IEC EN 61701 Photovoltaic Modules - Salt Mist Corrosion Test

EUROLAB, with its state-of-the-art accredited laboratories and expert team, offers precise and rapid testing services within the scope of IEC EN 61701 testing. IEC EN 61701 describes a series of tests useful for determining the resistance of different PV modules to corrosion from salt vapor containing Cl (NaCl, MgCl2, etc.).

All tests in the series are fully described in IEC 61215‑2, IEC 62108, IEC 61730‑2 and IEC 60068‑2‑52. The bypass diode functionality test in this standard has been modified from its description in IEC 61215‑2. These have been combined in this standard to provide tools for assessing possible failures of PV modules when operating in wet atmospheres with high concentrations of dissolved salt (NaCl). Depending on the particular nature of the surrounding atmosphere to which the module is exposed during actual operation, various test methods may be applied, as defined in IEC 60068-2-52.

The main technical changes compared to the previous edition are as follows:

• The scope has been updated to better reflect the applicability of the Standard;
• Test methods and requirements have been summarized and harmonized with new editions of IEC 61215-1, IEC 61215-2 and IEC 61730-2. References to crystalline silicon and thin film technologies have been eliminated. The old figure 2 in the thin film test sequence has been eliminated;
• Salt fog testing references have been updated to comply with changes in IEC 60068‑2‑52;
• A normative annex has been added to provide guidance on which of the test methods in IEC 60068-2-52 can be applied to different applications.

After stabilization, tests are performed to characterize the PV module and verify that it is operational before exposure to salt fog. After exposure, samples are cleaned and allowed to cure. This sequence is then repeated and the functional test of the bypass diode is performed.

After salt fog testing, all samples will be washed to remove adhering salt using running tap water (not artificially pressurized) for a maximum of 5 minutes per square meter area of ​​the sample. Once the washing is finished, distilled or demineralized water will be used to rinse the samples, then dry them completely at room temperature. The use of fans is allowed to accelerate drying. Caution is advised when blowing air to speed drying, as excessive airflow can cause moisture to penetrate areas it would not normally reach.

The temperature of the water used for washing should not exceed 35°C. Wiping samples with cloth, gauze or other material should be avoided during cleaning or drying. Once dry, recovery time should be minimized and the applicable test sequence should be continued as soon as possible to prevent further damage caused by salt deposits.

This test is performed following salt mist exposure only if the module contains bypass or blocking diodes. Its purpose is to verify that the bypass or blocking diodes of the test samples remain functional.

EUROLAB assists manufacturers with IEC EN 61701 test compliance. Our test experts, with their professional working mission and principles, provide you, our manufacturers and suppliers, the best service and controlled testing process in our laboratories. Thanks to these services, businesses receive more effective, high-performance and quality testing services and provide safe, fast and uninterrupted service to their customers.