We will definitely use power tools in our lives, and they have brought a lot of convenience to our lives. With the development of science and technology, power tools have been greatly improved in terms of safety in use and work efficiency. Power tools are mainly divided into Portable power tools Electric Wood Circular Saw, cutting machine
, grinding power tools, assembly power tools and railway power tools. Common power tools include electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, and so on.
According to GB3787 "Safety technical regulations for the management, use, inspection and maintenance of hand-held power tools", hand-held power tools are divided into three categories:
Classification of hand-held power tools:
1. Class I tools. In addition to basic insulation, the protection against electric shock also adopts zero-connection protection; Class I tools are metal shells, and the power supply part has insulating properties, which is suitable for dry places;
2. Class II tools. The tool itself has double insulation or reinforced insulation, and measures such as protective grounding are not taken; II This type of tool not only has insulating properties in the power supply part, but also the shell is an insulator, that is, it has double insulating properties. The tool nameplate is marked with the word "return", which is suitable for relatively humid workplaces;
3. Class III tools. Powered by safety extra-low voltage power supply, no voltage higher than safety extra-low voltage is generated inside the tool; III tool is powered by safety extra-low voltage power supply, which is suitable for working in particularly humid workplaces and in metal containers.