Motor is not allowed to run without ground wire

The material of motor casing is cast iron, cast aluminium alloy. Small power motor domestic commonly used cast iron, aluminum alloy, steel (steel) shell, workpiece processing, large quantity, long production cycle; the operator working environment of poor sanitation, labor intensity; the waste of energy and material waste fire.

The world, developed countries such as Germany, Japan and other countries as early as the pods in the middle of this century it has been widely used in the steel shell Jing jian. This new type of casing processing technology is a very few finishing process. Some domestic motor manufacturers in the early 70s began to study the manufacture of steel chassis, and in the middle of 80s to form a certain volume. But because of the material under pressure for shear type "U" (or "W" type) by pressing "O" type (manual or electric welding, carbon dioxide welding) - one car 118 pieces of plastic processing and polishing process (without foot shell), with many types of equipment, the proportion of artificial influence the factors of quality, quality assurance difficult.

Currently, some advanced countries have adopted advanced special processing equipment to manufacture steel plate, which has high mechanization and automation. In the advanced countries the motor market appears on the small power motor has been generally for the steel casing motor. In 1989, China has begun to produce a steel casing of the temple with the processing equipment - steel casing roll machine, motor shell welding machine, etc.. In recent years, the price of materials is very high, and the domestic market is weak. In order to reduce the cost of the motor, to improve the quality of steel casing and small power motors in China into the motor market in developed countries, and occupied the market, must carry out the study on new technology for manufacturing motor shell plate.

When the motor stator winding insulation failure, aging or stator windings and motor shell collision when the insulating shell electric motor shell has very high voltage to ground. If the motor does not have a ground wire, when a person touches the motor casing, a strong electric current passes through the human body

Into the earth, it will cause casualties.

If the motor casing is connected to the ground, because of the resistance of the ground is very small, the electric potential of the motor shell and the earth is equal, people will not contact the motor shell shock. In fact, serious leakage of motor, such as stator winding and shell collision, caused by earthing, caused by short-circuit current is very high, the relay protection device of motor terminal box, or fuse, the power supply is cut off, the motor stops. Other electrical equipment shell also need grounding wire, the truth is the same. Therefore, in order to ensure personal safety, the motor is not allowed to run the ground wire.