Blog

09
Apr 2021

FACTORY FINDINGS

– PV MODULE & ENERGY STORAGE INSPECTION

NON-CONFORMITIES CAUSED BY IMPROPER OPERATION AND MAINTENANCE

EL defects and visual defects are commonly seen in our PV module inspections, including frame gaps, sharp edges, broken corners, cracks, ribbon mis-alignments, scratches and corrosion, glue bubbles, cell dirt, EVA wrinkles, etc.

When a defect is repeatedly observed, STS requires a root-cause analysis. Recently, we triggered a root-cause analysis in the framing step, where we observed gaps exceeding specification. We found that the run distance of the screw mandrel adjusting the frame alignment, the position of fixture holding the frame and the torque force applied during assembly could all potentially contribute to an unacceptable frame gap. These frame gaps can be sharp and potentially cause injury to installers or any end-user across the globe.

- Uneven Distance Between the Cell and The Frame in a PV Module

The distance of the inner circuitry to the edge of the module can also cause a safety concern. Here is an example of a finished module with uneven distance between the cell and the frame. After the root-cause was identified, STS requested corrective action to prevent this non-conformity in subsequent manufacturing.

ENERGY STORAGE INSPECTION

– Factory Acceptance Tests

We continuously catch some non-conformities at factory acceptance tests. To illustrate with a couple of examples, we have recently seen failed opening door protection, non-standard operation for the remote and HMI control test, failed grounding impedance, failed insulation withstand voltage, battery module operating temperature and test ambient temperature not in conformity with the standard requirement, etc. STS recommends 100% FAT witness for energy storage systems.

– Pack Assembly Line

We also witnessed some mis-practices in the pack assembly line: wrong voltage test procedure used, inaccurate static voltage sorting range on pack line, improper pack capacity test, damaged pack at shipping/installation into racks, no dustproof plug on the packs, etc.

Hire an accredited inspection body to have a standard QA/QC inspection in the factory to help you catch these mis-practices before any non-conformities jeopardize your project performance.

It is World Quality Day on Nov.10, with the theme of “Quality Conscience: Doing the Right Thing”.For STS, every day is World Quality Day!
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