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Views: 365 Author: Site Editor Publish Time: 2022-04-29 Origin: Site
When you select electrical contacts parts for your application, will you consider the reliability of equipment? For example, if you want to get the right electrical contact parts for your switches, you must consider whether contact materials are compatible with electrical loads and environmental conditions. In fact, when you source electrical contacts for switches, there are many factors you need to consider such as the contact life cycle, heat management problems, and mechanical characteristics of metal stamping parts and so on. Of course, these questions are significant technical and metallurgical expertise. In this article, we will discuss how to choose electrical contacts for switches and what factors need to be considered.
The characteristics of switch contact materials
It is necessary to know the characteristics of switch contact materials before discussing. We know that electrical contacts are also important components of high-voltage circuit breakers, switch cabinets, isolating switches, and grounding switches, and their performance directly affects the quality and service life of these high-voltage electrical appliances. So, how to select the switch contact correctly and reasonably is very important. As a switch contact material, it should have the following characteristics.
1. It should have low resistivity and low temperature coefficient of resistance, the contact resistance should be small.
2. It has high thermal conductivity and high melting point, resistant to high temperature oxidation and chemical corrosion.
3. It has proper hardness and good processing performance.
4. It should have good abrasion resistance and arc extinguishing performance is good.
The life cycle of contact
Usually this question should be known how long the electrical contact components can last in your switches. We know that there are many factors will affect the service life of electrical contact, such as the current and voltage, the arcing etc. Usually if current is arcing across contact, the surface will be cleaned, which can keep good continuity. Otherwise, it will form contamination film or corrosion because of the surrounding environment. In addition, if the current is excessive, it will cause your application failure due to the contact weld closed and eroded.
Mechanical features
As the key components of switches, the contacts directly affect the electrical performance of the switch, and they are also an important cost factor of the switch. So, it is important to know the mechanical features of contacts, such as the problems about the dynamics of the switch, and the forces should be applied to it, and the speed that the contacts open and close etc.
Generally speaking, no matter the contacts open and close too quickly or too slowly, that will affect the service life of the device. When the contact of switch open and close too fast, the blade will bounce and cause material erosion of operating electrical contacts in the switches. But if they open and close too slow, it will affect the speed of blade, and may appear weld shut. In the past, the movable arc contacts in the switches are a finger-spring structure. This structure is complex and the spring is heated during operation to cause the reliability of its use deteriorated.
