The handheld electric tools used by electricians are used in harsh environments, with continuous movement, high vibration, and high noise during use. The power cord is easily damaged by external forces such as drag, friction, or mechanical compression, which can damage the insulation strength and cause personal injury or death due to electric shock. To prevent accidents, handheld electric tools should be selected correctly.

Selection method

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

2. In general situations, Class II products should be selected. This type of equipment has dual insulation and is relatively safe to use.

3. When working in damp places or metal structures with good conductivity, Class II or III products should be selected.

4. When working in narrow areas such as metal containers, pipelines, boilers, etc., Class III products should be selected.

If it is necessary to use Class I products, necessary other safety measures should be taken according to safety requirements, such as installing leakage protectors, safety isolation transformers, etc.

Usage method

1. Before use, it should be carefully inspected to ensure that its appearance is undamaged, the switch action is flexible and free from jamming, and the power lead and the outer shell of the power tool should be intact. Use a 500V megohmmeter to measure the insulation resistance between the winding and the casing, which should not be less than 0.5 megohms. The insulation resistance values are shown in the attached table.

2. Handheld electric tools with metal shells should have reliable protective grounding wires. The power lead is a multi-core soft rubber sheathed cable, and its grounding protection wire should be firmly connected at both ends.

3. Handheld electric tools should be used by dedicated personnel with certain professional knowledge. Strictly follow the relevant safety operating procedures during use.

4. Before use, it is necessary to check whether the relevant electrical 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.

When using Class I handheld electric tools, the user must wear protective equipment that meets the regulations and be equipped with qualified protective equipment. And corresponding safety measures to prevent electric shock should be taken according to regulations, such as installing leakage protectors in the power circuit, or wearing insulated gloves, shoes, or standing on insulation pads.

When using Class II handheld electric tools in damp and narrow areas, a leakage switch should be installed, with a working current of less than 1.5mA and an action time of less than or equal to 0.1 seconds. And the leakage switch should be placed in the container and supervised by a dedicated person.

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

Handheld electric tools, especially those equipped with imbalanced mass rotating components, such as tools with crank connecting rod piston impact devices and tools with eccentric devices (such as electric hammers, electric pickaxes, etc.), will generate significant vibration during movement. When operating these tools, vibrations are transmitted to the operator's hands, wrists, and shoulders. With the widespread application of electric tools, the vibration hazards they generate are receiving increasing attention.

Common measures for occupational disease prevention include carefully maintaining and maintaining tools in accordance with the manufacturer's instructions; When different tools can be rotated, use operating methods that generate lower vibrations as much as possible; Tools should be prevented from generating cold gases and liquids around the operator's hands; If possible, in cold conditions, the operating handle of the tool should be heated; Avoid using tools with high pressure on the skin caused by the shape of the handle in the contact area of the sub object; When optional, tools requiring small contact pressure (holding force and feeding force) shall be selected; Using shock absorbing gloves; Wear gloves during operation to avoid hearing damage. [3] Selecting and Using Editing

The handheld electric tools used by electricians are used in harsh environments, with continuous movement, high vibration, and high noise during use. The power cord is easily damaged by external forces such as drag, friction, or mechanical compression, which can damage the insulation strength and cause personal injury or death due to electric shock. To prevent accidents, handheld electric tools should be selected correctly.