Wet leakage current test

The wet insulation resistance test checks the PV array's electrical insulation when it is wet. It simulates rain or dew to confirm that moisture cannot reach live circuit parts, where it could cause corrosion, ground faults or a shock hazard. It follows the standard insulation test procedure, with one extra first step: spray the section under test thoroughly with water mixed with a surfactant. Make sure the module fronts, rears and edges, the junction boxes and the cables are all wet before testing. The test is mainly used for fault finding. Use it when a dry insulation test gives questionable results or when you suspect insulation faults from installation or manufacturing defects. It is good at finding damaged wiring, poorly secured junction box covers, punctures in the polymer substrate, cracked junction boxes, poorly sealed diode cases and indoor-rated connectors used outdoors. You can test the whole array, selected sections where a problem is known or suspected, or a sample portion of the array. The test carries an electric shock hazard. Follow the safety preparations for the standard insulation test and choose protective equipment suitable for wet conditions. At least two people are recommended: one wets the area and the other measures right away, because the array dries quickly and that makes results vary a lot. In the laboratory, the wet leakage test is also done as an initial and a final measurement in module stress test sequences such as the ammonia corrosion test. Leakage current rises sharply when a module is wet. However, it is not a universal indicator of degradation, because some current paths into the module do more harm than others.

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• sentence 7: support check: partial - Passages show wet leakage test in initial and final measurements of the ammonia corrosion test, but not 'in the laboratory' generally or 'such as' other sequences. -->