Factors affecting the service life of the fuse2020-05-18
What are some factors that affect the service life of the fuse, help everyone to pay more attention to these aspects in the future, and better protect the fuse:
1. Working environment temperature:
Excessive ambient temperature is detrimental to the life of the fuse holder. Ordinary fuse holder. When the temperature is about 160 degrees, tin begins to diffuse into the metal wire; the temperature at which the melt can start to oxidize more violently is about 200 degrees. With the oxidation of the fuse from outside to inside, multiple diffusion, thermal stress fatigue, etc., the life of the fuse will gradually shorten. Therefore, it is recommended that the delayed fuse holder should not work for more than 150 ℃ for a long time, and the normal working fuse holder should not work for more than 175 ~ 225 ℃ for a long time.
2. Pulse current:
Pulse shock will cause thermal cycling, which will cause the fuse to diffuse, oxidize, thermal stress, etc., or even accelerate. The fuse holder will gradually age with increasing pulse energy and frequency. The impact resistance life of the fuse holder depends on the pulsed I2t as a percentage of the fuse itself I2t; usually, it should be less than 20%, so that the fuse can withstand more than 100,000 shocks.
Pipe clamps in contact with the fuse holder, and the length and cross-sectional area of connecting wires. The contact resistance between the fuse holder and the pipe clamp is large, which is detrimental to life. The UL standard stipulates that the contact resistance between the fuse and the pipe clamp during the test is less than 3mΩ. When the contact resistance is large, the tube clamp does not dissipate heat but generates heat and transmits it to the fuse.