Power tools have the advantages of convenient use, high speed, small size, light weight, large starting torque, and strong overload capacity, and are widely used in industries such as industry, construction, decoration, auto repair, and gardening.  It is understood that China currently consumes about 8 million various types of power tools each year, of which nearly 3 million are imported from abroad, and the trend is growing.

When purchasing, choose electric tools produced by formal manufacturers. Each tool should be accompanied by a certificate of quality and instructions. It is recommended to run the electric tool without load when purchasing handheld tools, and observe the sparks at the brush and the noise of the tool. Generally, tools with stable quality have small sparks when running without load, and the sound is uniform without noise. If a power meter is available, it can monitor the power of handheld tools.  Generally, the no-load power does not exceed 90% of the rated power. And priority should be given to using Class II tools (with the symbol "H" printed on the nameplate) and Class III tools (safety extra-low voltage power supply).  Class I tools are not recommended because due to their structural design characteristics, they have high requirements for external protection and are prone to causing electric shock accidents.

When using Class III tools, they must be used together with a safety isolation transformer, and attention must be paid to the matching of the tool's rated voltage with the output voltage of the safety isolation transformer to prevent overvoltage and damage to the purchased tools.

The safety of using Class I tools not only depends on the design and manufacturing of the tools, but also depends on the entire grounding system and overcurrent protection system. Currently, the maintenance of the grounding system in some factories and construction projects is not perfect, making it difficult to maintain a small grounding resistance for a long time.  Therefore, it is very difficult to prevent electric shock accidents when using Class I power tools. Therefore, when using Class I power tools, especially in hazardous workplaces, it is necessary to add a residual current action protector. From a safety perspective, Class I tools should not be used in open workplaces.  In addition, the power cord of Class I tools is not allowed to be arbitrarily extended or disassembled to prevent the protection grounding from being connected to the phase line by mistake, which may cause accidents.

<p style="text-indent: 2em;>At the same time, operators should carefully read the instructions before using power tools to understand the operating procedures and correct usage methods of the tools to avoid misuse. With the revision of the standards for power tools, there are strict requirements for the content of the instructions and strong operability. Therefore, it is important to carefully read the instructions, strictly follow the instructions for operation and troubleshooting, and choose the appropriate power tools according to different functions.  It is prohibited to modify and use the tools without authorization.