IEC TS 63397:2022

IEC TS 63397 ®
Edition 1.0 2022-12
TECHNICAL
SPECIFICATION
colour
inside
Photovoltaic (PV) modules – Qualifying guidelines for increased hail resistance
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Secretariat Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform IEC Products & Services Portal - products.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews. With a subscription you will always have
committee, …). It also gives information on projects, replaced access to up to date content tailored to your needs.
and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 300 terminological entries in English
details all new publications released. Available online and once
and French, with equivalent terms in 19 additional languages.
a month by email.
Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc

If you wish to give us your feedback on this publication or need
further assistance, please contact the Customer Service
Centre: sales@iec.ch.
IEC TS 63397 ®
Edition 1.0 2022-12
TECHNICAL
SPECIFICATION
colour
inside
Photovoltaic (PV) modules – Qualifying guidelines for increased hail resistance

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 27.160 ISBN 978-2-8322-6194-1

– 2 – IEC TS 63397:2022 © IEC 2022
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Number and selection of test samples . 8
5 Test procedures . 8
5.1 General . 8
5.2 Visual inspection (MQT 01) . 8
5.3 Initial stabilization (MQT 19.1) . 8
5.4 Performance at STC (MQT 06.1) . 8
5.5 Performance at low irradiance (MQT 07) . 9
5.6 Insulation test (MQT 03) . 9
5.7 Wet leakage current test (MQT 15) . 9
5.8 Electroluminescence imaging . 9
5.9 Damp heat test (MQT 13) . 9
5.10 Hail test (HMQT 17) . 9
5.10.1 General . 9
5.10.2 Purpose . 9
5.10.3 Apparatus . 9
5.10.4 Procedure . 11
5.10.5 Final measurement . 12
5.10.6 Requirements . 12
5.11 Cyclic (dynamic) mechanical load test (MQT 20) . 13
5.12 Thermal cycling test (MQT 11) . 13
5.13 Humidity-freeze test (MQT 12) . 14
5.14 Final stabilization test (MQT 19.2) . 14
5.15 Requirements . 14
6 Report . 16
Annex A (informative) Hail maps . 18
Bibliography . 19

Figure 1 – Hail test equipment . 10
Figure 2 – Hail test example impact locations for wafer/cell based technologies and for
monolithic thin film technologies . 13
Figure 3 – Test flow . 15
Figure A.1 – Hailstorm map: Global . 18

Table 1 – Ice-ball masses and kinetic energy . 11
Table 2 – Impact locations . 12
Table 3 – Example of power loss reporting. 16
Table 4 – Schematic example of electroluminescence images prior and post stress
tests . 17

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PHOTOVOLTAIC (PV) MODULES – QUALIFYING
GUIDELINES FOR INCREASED HAIL RESISTANCE

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects because each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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.
IEC TS 63397 has been prepared by IEC technical committee 82: Solar photovoltaic energy
systems. It is a Technical Specification.
The text of this Technical Specification is based on the following documents:
Draft Report on voting
82/2062/DTS 82/2090/RVDTS
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this Technical Specification is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.

– 4 – IEC TS 63397:2022 © IEC 2022
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under 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 document 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.

The contents of the corrigendum 1 (2023-07) have been included in this copy.

INTRODUCTION
The hail test (MQT 17) of IEC 61215-2:2021, 4.17 examines PV modules for minimum hail
resistance by using spherical ice balls of a minimum diameter of 25 mm, or optionally larger.
The requirements after the test, as specified in IEC 61215-2, are:
a) no intermittent open-circuit fault detected during the test,
b) no evidence of major visual defects,
c) wet leakage current meeting the same requirements as for the initial measurements and the
power loss requirement of (Gate No. 2) IEC 61215-1:2021, 7.2.3.
The hail test (MQT 17) may cause visible damage detectable by MQT 01 as well as invisible
internal damage not detectable by MQT 01. Such invisible damage may also only be detected
by Gate No. 2 (power loss measurement after stress tests) if the damage is relatively large.
The IEC 61215 series [1] lays down requirements for the design qualification and type approval
of terrestrial photovoltaic modules suitable for long-term operation in open-air climates. It is
however not written with the intent to detect medium to long term performance losses caused
by hail to internal parts not visible to the naked eye. Such internal damages may be micro-cracks
of cells which over time can be propagated by other mechanical and thermo-mechanical
environmental stresses not addressed by the test flow of IEC 61215-1:2021, Figure 2.
The hail test (MQT 17) of IEC 61215-2:2021, 4.17 is sufficient for the generic design
qualification and type approval for applications
...