Case of electric shock accident caused by welding

During the welding process, the two output ends of the welding machine are in contact with the welding workpiece and the welding rod on the welding clamp through wires. Since both are conductors, the voltage difference between the welding rod and the workpiece generates an arc for welding. Generally, the input end of the welding machine has an AC voltage of 220VAC or 380VAC, and the no-load output end also has a DC voltage of 55~90V or an AC voltage of 60~80V. If the worker's body directly or indirectly touches the input or output end of the welding machine, there is a certain degree of accidental electric shock risk. Especially on rainy days, when there is water accumulation in the welding workplace, or when the worker's hands and body are wet, the accidental risk will be greatly increased.

Dangerous factors:

1. Replace the welding rod by hand without stopping the welding machine.

2. Accidentally touch the exposed conductive part or welding rod of the welding clamp.

3. During welding, lean or squat on the welding workpiece, such as large machinery, steel, structure, oil cylinder, etc.

4. Lie on your back on the ground and weld at the bottom of the workpiece.

5. Welding in stagnant water. Preventive measures:

1. Good working habits are the fundamental guarantee of safety:

(1) Regularly check and repair welding tools, the metal shell of the welding machine should be reliably grounded, and use safe, qualified and good welding tools;

(2) Wear qualified labor protection equipment and avoid direct contact with the live parts of the welding workpiece, which can effectively prevent welding electric shock accidents;

(3) Increasing the resistance value of the overall leakage circuit can reduce the leakage current passing through the victim's body when electric shock occurs, thereby reducing the harm;

(4) The switch of the welding machine should have obvious "on" and "off" signs;

(5) The welding machine should not be far away from the welding site so that the power supply of the welding machine can be quickly cut off when necessary or when an accident occurs;

(6) When interrupting welding, the power supply of the welding machine should be turned off and the residual welding rod on the welding clamp should be removed.

2. Choose a safe working environment for work:

(1) Do not weld in the open air when it is raining, and do not stand in water or in places with serious water accumulation to weld. If welding must be done in a damp or water-free place, stand on an insulating rubber sheet, dry wood board, or non-conductive workbench;

(2) When welding in a closed place, such as inside a cylinder or large machinery, be especially careful to prevent electric shock;

(3) When welding at height, at least have a safe and stable working platform. Otherwise, even a slight electric shock may cause the welder to lose balance and fall, causing personal injury.