Whether the fuse operates normally requires certain conditions. The following small series explains the working environment and conditions required for the normal operation of the self-recovery fuse.
The necessary conditions for normal operation of self-recovery fuse are explained as follows.
(1) When the normal working current is running at 25℃, the current rating of self-recovery fuse is usually reduced by 25% to avoid harmful fusing. Most traditional fuses use materials with low melting temperature. Therefore, this fuse is very sensitive to the change of ambient temperature. For example, a self-recovery fuse with a current rating of 10A is generally not recommended to operate at a current above 25℃;
(2) The voltage rating of fuse must be equal to or greater than the effective circuit voltage. The standard voltage rating series is generally 32V, 125 V, 250 V and 600 V;
(3) The resistance of the resistance fuse is not important in the whole circuit. Since the resistance of fuses with amperage less than one is only a few ohms, this problem should be considered when using fuses in low-voltage circuits. Most fuses are made of materials with positive temperature coefficient, so there are cold resistance and hot resistance.
(4) Current carrying capacity of self-recovery fuse. The experiment was carried out at 25℃ and was affected by the change of ambient temperature. The higher the temperature, the higher the working temperature and the shorter the life of the fuse. On the contrary, running at lower temperature will prolong the life of fuse.
(5) Fuse rated capacity is also called breaking capacity. Fuse rated capacity is the maximum allowable current at which the fuse is blown at rated voltage. In case of short circuit, instantaneous overload current larger than normal working current will pass through the fuse many times. Operation requires that the fuse be kept in a complete state (without bursting or breaking) and short circuit be eliminated;
