Cross-mating, which refers to the plugging of connectors from different manufacturers (between modules to optimizers/microinverters, modules to field-connectors, optimizers to field connectors or field connectors to the BOS system) is one of the most common PV wiring mistakes. In fact, the EU-funded Solar Bankability Project’s Failure Modes and Effects Analysis (FMEA), which sourced data from over 1 million documented insurance claims, showed that “different kinds of connectors” (cross-mating) had the highest risk potential in PV installations, and it wasn’t even close. The reason for the risk here is connectors from different manufacturers have different dimensions, materials and engineering tolerance. The slight variation between different manufacturers can result in higher contact resistance (heat), water intrusion or unexpected deterioration of contact or plastic parts. “Each connector has different critical dimensions and even using the most precise calipers to copy connectors still doesn’t guarantee a secure connection,” says Dean Solon, CEO and founder of Shoals. “Secondly, these connector manufacturers do not always utilize the same metals or procure their contact termi...