il est destiné à différencier les modules photovoltaïques avec une meilleure durabilité par rapport au cycle thermique et à évaluer les modules pour un déploiement dans les lieux plus exposés aux contraintes de cycle thermique. Le présent document repose sur l'aptitude pour 95 % des modules représentés par les échantillons soumis à cet essai à supporter avec succès l'équivalent de 500 cycles thermiques, conformément à la procédure définie dans l'IEC 61215-2:2016, 4.11.3, avec une dégradation maximale de puissance inférieure à 5 %. Des dispositions sont également fournies pour réduire la durée totale des essais en augmentant la température maximale du cycle et/ou le nombre de modules soumis à l'essai. La procédure d'essai décrite dans le présent document a été élaborée sur la base d'une analyse des contraintes exercées sur des assemblages soudés en alliage plomb-étain sur des cellules solaires en silicium cristallin au sein d'un ensemble de type superstrat de verre. Des modifications apportées à une soudure sans plomb ont un effet sur les facteurs d'accélération, mais pas de manière suffisante pour modifier les résultats globaux de cet essai. Les modules de type monolithique avec interconnexion intégrale des cellules ne souffrent pas de ce type de contrainte spécifique, mais il persiste des connexions électriques à l'intérieur du module, par exemple entre le circuit intégré de la cellule et les barres omnibus du module, qui peut subir une usure due aux cycles thermiques. Les modules souples (sans verre) ne subissent pas les mêmes contraintes que ceux qui comportent des superstrats ou des substrats de verre. Par conséquent, l'utilisation du facteur d'équivalence employé dans le présent document peut ne pas convenir à ces modules.

Razširjeni ciklični temperaturni preskus PV-modulov - Preskusna metoda

Ta dokument opredeljuje preskusno zaporedje razširjenega cikličnega temperaturnega preskusa iz standarda IEC 61215-2. Namenjen je razvrščanju in ocenjevanju PV-modulov na podlagi izboljšane odpornosti na ciklične temperaturne obremenitve, ki jih nameravamo namestiti na lokacijah, ki so najbolj občutljive na temperaturne cikle1. Ta dokument temelji na predpostavki, da 95 % modulov, ki jih predstavljajo vzorci preskusa, opravijo preskušanje, enakovredno 500 temperaturnim ciklom, kot je opredeljeno v standardu IEC 61215-2:2016, 4.11.3, z največjo degradacijo moči manj kot 5 %. Vsebuje tudi določila za skrajšanje celotnega časa preskusa, če se poveča najvišja temperatura cikla in/ali število modulov, predloženih v preskus.
Postopek preskusa v tem dokumentu je bil razvit na podlagi analize obremenitve mehko spajkanih spojev na sončnih celicah iz kristalnega silicija, nanesenih na steklo v superstratni konfiguraciji. Če so spoji brez svinca, to vpliva na faktorje pospeška, vendar ne toliko, da bi se spremenili splošni rezultati tega preskusa. Omenjena obremenitev ne vpliva na monolitne module z integrirano celično povezavo, vendar so znotraj modula še vedno električne povezave, na primer med integriranim celičnim vezjem in vodili modulov, ki se lahko zaradi temperaturnega cikla obrabijo. Prilagodljivi moduli (brez stekla) niso obremenjeni enako kot tisti, naneseni na steklo v superstratni konfiguraciji ali na drugih podlagah, zato uporaba faktorja enakovrednosti, uporabljenega v tem dokumentu, morda ne bo uporabna za te module.

General Information

• Status: Published
• Publication Date: 06-Jun-2019
• Withdrawal Date: 21-May-2022
• ICS: 27.160 - Solar energy engineering
• Technical Committee: CLC/TC 82 - Solar photovoltaic energy systems
• Drafting Committee: IEC/TC 82 - IEC_TC_82
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 07-Jun-2019
• Completion Date: 07-Jun-2019
• Ref Project: SIST EN IEC 62892:2019 - Extended thermal cycling of PV modules - Test procedure

Overview

EN IEC 62892:2019 - Extended thermal cycling of PV modules - is a CLC-adopted test procedure that extends the thermal cycling requirements of IEC 61215-2. It provides a standardized, accelerated thermal-cycling sequence intended to differentiate PV modules with improved durability to temperature‑change stress and to evaluate modules for deployment in climates that are most susceptible to thermal‑cycling damage. The method is based on the expectation that 95% of the tested population will show equivalency to 500 thermal cycles (as per IEC 61215-2:2016, clause 4.11.3) with a maximum power degradation of less than 5%.

Key topics and technical requirements

• Extended thermal cycling sequence: A defined procedure that supplements IEC 61215-2 to increase stress exposure for thermal fatigue assessment.
• Pass criteria: Equivalency target of 500 cycles and ≤5% maximum power loss for 95% survivorship.
• Sampling & reporting: Requirements for sample selection, documentation, test monitoring and final evaluation are specified (sampling, marking, reporting).
• Acceleration options: Provisions to reduce overall test time by raising the maximum cycle temperature and/or increasing the number of modules under test.
• Failure mechanisms considered: Procedure is developed from analysis of stress on tin‑lead solder bonds in crystalline‑silicon, glass‑superstrate modules. Lead‑free solder alters acceleration factors but does not change the overall test outcome.
• Scope limitations: Monolithic modules with integral interconnects and flexible (non‑glass) modules are noted to experience different stress modes; the equivalency factor used here may not be applicable to all such designs.
• Supporting material: Annex A covers calculation of required number of thermal cycles; Annex B provides acceleration factors and guidance on climate-driven applicability.

Applications and users

This standard is practical for:

• PV module manufacturers assessing long‑term durability to thermal cycling and comparing designs.
• Independent test laboratories implementing extended thermal‑fatigue qualification procedures.
• Certification bodies and procurement teams specifying durability requirements for modules intended for thermally aggressive climates.
• R&D, reliability engineers and quality assurance teams developing module designs and solder/interconnect strategies.
• Project developers and system integrators evaluating module suitability for locations with large diurnal temperature swings.

Keywords: EN IEC 62892:2019, extended thermal cycling, PV modules, thermal cycling test, IEC 61215, accelerated testing, thermal stress, solder fatigue, crystalline silicon.

Related standards

• IEC 61215 series (design qualification & type approval)
• IEC 61730 (PV module safety qualification)
• IEC/TS 62941, IEC/TS 62915 and related guidance documents referenced in EN IEC 62892:2019 for sampling, retesting and quality system context.

Standards Content (Sample)

SLOVENSKI STANDARD
01-november-2019
Razširjeni ciklični temperaturni preskus PV-modulov - Preskusna metoda
Extended thermal cycling of PV modules - Test procedure
Procédure d'essai pour cycle thermique étendu de modules PV
Ta slovenski standard je istoveten z: EN IEC 62892:2019
ICS:
27.160 Sončna energija Solar energy engineering
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 62892

NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2019
ICS 27.160
English Version
Extended thermal cycling of PV modules - Test procedure
(IEC 62892:2019)
Cycle thermique étendu de modules PV - Procédure d'essai Erweiterte Temperaturwechselprüfung von PV Modulen
(IEC 62892:2019) (IEC 62892:2019)
This European Standard was approved by CENELEC on 2019-05-22. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
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, Serbia, 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: Rue de la Science 23, B-1040 Brussels
© 2019 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.

Ref. No. EN IEC 62892:2019 E
European foreword
The text of document 82/1537/FDIS, future edition 1 of IEC 62892, prepared by IEC/TC 82 "Solar
photovoltaic energy systems" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN IEC 62892:2019.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2020-02-22
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2022-05-22
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.

Endorsement notice
The text of the International Standard IEC 62892:2019 was approved by CENELEC as a European
Standard without any modification.

Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 61215-1 2016 Terrestrial photovoltaic (PV) modules - Design EN 61215-1 2016
qualification and type approval - Part 1: Test
requirements
IEC 61215-1-1 -  Terrestrial photovoltaic (PV) modules - Design EN 61215-1-1 -
qualification and type approval - Part 1-1: Special
requirements for testing of crystalline silicon
photovoltaic (PV) modules
IEC 61215-1-2 -  Terrestrial photovoltaic (PV) modules - Design EN 61215-1-2 -
qualification and type approval - Part 1-2: Special
requirements for testing of thin-film Cadmium
Telluride (CdTe) based photovoltaic (PV) modules
IEC 61215-1-3 -  Terrestrial photovoltaic (PV) modules - Design EN 61215-1-3 -
qualification and type approval - Part 1-3: Special
requirements for testing of thin-film amorphous
silicon based photovoltaic (PV) modules
IEC 61215-1-4 -  Terrestrial photovoltaic (PV) modules - Design EN 61215-1-4 -
qualification and type approval - Part 1-4: Special
requirements for testing of thin-film
Cu(In,GA)(S,Se) based photovoltaic (PV) modules
IEC 61215-2 2016 Terrestrial photovoltaic (PV) modules - Design EN 61215-2 2017
qualification and type approval - Part 2: Test
procedures
IEC 61730-1 -  Photovoltaic (PV) module safety qualification - Part EN IEC 61730-1 -
1: Requirements for construction
IEC 61730-2 -  Photovoltaic (PV) module safety qualification - Part EN IEC 61730-2 -
2: Requirements for testing
IEC/TS 61836 -  Solar photovoltaic energy systems - Terms, - -
definitions and symbols
IEC/TS 62915 -  Photovoltaic (PV) modules - Type approval, design - -
and safety qualification - Retesting
IEC/TS 62941 2016 Terrestrial photovoltaic (PV) modules - Quality - -
system for PV module manufacturing

IEC 62892 ®
Edition 1.0 2019-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Extended thermal cycling of PV modules – Test procedure

Cycle thermique étendu de modules PV – Procédure d'essai

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 27.160 ISBN 978-2-8322-6598-7

– 2 – IEC 62892:2019 © IEC 2019
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Sampling . 7
5 Marking and documentation . 7
6 Modifications . 8
7 Test procedure . 8
7.1 Initial evaluations . 8
7.2 Thermal cycling test . 8
7.2.1 Purpose . 8
7.2.2 Apparatus . 8
7.2.3 Procedure . 8
7.3 Final evaluations . 9
7.4 Requirements . 10
8 Reporting. 10
Annex A (normative) Calculation of the required number of thermal cycles . 11
Annex B (informative) Acceleration factors based on deployed climate . 14
Bibliography . 17

Figure A.1 – Number of equivalent cycles as a function of maximum cycle temperature
over maximum module operating temperature . 11
Figure A.2 – Survivorship plot for a Weibull distribution with a shape parameter of 6
and a survivorship probability of 95% at 500 cycles . 12
Figure B.1 – Plot of module cell temperature over the course of one day to illustrate
the maximum temperature, maximum temperature change and temperature reversal
terms . 14
Figure B.2 – Combination of factors that indicate extended thermal cycling is advised
for a specific location . 15

Table 1 – Number of required thermal cycles, N . 9
R
Table A.1 – Effect of sample size on test time . 13
Table B.1 – Cell temperature factors . 15
Table B.2 – Module and mounting specific model parameters . 16

IEC 62892:2019 © IEC 2019 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
EXTENDED THERMAL CYCLING OF PV MODULES –
TEST PROCEDURE
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62892 has been prepared by IEC technical committee 82: Solar
photovoltaic energy systems.
The text of this International Standard is based on the following documents:
FDIS Report on voting
82/1537/FDIS 82/1560/RVD
Full information on the voting for the approval of this International Standard can be found in the
report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

– 4 – IEC 62892:2019 © IEC 2019
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.

IEC 62892:2019 © IEC 2019 – 5 –
INTRODUCTION
The IEC 61215 series defines test requirements for the design qualification of flat-plate PV
modules for long-term operation in general open-air climates. IEC TS 62941 provides technical
guidance in application of the type-approval testing.
This document, IEC 62892, supplements IEC 61215 by providing an extended thermal cycling
test intended to differentiate PV modules with improved durability to thermal cycling and
evaluate modules for deployment in locations most susceptible to thermal cycling type stress.

– 6 – IEC 62892:2019 © IEC 2019
EXTENDED THERMAL CYCLING OF PV MODULES –
TEST PROCEDURE
1 Scope
This document defines a test sequence that extends the thermal cycling test of IEC 61215-2. It
is intended to differentiate PV modules with improved durability to thermal cycling and evaluate
modules for deployment in locations most susceptible to thermal cycling type stress . This
document is based on the ability for 95 % of the modules represented by the samples submitted
for this test to pass an equivalency of 500 thermal cycles, as defined in IEC 61215-2:2016,
4.11.3, with a maximum power degradation of less than 5 %. Provisions are also provided to
reduce overall test time by increasing the maximum cycle temperature and/or the number of
modules submitted for test.
The test procedure in this document was developed based on analysis of the stress on tin-lead
solder bonds on crystalline silicon solar cells in a glass superstrate type package. Changes to
lead-free solder have an effect on the acceleration factors but not enough to change the overall
results of this test. Monolithic type modules with integral cell interconnection do not suffer from
this specific type of stress but there are still electrical connections within the module, for
example between the integrated cell circuit and the module bus bars, that may be subject to
wear out from thermal cycling. Flexible modules (without glass) are not stressed in the same
way as those with glass superstrates or substrates, therefore use of the equivalency factor
employed in this document may not be applicable to these modules.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
IEC 61215-1:2016, Terrestrial photovoltaic (PV) modules – Design qualification and type
approval – Part 1: Test requirements
IEC 61215-1-1, Terrestrial photovoltaic (PV) modules – Design qualification and type approval
– Part 1-1: Special requirements for testing of crystalline silicon terrestrial photovoltaic (PV)
modules
IEC 61215-1-2, Terrestrial photovoltaic (PV) modules – Design qualification and type approval
– Part 1-2: Special requirements for testing of thin-film Cadmium Telluride (CdTe) based
photovoltaic (PV) modules
IEC 61215-1-3, Terrestrial photovoltaic (PV) modules – Design qualification and type approval
– Part 1-3: Special requirements for testing of thin-film amorphous silicon based photovoltaic
(PV) modules
IEC 61215-1-4, Terrestrial photovoltaic (PV) modules – Design qualification and type approval
– Part 1-4: Special requirements for testing of thin-film Cu(In,GA)(S,Se) based photovoltaic
(PV) modules
___________
Guidance is provided in Annex B to assess if this test is warranted for the targeted deployment location.
...