Measures against electric shock in the hottest man

Anti electric shock measures for manual arc welding

manual arc welding is the most widely used welding process at present, and electric shock accidents caused by manual arc welding also occur from time to time

the welding power supply is connected to the 220/380V power network. Once the human body contacts this part of the line (such as the socket of the welding machine, switch or damaged power line, etc.), it is difficult to get rid of it. The no-load voltage of the welding machine generally exceeds the safe voltage, but because the voltage is not very high, it is easy to be ignored. No load voltage of manual arc welding machine is about 70 volts; When replacing the welding rod, if the welder's hand touches the welding tongs, a circuit will be formed through one hand and two feet, resulting in an electric shock accident. Welding electric shock casualties mostly occur in the following situations, such as sweating or operating on wet ground in summer, wet shoes and socks, thin soles, etc. At this time, the resistance of the human body is about 1600 ohms, and the current passing through the human body is about 44 ma. At this time, the welder's hand will cramp, and even can't get rid of it, and there will be life 5 Graph curve scale automatic Zui optimization auto scale danger. It should be emphasized that electric welding operators who climb high will also fall from high places due to convulsion, numbness and panic caused by electric shock, causing secondary accidents

in addition, the welding machine and cable are often overloaded; Corroded by dust, etc., and exposed to wind, sun, rain, etc. when working outdoors; The insulation layer is easy to age and deteriorate, which is prone to electric leakage, resulting in electric shock accidents

electric shock accidents during welding occur in the following two cases: one is to produce cracks, which is to touch the electrified body during the normal operation of the welding equipment; Such as the electric shock near the terminal, welding gun and welding tongs, or the high-voltage electricity, that is, the so-called direct electric shock; The other is that it is not electrified under normal conditions; Electric shock caused by accidental electrification of conductors (such as leakage welding machine shell, cable with damaged insulation sheath, etc.) due to insulation damage or electrical circuit failure, that is, the so-called indirect electric shock

in view of the causes of electric shock accidents in manual arc welding, it is recommended to take the following safety precautions:

1. Before welding, check whether the welding equipment and tools are safe and reliable. For example, whether the shell of the welding machine is grounded and whether the connection points of the welding machine are in good contact; Digital impact testing machine adopts high-precision encoder technology to check whether the insulation of welding cable is damaged. It is not allowed to start operation without safety inspection

the swing angle needs to be adjusted by professionals

2. The welder's hands and body should not touch the conductor of the secondary circuit casually, and should not rely on the workbench, weldment or contact the welding tongs and other electrified bodies. For welding operations with high no-load voltage of the welding machine and when operating in wet working places, rubber insulation pads should also be laid on the ground near the operation console

3. The following operations should be carried out after cutting off the power switch: transfer the working place and move the welding machine; Replace the fuse; Maintenance of welding machine in case of failure; Change the welding machine joint; It is necessary to modify the layout of the secondary circuit due to the replacement of weldments. Wear insulating gloves when pushing and pulling the knife switch; At the same time, the welder's head should be tilted to prevent the arc spark from burning the face

4. When welding in metal containers, metal structures and other narrow workplaces, the risk of electric shock is the greatest, and special protective measures must be taken. Such as rubber pads, leather gloves, insulating shoes, etc

5. Under no circumstances should the welding operator make himself or the transmission part of the machinery and equipment into a welding circuit, and it is strictly prohibited to use the metal structure of the plant, rail (pipe) and other connecting lines as conductors

6. The grounding protection device of the welding machine must be complete and effective. At the same time, the welding machine must be equipped with the automatic power-off protection device of the electric welding machine without load

7. There should be no joint in the middle of the welding cable. If a short wire is needed to be extended, there should be no more than 2 joints. Joints: they should be made of copper material and ensure good insulation

8. Strengthen personal protection. Welders' personal protective equipment includes intact work clothes, insulating gloves, overshoes, etc

9. The installation, inspection and repair of electric welding equipment must be carried out by electricians, and the power supply of temporary construction points should be connected by electricians