Blog

18
May 2021

FACTORY FINDINGS

PV MODULE INSPECTION

NON-CONFORMITIES CAUSED BY IMPROPER OPERATION AND MAINTENANCE

 

–  Is the right BOM material used?

On regular basis, STS captures operator’s errors leading to mistakes in BOM components used for the order. Using the wrong material may have very serious consequences not only in terms of quality control, but also in view of the new supply chain requirements that we are observing in the industry. Continuous BOM control at every shift is becoming a necessity.

– Why is this string so dark?

The image above does not show a very usual EL defect pattern. In fact, it is not a module defect. This pattern is the signature of bad contact of the EL tool. Every so often (abut one every 20 modules), the oxidized electrode was not properly contacting the string. Less current was flowing through the affected cells, rendering the image difficult to read. STS inspectors not only verify the quality of the modules, but also the calibration, measurement methods and qualification of the operators.

– Loose installation of the junction box

When not enough silicone is used to affix the junction box, the junction may become loose, creating all sorts of safety concerns. Operator’s training and qualification is key in delivering high-quality, safe and high-durability modules.

– Calibration mistakes more common during night shifts

We mentioned before that we find twice on average as many non-conformities in night shifts than in day shifts. For instance, this month again, we find that the attention of operators seems to be dropping at night, leading to more calibration mistakes during maximum power measurements.

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