A fuse cutout or cut-out fuse is a combination of a fuse and a switch, used in primary overhead feeder lines and taps to protect distribution transformers from current surges and overloads. An over current caused by a fault in the transformer or customer circuit will cause the fuse to melt, disconnecting the transformer from the line. It can also be opened manually by utility linemen standing on the ground and using a long insulating stick called a “hot stick”.
Features: the rated current of the fuse is not equal to the rated current of the fuse. The rated current of the melt is selected according to the load current of the protected device.
The fuse is composed of melt, shell and bracket. The properties of a melt are determined by its material, size and shape. Melt materials can be divided into low melting point and high melting point. Materials with a low melting point, such as lead and lead alloy, are easy to fuse at a low melting point. Due to the large section size of the melt made by its high resistivity, more metal vapor is generated during the fuse. Materials with high melting point, such as copper, silver, etc., have high melting point and are not easy to fuse. However, due to their low resistivity and low melting point, the section size of the melt can be reduced. Melt shapes can be divided into filament and ribbon. Changing the shape of the section can significantly change the fuse.
The fuse has the reverse delay characteristic, that is, the overload current hour, the fuse time is long; When the overload current is high, the fusing time is short. Therefore, in a certain overload current range, when the current returns to normal, the fuse will not fuse, can continue to use. There are many different fuse curves for different types of protection.
Specification: electrical components are installed in the circuit to ensure the safe operation of the circuit.
When the circuit fault or abnormal, with the rise of the current, and the current may damage some important or expensive components of the circuit, it may burn out the circuit and even cause a fire. If the fuse is placed correctly in the circuit, the fuse will cut off the current when the abnormal current increases to a certain height and a certain time, thus protecting the safe operation of the circuit. Cut off the current to protect the safe operation of the circuit.