1) When used, hand-held power tools often have large vibrations, which can easily cause damage to the insulation or structural damage and cause electric shock.
2) The power cord of the hand-held power tool is easy to wear at the lead-out part. Once the core wire conductor is exposed or touches the metal shell, it may cause electric shock.
3) The grounding (zero connection) protection of the metal casing fails to really work. If there is a protective wiring at the plug, no protective wire is connected to the socket, or the protective wire itself is broken or disconnected from the terminal, it may easily cause electric shock.
4) When the tool is disabled, the power supply is not cut off or the mobile electrical equipment is not cut off when moving. The power cord is cut or crushed to cause electric shock.
5) There is no defect in the equipment itself. When using it, the condition of the construction site is unknown, causing the tool to touch the live wire and causing electric shock. For example, perforating the wall, punching into the wiring laid in the dark, or punching the floor slab to the wire laid in the hole of the board, it is easy to cause electric shock.
6) These tools or equipment are often held very tightly during use. Once an electric shock occurs, they may not be able to get rid of it, and the consequences are more serious.