How fuse cutout work

When used, the windproof fuse is connected in series with the circuit it protects. When the circuit is overloaded or short-circuited, if the current through the melt reaches or exceeds a certain value, the heat generated on the melt will increase its temperature. , when it reaches the melting point of the melt (200~300℃), the melt will melt by itself, cutting off the fault current and playing a protective role.

1. Main forms of current protection for electrical equipment

Overload delay protection and short circuit instantaneous protection.

Overload generally refers to overcurrent below 10 times the rated current.

A short circuit refers to an overcurrent exceeding 10 times the rated current.

2. Precautions for using windproof fuses

Overload protection and short-circuit protection are not only different in current multiples, but are actually very different. From the perspective of characteristics, overload requires inverse time protection characteristics, and short circuit requires instantaneous protection characteristics.

From the perspective of parameters, overload requires a small melting coefficient and a large heating time constant, while a short circuit requires a large current limiting coefficient, a small heating time constant, a high breaking capacity and a low overvoltage.

From the working principle, the physical process of overload action is mainly the thermal melting process, while the short circuit is mainly the arc extinguishing process.