If the quality of the solar connector is not good enough, it will be a huge safety hazard. In the case of current flow, the resistance of the connector increases, which increases the temperature rise and exceeds the temperature range that the plastic shell and metal parts can withstand, causing a fire. Metal parts are the main body of the connector and the most important flow path. When operating in various environments, a stable resistance is a prerequisite to ensure the normal operation of the connector.

The contact resistance R of the connector in the usual sense. The resistance R is the resistance of the connector to the overlapped part of the metal part after insertion. If R increases abnormally, the temperature will rise, which will cause a fire in the middle of the connector.

There are three main reasons for the abnormal increase in contact resistance:

1) The installation is not in place

Inadequate installation is one of the main factors that cause R to increase. In order to ensure the flow through the connectors of each company, it is necessary to ensure that the two metal parts are incomplete contact. If the installation is not in place during the assembly process of the solar connector, the insertion of the metal parts will be abnormal.

2) PV connectors of different companies are plugged into each other

The inter-plugging phenomenon of connectors of various companies is common in power station applications, and many power station owners and component manufacturers are not aware of its hazards. Even many connector manufacturers claim that they can be inter-plugged with MC4. This is actually a big problem. Misunderstanding. UL and TÜV certification bodies have clearly stated that connectors produced by different manufacturers cannot be plugged into each other. At the same time, the Australian photovoltaic installation standard AS5033 also clearly states that connectors of two manufacturers are not allowed to be plugged into each other in a power station.

3) Failure of crimping resistance

The crimping resistance is mainly related to the crimping quality and the crimping process. The quality of crimping can be judged by the compression ratio and crimping profile. Good crimping requires a tight profile, no gaps, and a regular appearance. For the commonly used 4mm2 cable crimping, the contact resistance at the crimping point, the standard IEC2742/05 also puts forward the requirement of less than 0.2mΩ, while IEC60352-2 stipulates that the pull-out force of the crimping end should be greater than 310N.