Photovoltaic panel junction box failure

What causes a junction box to fail?

In documented module field failures the junction box is a fairly common problem [25, 26, 49, 108, 110, , , ]. The main failure modes for junction boxes include detachment (from the module backsheet), poorly sealed or closed boxes, corrosion, and arcing due to bad or degraded wiring.

Does PV module glass breakage cause defect interconnections?

This study shows a quite high rate of defect interconnections in the module and failures due to PV module glass breakage. The relative failure rate of j-box and cables (12%), burn marks on cells (10%), and encapsulant failure (9%) are comparable high. Fig. 3.2: Failure rates due to customer complaints in the first two years after delivery.

What happens if a PV module fails?

The hotspot failure mechanism is considered the most severe failure and leads to catastrophic consequences. It deteriorates all PV module components if undetected, and a PV module affected by an elevated level of hotspots cannot reverse the degradation and often requires replacement.

What are the main failure modes for junction boxes?

The main failure modes for junction boxes include detachment (from the module backsheet), poorly sealed or closed boxes, corrosion, and arcing due to bad or degraded wiring. Degradation and failure of junction box components can lead to major performance losses and safety hazards because of the high current levels passing through [25, 26, 108].

What are typical failure scenarios for wafer-based crystalline photovoltaic modules?

Fig. 3.1: Three typical failure scenarios for wafer-based crystalline photovoltaic modules are shown. Definition of the used abbreviations: LID – light-induced degradation, PID – potential induced degradation, EVA – ethylene vinyl acetate, j-box – junction box. Infant-mortality failures occur in the beginning of the working life of a PV module.

Where is the junction box located on a PV module?

The junction box is typically located on the backside of a PV module, and less commonly on the edge. It protects the connections of the strings, external wiring, and often the bypass diodes. The box is typically made from polycarbonate, and adhered to the backside of the module.