Three performances of waterproof connector
The three major performances of waterproof connectors are mechanical performance, electrical performance and environmental performance. Let's let the editor of Lilutong give you a detailed explanation.
1. Environmental performance:
Common environmental properties include resistance to temperature, humidity, salt spray, vibration and shock.
Temperature resistance: The current maximum working temperature of waterproof connectors is 200℃ (except for a few high-temperature special waterproof connectors), and the lowest temperature is -65℃. When the waterproof connector is working, the current generates heat at the contact point. When the waterproof connector is working, the current generates heat at the contact point, causing temperature rise. Therefore, it is generally believed that the working temperature should be equal to the sum of the ambient temperature and the temperature rise of the contact. In some specifications, the maximum temperature rise allowed by the waterproof connector under the rated working current is clearly specified.
Salt spray resistance: When the waterproof connector works in an environment containing moisture and salt, the surface treatment layer of its metal structural parts and contacts may produce galvanic corrosion, which affects the physical and electrical performance of the waterproof connector. In order to evaluate the ability of the electrical waterproof connector to withstand this environment, a salt spray test is specified. It hangs the waterproof connector in a temperature-controlled test box, sprays out a sodium chloride solution with a specified concentration with compressed air to form a salt spray atmosphere, and its exposure time is specified by the product specification, at least 48 hours.
Vibration and shock: Vibration and shock resistance are important properties of electrical waterproof connectors. They are particularly important in special application environments such as aviation and aerospace, railway and road transportation. It is used to test the mechanical structure of electrical waterproof connectors. An important indicator of contact reliability. There are clear regulations in the relevant test methods. In the shock test, the peak acceleration, duration and shock pulse waveform, as well as the interruption time of electrical continuity should be specified.
The intrusion of moisture resistance will affect the insulation performance of the connection h and rust metal parts. Constant humidity test conditions are relative humidity 90%~95% (according to product specifications, up to 98%) temperature +40±20℃, test time is according to product regulations, at least 96 hours. The alternating damp heat test is more stringent.
2. Mechanical properties:
As far as the connection function is concerned, the insertion force is an important mechanical performance. Insertion and extraction force is divided into insertion force and extraction force (extraction force is also called separation force), the requirements of the two are different. The insertion force should be small (there are structures with low insertion force LIF and no insertion force ZIF), and if the separation force is too small, it will affect the reliability of contact. Another important mechanical property is the mechanical life of the waterproof connector. Mechanical life is actually a durability indicator, which is called mechanical operation in the national standard GB5095. It takes one insertion and one unplugging as a cycle, and whether the waterproof connector can normally complete its connection function (such as contact resistance value) after the specified plug-in cycle is used as the judgment basis.
The plug-in force and mechanical life of the waterproof connector are related to the contact structure (positive pressure), the coating quality of the contact part (the sliding friction coefficient) and the dimensional accuracy of the contact arrangement (alignment).
3. Electrical performance
The main electrical properties of waterproof connectors include contact resistance, insulation resistance, and dielectric strength.
①Insulation resistance is a measure of the insulation performance between the contacts of the electrical waterproof connector and between the contacts and the shell. Its magnitude ranges from hundreds of megohms to several thousand megohms.
② Dielectric strength, or withstand voltage, dielectric withstand voltage, is the ability to withstand the rated test voltage between the contacts of the waterproof connector or between the contact and the shell.
③The electrical waterproof connector with high contact resistance should have low and stable contact resistance. The contact resistance of the waterproof connector ranges from a few milliohms to tens of milliohms.