Why does the connector cause bad phenomena

Regardless of the product being manufactured, as long as the quality of the product is not enough, it will cause a variety of problems, and even more serious threats to the personal safety of people when using the product. For example, the connectors and junction boxes in photovoltaic modules are small and precise small parts, but these two small parts will be a huge safety hazard if they are not in quality! Up to now, there have been too many fires in our country due to overheating of connectors, which has brought huge economic losses to the power station.

After investigation, the root cause of the fire is that the resistance of the connector increases under the condition of the flow, which causes the temperature rise to increase and exceed the temperature range that the plastic casing and the metal parts can withstand, thereby causing a fire. Therefore, the failure of the connector and the fire caused by the combination of the plastic casing and the metal parts, the following three failure analysis may help you understand the knowledge.

the failure analysis of the resistor Rco

The resistor Rco is the resistance of the connector to the overlapped part of the metal piece. If the Rco is abnormally increased, the temperature rises, which may cause a fire in the middle of the connector. The crimping resistor Rcr is mainly related to the crimping quality and the crimping process. We can judge the quality of the crimping by the compression ratio and the crimping profile. A good crimping requirement requires that the profile be tight without gaps and that the shape is regular. For the commonly used 4mm2 cable crimping, the contact resistance at the crimping point, the standard IEC2742/05 also proposes a requirement of less than 0.2mΩ, while the IEC60352-2 specifies that the pull-out force of the crimping end is greater than 310N.

the failure analysis caused by sealing performance

Because the connectors in the PV modules are outdoors, there are strict requirements for sealing performance. For example, some connectors have achieved IP65 and IP68 protection levels. Since the connector is mated to the cable, the choice of cable becomes very important when it comes to sealing. In general, different connector models will correspond to different cable ODs, the purpose is to ensure sealing performance. In order to verify the compatibility of the cable, the connector should be tested after it is assembled, such as IP test, wet insulation test and withstand voltage test. In another case, it is difficult to ensure the sealing property of the connector. Therefore, in outdoor applications, it is possible to inject water into the dust, thereby damaging the insulation performance and causing a fire.

the failure analysis caused by insulation materials

In the manufacturing process, the choice of insulation material directly determines the quality of the connector. A good connector needs to select a suitable insulation material, and whether it is suitable is mainly determined by the connector use requirements. For example, weather resistance, heat resistance, flame retardancy, mechanical properties, insulation properties of materials, etc., and the choice of connector insulation materials in photovoltaic modules is the result of comprehensive consideration of these properties. Some manufacturers use recycled materials to reduce the cost of product materials, but they increase the probability of failure of the product at the use end, so choosing the right material can reduce the probability of fire at higher temperature rise. Therefore, customers should eliminate the use of recycled materials for manufacturing when selecting the connector manufacturers.

Yeahui is a connector supplier with 11 years of experience in developing high quality connectors and wiring harnesses. wo have many types of products, including obd connectors, circular connectors, agricultural connectors and so on.We can meet the requirements of various customers. Feel free to learn more about connectors or buy our connectors,looking forward to your message.

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