Electric shock while welding

The terminal board was burned and the welding machine casing was electrified, causing an electric shock accident

The main process of the accident:

Two welders in a factory, A and B, were spot welding an iron shell and found that a section of the welding machine lead coil was broken, so A found a section of soft wire and asked B to replace it. When B was replacing the wire, he found that the bolts of the primary wire connection board were loose, so he tightened it with a wrench. A was not present at the time, and then B tried welding a few times and left the work site. After A returned, he started spot welding without understanding the situation. He only welded once and then screamed and fell to the ground. Worker C immediately turned off the power, but he died in the end because of untimely rescue.

The main cause of the accident:

(1) The terminal board was burned, and the coil and the welding machine casing touched each other, causing a short circuit

(2) The welding machine casing was not grounded

How to prevent accidents?

(1) Equipment maintenance should be carried out by electricians

(2) Welding equipment should be grounded