Working theory of Fuse Cutout

In normal operation the fuse link is tightened to form the closed position, when fault current occurs, the fuse link melts down and electric arc produce, the arc extinguishing tube is heated and explosive gas happens. This results in high pressure inside the tube and makes tube to be disconnected from the contacts. The strength of the contact is released once the fuse elements melt down. The cutout now is in OFF position, the operator needs to switch off the current. Use an insulated operating rod to pull, the moving contact can be pulled off.