The insulating cardboard between the foot of the clamp under the iron core and the rail is off or damaged, causing the laminations at the foot of the foot to collide and cause grounding;
Due to the abrasion of the submersible pump shaft, metal powder enters the fuel tank, and the bottom of the fuel tank is not deposited. A bridge is formed under the action of electromagnetic force. The lower iron reel is connected with the foot or the bottom of the tank to form a multi-point grounding;
The thermometer seat cover on the fuel tank cover is too long, and it collides with the upper clamp or the edge of the iron choke and the side pillar to form a new grounding point;
The wooden pad between the lower clamp and the iron choke ladder is damp or has a dirty surface, and there is more sludge. When the insulation resistance value is reduced to zero, it forms a multi-point grounding;
Metal foreign objects such as iron nails, welding rod heads, etc. fall into the fuel tank to make the iron core lamination communicate with the tank body to form a ground:
After the transformer is installed, the positioning pin used for transportation on the top cover of the fuel tank is not turned over or removed, forming a multi-point grounding.