Why is there a screw hole under the second hole of the bull?

The fixing screws used for the Bull plug strip are special-shaped screwdriver slots, which are different from the common slots and cross slots. To open the bull socket, there must be two screw holes on the back of the power supply. Use the screw to open it, and you will see the terminal block. You can open the bull socket, and the bull socket does not want people to open it casually, so the screws are specially made. Ordinary screws cannot be twisted, so special screws are needed. Its head is like a fork. Same, so the suggestion is not to open the bull socket casually. If you can't see the screws, it means that there is a cover on the socket. This cover is stuck on the socket. You only need to dig around with your hands to remove it easily. If it is very tight, use an electric pen to pry it off. Once it is removed, you can see the screws inside. If you need to open the socket, you can unscrew the screws again.

Extended information: There are three exposed wiring holes on the bull socket five-hole socket, which identify the L live wire, N neutral wire, and E ground wire respectively. Remove the insulation about 2 centimeters from the end of the power cord, exposing the copper wire. The two wire ends are twisted together. If the wire end is too long, some should be cut off. Connect the live wire (L) of the socket and the live wire of the circuit to the same switch terminal. hole, the neutral line is merged into the N hole, and the ground wire is inserted into the ground hole (it is an icon, that is, the one with 1 vertical on the top and 3 horizontal on the bottom). In fact, for ordinary bull sockets, wiring is very simple. Unscrew the cover at the back of the socket, peel off the insulation layer from the three ends of the wire, use a cross to connect the wire ends to the copper connector inside the socket, and use a screwdriver to Tighten it, and then cover it with the cover and it's ok. The three-hole socket is connected to the ground wire, the right side is connected to the phase wire, and the left side is connected to the neutral wire. The two-pin socket should also be the same. To install the wall switch socket securely, its connectors need to be tightened.