Four elements to avoid when using self recovering fuses (PPTC)
One: Avoid the significant mechanical stress of self recovering fuse chips
Fuses will undergo thermal expansion of the polymer itself during operation. If under certain mounting conditions, the two ends of the device chip are subjected to significant pressure, compression, distortion, bending, etc., the thermal expansion phenomenon will be limited, thereby affecting the electrical function of the device, which will cause the protective device to be unable to operate under fault conditions.
Secondly, to avoid short circuits in non packaged devices
Is there any conductive object contamination between the edge of the self-healing fuse device and the bracket when using a non encapsulated PPTC device. This non encapsulated conductive object pollutant can cause faults such as oxidation and combustion.
Thirdly, several points to pay attention to when soldering components
When wave soldering or reflow soldering is required, it is necessary to follow the prescribed operating procedures;
When it is necessary to use spot welding (resistance welding) to connect the device terminals, in order to ensure the electrical performance of the PPTC self-healing fuse, the spot welding should be controlled at a distance of more than 2mm from the edge of the device, while ensuring that the welding spatter does not touch its chip;
When manual welding is required, to avoid excessive welding temperature, the fuse should be heated to a temperature higher than its higher working temperature to control the welding time;
Fourthly, to avoid chemical contamination of PPTC self recovery fuses
Chemical pollution refers to certain types of lubricants, solvents, oils, fuels, industrial cleaning agents, colloidal volatiles, silicone oils, electrolytes, and other materials that can have a negative impact on the performance of fuses.
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