Screw-type fuse protector (RL): screw-type fuse protector mainly consists of porcelain cap, fusing tube, porcelain cover, upper terminal, lower terminal and pedestal etc.

In the fusing of RL1 series of screw-type fuse protectors, besides the fuse wire, the quartz sand is also filled up around the fuse wire for extinguishing electric arc. There is a small red dot on the top of fusing tube, and the red dot will fall off automatically after fuse wire fuses, which shows that fuse wire is already fused. When using, insert one end of fusing tube with red dot into porcelain cap with screw thread on it, and screw up the nut together with fusing tube into porcelain pedestal, then fuse wire will connect circuit.

During installation, connect the connecting line of electric-equipment to the terminal connected with metal screw thread shell and connect the power line to the lower terminal on pedestal. In this way, in changing fuse wire, after the nut is screwed, the screw thread shell will not be electrified.