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IEC 62938
Edition 1.0 2020-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Photovoltaic (PV) modules – Non-uniform snow load testing
Modules photovoltaïques (PV) – Essais de charges de neige non uniformes
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IEC 62938
Edition 1.0 2020-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Photovoltaic (PV) modules – Non-uniform snow load testing
Modules photovoltaïques (PV) – Essais de charges de neige non uniformes
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 27.160 ISBN 978-2-8322-8074-4
– 2 – IEC 62938:2020 IEC 2020
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Sampling . 6
5 Prerequisites . 7
6 Testing . 7
6.1 General . 7
6.2 Projections of the test results . 7
6.3 Test plan . 7
7 Test procedures . 9
7.1 Visual inspection . 9
7.2 Maximum power determination . 9
7.3 Insulation test . 9
7.4 Wet leakage current test . 9
7.5 Humidity-freeze test . 9
7.6 Electroluminescence imaging . 9
7.7 Non-uniform snow load test . 9
7.7.1 Purpose . 9
7.7.2 Load specification . 9
7.7.3 Apparatus . 11
7.7.4 Procedure . 13
8 Fail criteria . 15
9 Verification of the test results . 15
10 Statistical analysis . 15
10.1 General . 15
10.2 5 % fractile value with Student's distribution . 16
10.3 Safety factor . 16
10.4 Example. 16
10.5 Quantiles of the t distribution (Student's distribution) . 16
11 Test report . 17
12 Modifications . 18
Annex A (informative) Use of determined values . 19
A.1 Estimated snow loads and use of the determined resistance . 19
A.2 Calculate the bearable loads for different angles . 19
Bibliography . 20
Figure 1 – Test plan for inhomogeneous snow load test . 8
Figure 2 – Distribution of load on the test specimen at inclination . 10
Figure 3 – Simplified cross-sectional view of module width along bottom frame . 12
Figure 4 – Test procedure for the snow load test . 14
Figure 5 – Different deflection graphs under static load . 14
Table 1 – Applicable load in relation to angle of pitch of roof . 10
Table 2 – Quantiles of the t distribution (Student's distribution) . 17
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PHOTOVOLTAIC (PV) MODULES –
NON-UNIFORM SNOW LOAD TESTING
FOREWORD
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International Standard IEC 62938 has been prepared by IEC technical committee 82: Solar
photovoltaic energy systems.
The text of this Interna
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