Explosion Proof Motor Bascis: Working Principe, Overhaul and Maintenance

Explosion-proof motor is a kind of motor that can be used in flammable and explosive factories, and does not generate electric sparks during operation. In a very short period of time, a large amount of energy is released, high temperature is generated, and a large amount of gas is released, causing a high-pressure chemical reaction in the surrounding medium.

How does explosion proof motor work？

The electrical equipment cover is installed in an enclosure, which has a structure that can withstand the explosion pressure of the internal explosive mixture and can prevent the internal explosion from propagating to the explosive mixture around the enclosure (flameproof type); it is impossible to make the live parts of the motor impossible generate sparks, arcs or dangerous temperatures sufficient to cause an explosion hazard, or isolate live parts that may produce these phenomena from the explosive mixture so that they cannot come into contact with each other or reach an explosive hazard level (increased safety, ventilated).

How to overhaul explosion proof motor?

1. When the explosion proof motor is disassembled, all bolts, brush holders, pads, etc. must be marked, and the explosion-proof motor must protect the explosion-proof surface.
2. When disassembling (pulling) the motor rotor, the wire rope used should not touch the rotor, bearing, fan, oil ring and coil; the rotor should be placed on the hard pad.
3. When overhauling the stator of explosion proof electric motor, use compressed air to blow out the ventilation ditch and the coil ends. To avoid damage to the insulation, a tick made of wood or insulating board must be used when removing dirt from the stator coils.
4. When checking the stator core, pay attention to whether the stator core is compressed. If the core is found to be loose, a wedge made of an insulating plate should be inserted into the slack; when checking the slot of the stator coil, special attention should be paid to the coil Notch section. Loose and discolored wedges must be dealt with.
5. When checking the end of the coil of explosion proof electric motor, check whether the insulation is damaged or not and the condition of the paint film. Pay attention to the fixing status of the end, and if there is any looseness at the end, a spacer should be added, or a new spacer and wire tie should be used to fasten the end; if the insulating paint film at the end of the coil cracks or falls off, it should be re-strengthened insulation.
6. After the motor is decomposed, remove the bearing and wash it with kerosene or gasoline. When the clearance of the bearing exceeds the allowable value, the rolling bearing should be replaced.
7. When overhauling the cooling system of explosion proof induction motor , the temperature measurement, fan blades and other ancillary devices must be checked at the same time.

How to maintain explosion proof motor?

1. For the starting equipment of the explosion proof motor, remove the external dust and dirt in time, wipe the contacts, check whether there are burn marks on each wiring part, and whether the grounding wire is in good condition.
2. Check and clean the explosion proof electric motor's terminals. Check if the junction box terminal screws are loose.
3. Check the screws of each fixing part of explosion proof electric motor and tighten the loose nuts.
4. Clean and wipe the motor. Clean the dust and oil on the outside of the motor base in time. If the use environment is dusty, clean it once a day.
5. The insulating ability of insulating materials varies with the degree of drying, so it is very important to check the drying of the motor windings. Moisture in the working environment of the explosion proof motor, corrosive gases in the work room and other factors will damage the insulation of the motor.
6. Check the transmission device, check whether the pulley or coupling is broken or damaged, whether the installation is firm; whether the belt and its coupling buckle are in good condition.
7. Maintenance of the carbon brush of the explosion proof electric motor. During the operation of the flameproof motor, the wear of the carbon brush is a very important factor that causes the motor to be scrapped. Therefore, when using the motor, pay attention to the maintenance of the carbon brush of the motor, that is to say, when using the motor During the process, the carbon brushes should be replaced regularly, so that the use process can be smoother.
8. Inspection and maintenance of bearings. Bearings should be cleaned and replaced with grease or lubricating oil after a period of use. The time of cleaning and oil change should be determined according to the working conditions of the flameproof motor, the working environment, the degree of cleanliness, and the type of lubricant. Generally, it should be cleaned once every 3-6 months of operation, and the grease should be replaced again. When the oil temperature is high, or the motor with poor environmental conditions and a lot of dust should be cleaned and changed frequently.
9. During the operation of the explosion proof motor, there is often a problem that the motor will make a strange sound, mainly the cooling fan. During the use process, the dust on the cooling fan is not cleaned in time, which causes the motor to appear in the process of running. In order to avoid the phenomenon of abnormal operation, ensure that the cooling fan of the motor is clean during the use of the motor.
10. In order to avoid rust on the explosion-proof surface, oil or 204-1 replacement type anti-rust oil should be applied to the explosion-proof surface.

In short, no matter what type of explosion-proof motor, its casing has high sealing to reduce or prevent dust from entering the casing, even if it enters, it will not form an ignition hazard, and the surface temperature of the casing does not exceed the specified temperature, The working principle of the explosion-proof motor is to play an explosion-proof role as a running motor in a place where there is a danger of explosion.