During operation, when current flows through a conductor, the conductor heats up due to the resistance between them. The heat generated by the fuseholder is determined to a certain extent by the formula: O = 024I2RT, where T is the time the current flows through the conductor, R is the conductor's resistance, 024 is a constant, and Q is the heat generated.
When energized, the fuse in the fuseholder's fuse element heats up due to the heat generated by the current conversion. During normal operating current or permitted overload current, the heat generated by the current gradually balances the heat dissipated by radiation through the fuse element, the housing, and the surrounding environment.
If the fuseholder's heat dissipation rate cannot keep up with the heat generation rate, this heat will gradually accumulate in the fuse element, causing it to heat up. Once the temperature reaches or exceeds the melting point of the fuse material, it will liquefy or vaporize, interrupting the current flow and protecting the circuit and personnel. The electrical function of a fuse holder is to connect the fuse in series with an electronic circuit. Generally, it requires a low resistance. When the circuit is operating normally, it acts like a single wire, ensuring long-term, reliable conduction. It should also be able to withstand certain overloads caused by current fluctuations due to power supply or external interference.
When a relatively large overcurrent appears in the circuit, the fuse in the fuse holder will trip, disconnecting the current and protecting the circuit. Therefore, two crucial operating parameters are the rated voltage and rated current. When using a fuse holder, it is important to select the appropriate fuse holder based on the circuit's current and voltage.