The terminal is very common, so more consideration should be given in the design. For example, in the power industry, the requirements for the terminal include: the edges and corners of the product shell, the burr in the hardware, the connection strength of each component, and even the stability of the product under the conditions of movement.
The protection requirements for the shell of terminals are mainly the provisions of JB / T 9568-2000 on the protection level, which is mainly divided into two types, one is the protection level of solid foreign matters, the other is the harm of water to equipment and products. At the same time, for the insulation coordination of the terminal, it is often necessary to consider the material selection, working voltage and environmental pollution level to determine the electrical clearance and creepage distance, so as to protect the safety of workers and products.
At the same time, the insulation of the product will not be damaged under overvoltage; in addition, the requirement of leakage tracking index should be taken into account. During the use of the product, due to the effect of electric field and electrolyte on the surface of solid insulating material, a conductive path will be formed, so that the insulation performance of the shell insulation material will be reduced and the safety of the product will be affected.
Also consider the material deformation, because the thermoplastic material is mainly the temperature rise and contact resistance of the terminal in the work. The high temperature caused by the thermoplastic material makes the shell deform and soften, thus making the electric short circuit and causing serious accidents. Therefore, it is very important to select the material of the current carrying parts of the terminal.
It is required that during the structural design of the terminal, the operating element shall not be charged, and the terminal connected with the internal part shall not be accessible. This is mainly the requirement for the reliability of screw torque, and the screw and conductor of accessible terminal shall be prevented from accidental loosening and short circuit.