Common faults and causes of explosion-proof motor and matters needing attention in maintenance

Xi 'an explosion-proof motor is a kind of motor that can be used in flammable and explosive places, and it does not produce electric sparks when running. Today, I will introduce you to the common faults of explosion-proof motors, their causes and maintenance precautions. Interested friends can take a look!

1. Fault symptom: The motor can't start, and there is no sound.

Cause: ① The fuse is blown. ② Starter tripping. (3) the power supply has no electricity.

2. Failure phenomenon: the motor can't start, and there is a buzzing sound.

Reason: ① One phase of the power cord is broken, or one phase of the fuse is blown, or one phase of the motor winding is broken. ② The air gap between the stator and the rotor is abnormal, which causes the stator and the rotor to collide. ③ Bearing damage. (4) is driven by mechanical stuck.

3. Fault phenomenon: the fuse is blown when the motor starts.

Reason: ① The stator coils are connected in opposite directions. ② The stator coil is short-circuited or grounded. ③ Bearing damage. ④ The drive belt is too tight. ⑤ Being stuck by driven machinery. ⑥ Misoperation during starting.

4. Fault phenomenon: The motor speed is low after starting.

Reason: ① The power supply voltage is too low. ② Connect the motor with triangle connection into a star shape. ③ The stator coil is short-circuited. ④ The short-circuit ring and cage bars of the rotor are broken or welded. ⑤ Motor overload.

5. Fault phenomenon: The motor temperature is too high, but the current does not exceed the rated value.

Cause: ① The ambient temperature is too high. ② The ventilation duct of the motor is blocked. ③ Too much sludge and dust in the motor will affect the heat dissipation.

6. Failure phenomenon: the motor has an explosion during operation.

Cause: ① The coil is temporarily grounded. ② The coil is temporarily short-circuited.

Maintenance precautions

1. The explosion-proof motor shall not be disassembled at will; During disassembly and maintenance, the explosion-proof surface of the parts cannot be used as the fulcrum of the crowbar, and it is not allowed to knock or hit the explosion-proof surface.

2. When disassembling the motor, remove the fan and fan first, then remove the bolts of the end cover and bearing cover with a casing wrench. Then, use logs or copper bars to impact the shaft along the axial direction to separate the end cover from the base, and then remove the rotor. Dismantle the parts, put the explosion-proof surface upward, cover it with rubber or cloth liner, and be careful not to lose the fastening bolts and spring pads.

3. During paint dipping and assembly, the insulating paint or dirt attached to the explosion-proof surface should be cleaned, and hard objects such as iron sheets should not be scratched, but the uneven places can be ground with oilstone.

4. If the explosion-proof surface is damaged, it is necessary to use lead-tin solder HISnPb58-2, the flux is 30% hydrochloric acid (for steel parts) or tin-zinc solder containing 58~60% tin, the flux is 30% ammonium chloride and 70% zinc chloride, and the mixed solution of 100~150% water (for cast iron parts) for welding repair. The combination of solder and parts should be firm.

5. In order to prevent the explosion-proof surface from rusting, apply engine oil or 204-1 replacement antirust oil on the explosion-proof surface.