Hand-held electric tools used by electricians are used in a harsh environment, which are constantly moving, vibrating and noisy. The power line is vulnerable to damage due to external forces such as drag, friction or mechanical extrusion, which will damage the insulation strength and cause personal injury and death due to electric shock. In order to prevent accidents, hand-held electric tools should be selected correctly.

　　Select method

　　1. Select qualified products with "3C" certification.

　　2. Class II products should be selected for general occasions. This type of equipment has double insulation and is relatively safe to use.

　　3. Class II or III products shall be selected when working in wet places or metal structures and other places with good conductivity.

　　4. Class III products shall be selected when working in metal containers, pipes, boilers and other narrow places.

　　5. If it is really necessary to use Class I products, other necessary safety measures shall be taken according to the safety requirements, such as installing leakage protector, safety isolation transformer, etc.

　　usage method

　　1. Before use, it should be carefully checked to ensure that the appearance is free of damage, the switch action is flexible and free of jamming, and the power lead and the shell of the electric tool should be intact. The insulation resistance between winding and shell measured with a 500V megohmmeter shall not be less than 0.5 megohm. See the attached table for the insulation resistance value.

　　2. Hand-held electric tools with metal shell shall have reliable protective grounding wire. The power lead is a multi-core flexible rubber sheathed cable, and the two ends of its grounding protection wire should be firmly connected.

　　3. Hand-held electric tools should be used by full-time personnel with certain professional knowledge. Relevant safety operation regulations shall be strictly observed during use.

　　4. Before use, check whether relevant electrical protection devices and mechanical protection devices are in good condition. Its application should be normal.

　　Also pay attention to whether the rotating part rotates flexibly without jamming.

　　5. When using Class I hand-held electric tools, the user must wear protective equipment that meets the requirements and set up qualified protective equipment. Take corresponding safety protection measures against electric shock according to regulations, such as installing leakage protector in the power circuit, or wearing insulating gloves, insulating shoes or standing on insulating mat.

　　When Class II hand-held electric tools are used in humid and narrow places, leakage switches shall be installed. The working current of the electric switch is less than 1.5mA, and the action time is less than or equal to 0.1s. The leakage switch shall be placed in the container and supervised by a specially-assigned person.

　　6. Occupational hazards of using hand-held electric tools. The arm vibration disease caused by long-term manual vibration operation was listed as one of the statutory occupational diseases in China as early as 1957, also known as local vibration disease, and typically manifested as paroxysmal white fingers.

　　Hand-held electric tools, especially those with rotating parts with unbalanced mass inside, such as tools with crank connecting rod piston impact device and tools with eccentric device (such as electric hammer, electric pick, etc.), will produce large vibration when moving. When operating these tools, the vibration will be transmitted to the operator's hands, wrists and shoulders. With the wide application of electric tools, people pay more and more attention to their vibration hazards.

　　Common measures for occupational disease prevention include: carefully maintain and maintain tools according to the requirements of the manufacturer's instructions; When different tools can be rotated, use the operation method that produces lower vibration as much as possible; The tool shall be prevented from generating cold gas and liquid around the operator's hand; If possible, heat the operating handle of the tool under cold conditions; Avoid using tools with high pressure on the skin due to the handle shape in the contact area; When optional, tools requiring small contact pressure (holding force and feeding force) shall be selected; Use damping gloves; Wear gloves during operation to avoid hearing damage. [3] Select and use editing

　　Hand-held electric tools used by electricians are used in a harsh environment, which are constantly moving, vibrating and noisy. The power line is vulnerable to damage due to external forces such as drag, friction or mechanical extrusion, which will damage the insulation strength and cause personal injury and death due to electric shock. In order to prevent accidents, hand-held electric tools should be selected correctly.