Cooling and Water Treatment Methods for Explosion-proof Motors

Ⅰ. How to cool down the explosion-proof motor?

1. The working environment of the motor should be ventilated frequently to avoid high temperature caused by the closed environment. The temperature rise limit is further reduced by 10°C on the basis of the insulation level regulations.

2. Reduce the time of motor overload operation. In abnormal operating conditions, cut off the power supply with the help of protection devices. Another assessment index for the increased safety motor to prevent overheating is the starting current ratio.

3. The working current should be controlled within the rated current range as much as possible. During normal operation, if the flameproof electrical equipment motor suddenly stalls, the stall time tE should be allowed to be greater than 5s. During this time, the explosion-proof motor will not generate dangerous overheating; at the same time, the overheating protection relay will act to cut off the power supply.

4. Check the explosion-proof motor fan filter. Excessive dust will block the mesh, resulting in poor ventilation of the motor and abnormal heating.

5. In the extreme environment of high temperature, the motor should be regularly maintained. A relatively simple method is to improve the internal cleanliness of the motor: after cutting off the power supply, open the covers on both sides for dust removal such as vacuum cleaners.

Ⅱ. The treatment method of explosion-proof motor water

1. Disconnect the power supply and remove the explosion-proof motor power supply wiring;

2. Remove the front and rear covers of the explosion-proof motor;

3. Wash the explosion-proof motor bearing lubricating oil with gasoline or kerosene, and add lubricating oil after drying;

4. Dry the stator of the explosion-proof motor with an oven or a light bulb;

5. Wipe the rotor of explosion-proof motor with a clean rag;

6. Check the explosion-proof motor junction box;

7. The explosion-proof motor is installed and restored as a whole, and it can be rotated flexibly by hand without jamming;

8. Use a shaker (500 or 1000V) to measure the ground insulation of the flame proof conversions motor, and the insulation resistance must be greater than 0.5 megohm;

9. Connect the power to the test run for a period of time (30 minutes), if there is no problem, it can be used.

Ⅲ. Maintenance of water-inlet explosion-proof motor

1. Remove the sludge and impurities outside the explosion-proof motor, but do not rotate the motor shaft.

2. Disassemble the body of the explosion-proof vfd frequency converter, clean the sludge and water stains on the inner cavity of the casing, the rotor and the slip ring, check whether the winding is de-soldered, whether the brush is corroded and stuck in the brush holder, and whether the brush pressure is normal. Check whether the brush and the surface of the slip ring are in close contact. If any fault is found, it should be eliminated.

3. Dry the windings of the explosion-proof motor. It can be baked with an incandescent lamp to evaporate the water, or it can be placed in a ventilated place to dry naturally. However, do not use current heating or open flame baking to prevent the winding of the explosion-proof motor from short-circuiting or baking the insulation layer. After drying, use a megohmmeter or a multimeter to check the insulation performance of each winding. If it is found that there is poor insulation, it should be repaired.

4. Reinstall the body of the explosion-proof motor and carry out the trial operation of the explosion-proof motor. If there is no problem in the test run, it can be put into use.