IEC 61701:2011 pdf free download – Salt mist corrosion testing of photovoltaic (PV) modules
1scope and object
Photovoltaic(PV) modules are electrical devices intended for continuous outdoor exposureduring their lifetime.Highly corrosive wet atmospheres,such as marine environments, couldeventually degrade some of the PV module components (corrosion of metallic parts,deterioration of the properties of some non-metallic materials – such as protective coatingsand plastics – by assimilation of salts,etc.) causing permanent damages that could impairtheir functioning.Temporary corrosive atmospheres are also present in places where salt isused in winter periods to melt ice formations on streets and roads.
This Standard describes test sequences useful to determine the resistance of different Pvmodules to corrosion from salt mist containing Clr(NaCI,MgCl, etc.). All tests included in thesequences，except the bypass diode functionality test， are fully described in EC 61215,IEC 61646,IEC 62108, IEC 61730-2 and lEC 60068-2-52.They are combined in this Standardto provide means to evaluate possible faults caused in PV modules when operating under wetatmospheres having high concentration of dissolved salt(NaCl). Depending on the specificnature of the surrounding atmosphere to which the module is exposed in real operationseveral testing severities can be applied, as defined in IEC 60068-2-52.For example severity(1) is intended to be used for PV modules used in a marine environment, or in close proximityto the sea. Severities (3) to (6) are intended for PV modules operating in locations wherethere could be a change between salt-laden and dry atmospheres,for examples in placeswhere salt is used to melt ice formations. Severity (2) is not suitable for PV modules astesting conditions are too weak (this severity is originally intended for products exposed tocorrosive environments from time to time that are normally protected by an enclosure) andshould be avoided when applying this Standard.
This Standard can be applied to both flat plate PV modules and concentrator PV modules andassemblies.
3Samples
Three identical samples of the model of PV module or assembly of interest shall be subjectedto any of the testing sequences included in Figures 1, 2 or 3, depending on the PV technologyconsidered,namely crystalline silicon,thin-film or concentrator photovoltaic (cPV)respectively.As the figures indicate one of these samples should be used as a control. Thecontrol sample should be used as a check every time the test samples are measured toevaluate the effect of the salt mist test.
ln the case of CPV different situations for choosing the sample may occur. For non-field-adjustable focus-point CPV systems or modules，3 modules are required to complete thetesting sequence included in Figure 3. For field-adjustable focus-point CPV systems orassemblies，3 receivers (including secondary optics sections，if applicable) and 3 primaryoptics sections are required to complete the testing sequence included in Figure 3. Acomplete description of the different types and components of CPV modules and assembliescan be found in iEC62108.
lf a full-size sample is too large to fit into the environmental chambers required for the saltmist test then a smaller representative sample may be specially designed and manufacturedfor this test. The representative sample should be carefully designed so that it can revealsimilar failure mechanisms as the’ full-size one, and the fabrication process of therepresentative sample should be as identical as possible to the process of the full-size ones.The fact that the test has been made on representative samples and not on the full-sizesamples has to be indicated and reported in the test report under item g), see Clause 11.
lf the PV module is provided with means for grounding then they constitute a part of the testsample.
4Test procedures
4.1 General
All tests included in Figures 1, 2 or 3, except the bypass diode functionality test, are fullydescribed (including purpose, apparatus，procedure and requirements) in the EC Standardsfrom where the specific tests are taken (see notes in the Figures).Tests included in Figures1, 2 or 3 shall be performed in the specified order. In the case of CPV if some test proceduresincluded in this’Standard are not applicable to a specific design configuration，themanufacturer should discuss this with the testing agency to develop a comparable testprogram，based on the principles described in this Standard.Any changes and deviationsshall be recorded and reported in detail, as required in Clause 11, item l).