The explosion-proof motor must be reliably grounded. The closed production workshop of a small flour mill in Xujiang, a Jiangsu agile motor factory, is actually a reinforced concrete brick-concrete structure, taking into account the characteristics of the flour processing industry and After all the metal structures such as steel windows are connected to the grid, they are well grounded. For more than a decade, the operation of the equipment has been carried out for 1 day. The technical transformation has been carried out for 1 day, and the new platform has been installed in the 4518225 River 2 explosion-proof phase. Asynchronous motors, in use, continue to reflect the problem, the motor in the heart of the flour conveyor fan, the load in operation can not maintain uniform and stable, so the body vibration is larger, in order to adapt to this condition, the motor bottom loading There is only a bowl-shaped rubber cushion cushion, and the ducts made of canvas are used as a telescopic transition device on the pipelines entering and exiting the fan. The concentration of flour dust in the environment is not too large a few days later. Workers on duty are on the motor. When the dust on the seat was wiped, it was found that it was widely exposed to the bottom of the hot fried finger.
The brush is prone to bristling, dust is not clean; if you increase the pressure, you feel a bit numb hands and feet, when you directly touch the motor shell, found that the motor leakage. With the electric pen test, the oxygen bubble is very bright; with 0 890 8908 digits, dialed to 700 files, the amount of steel window frame voltage near the ground to the ground is high, only jumping on the number of 1 is no longer significant. Afterwards, they transported the motor to our factory. After checking and checking the test bench, it was confirmed that the motor's insulation withstand voltage, no-load short-circuit vibration noise and other indicators reached the factory level, and there was no leakage at all. After the motor returns to the user, it soon reports that the motor casing is still energized, and it is required to go to the shop floor where the service is running in the motor room. Contact the machine base with the electric pen, the bulb is bright, and touch the nearby steel window frame with the other hand. He felt hemp hand, indicating that the voltage was indeed higher. The pointer and 5 file experts commented on the survey, intended to hit 400 in an instant, slow down by 100.
Change the 刖 25 file test, the pointer instantly hit 2 and dropped to 50, switch to 50 files, after the pointer hit 40 and then dropped to 10, there is an induced voltage on the machine seat; then change to 500, file measurement, red pen Pick up the seat, the pointer at 36, left and right swing, red and black two pens transposition, then the pointer counterattack, Yiming Ming seat also carries a positive charge. The higher DC voltage should be the positive charge generated by contact friction when the flour dust particles are transported in long distances in the metal pipe. It is transported to the base by the fan impeller and the impact is separated, and the rubber pad and the canvas sleeve are insulated. , The positive charge on the base can't leak and gradually accumulate to form a comprehensive analysis of the above phenomenon that the motor may be located in a floating position and check that the motor is connected with copper core ground wire with enough cross section to meet the core cable wiring. With the cabinet directly to the cabinet ground. The discovery is empty. It's amazing. This is the root cause of all kinds of electrified phenomena. Later, it was found that during the process of technological transformation, the length of the original grounding cable was not enough due to the change in the position of the motor terminal box. If you add a paragraph to the motor, you hate it. Therefore, you loosen the grounding point in the cabinet and pull the ground wire to the motor. But you forgot to fix the section, causing you to be troubled.
From this point of view, the installation and wiring of gas-fired equipment should be reviewed and approved by special personnel. It is necessary not only to find out the electrical circuit but also to find out each grounding point. All the flammable dust in the flour processing plant is flying. It is an explosive environment. Except strictly forbidden fireworks, the metal shells of all electrical equipment used at the site must be properly grounded, so that inductive and electrostatic charges can be drained in time to eliminate hidden dangers and ensure safe operation. After the motor was connected to the ground, it was called for several months. It was working normally and it was safe.
Flammable dust environment selection Flameproof electrical equipment should be careful explosion-proof Electrical equipment is a reliable grounding is related to the explosion of dangerous personal and explosion-proof safety measures of the explosion-proof motor must be reliable grounding example introduced in the article, once again remind the use of the department, The explosion-proof motor is called and must be called properly grounded. And should be regularly checked and maintained.
The explosion-proof motor must be reliably grounded. The paper mentions that the flour mill has selected Taiwan 1;2212 explosion-proof motor 1 for flammable dust such as powder powder.
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