Reasons and Solutions for Burning-out of side channel blower

 Blower Technology     |      2019-09-17 16:29
The burnout of side channel blower motor is a common fault in the process of using side channel blower. The main causes of motor burnout are: motor phase absence, motor overload operation, mechanical failure and so on.
According to statistics, the faults of three-phase asynchronous motors used in production are about 85% of the electric faults caused by burned windings, 15% of the mechanical faults and other faults. Specifically, the causes of burned windings are mostly short-phase operation or overload operation, winding grounding and winding phase or turn-to-turn short circuit. (Two-phase winding will be burned when star-shaped winding runs, one-phase winding will be burned when triangle-shaped winding runs)
Secondly, the mechanical reasons such as friction between stator and rotor (motor sweeping chamber), oil shortage of broken bar bearings and loose frame (the motor is characterized by a group of wire wraps breaking, no blackening, motor burning). But the burning of high-voltage fan motor caused by electrical reasons is the most common and quite complex. Some customers often put forward some unreasonable demands in order to shirk their responsibilities. In order to help the sales staff and identify the real cause of the burning of high-voltage fan motor, I focus on the analysis of electricity from the electrical point of view. The causes of winding burnout and the corresponding treatment methods are put forward.
I. Phase-missing operation
1. Fault phenomena
Motor can not start, even if no load can start, the speed slowly rises, there is buzz; motor smoke and heat, and accompanied by burning smell.
2. Inspection results
When the motor end cap is removed, 1/3 or 2/3 of the polar windings or cokes at the end of the winding can be seen or turned dark brown.
3. Causes of failure and treatment methods
(1) The fuse circuit of the power supply circuit of the motor is badly contacted or mechanically damaged, resulting in the fuse of a certain phase.
(2) The three-phase fuses in the power supply circuit of the motor have different specifications, and the fuses with small capacity are burnt out. The fuse of the same specification should be replaced according to the power of the motor.
(3) Bad contact (burns or loosening) between switches (disconnectors, rubber cover switches, etc.) and contactors in the power supply circuit of motors. Repair and adjust the dynamic and static contacts to make them in good contact.
(4) Some phase of the line is out of phase. Find out the broken line and connect firmly.
(5) Virtual welding between motor windings leads to poor contact. Check the connection wire of motor winding carefully and solder firmly.
II. Overload Operation
1. Fault phenomena
The side channel blower operates in high-pressure area for a long time, which leads to the increase of motor shaft power, motor current exceeding rated value, and motor temperature rise exceeding rated temperature rise. Or the foreign body sucked into the side channel blower, is that the motor is in overload operation, or the motor bearings are not damaged by grease or sand frame; stator and rotor core friction, commonly known as sweeping chamber.
2. Inspection results show that all three windings of the motor are burnt down.
3. Causes of failure and treatment methods
(1) When the side channel blower operates in the high-pressure area for a long time, it should properly relieve the pressure or replace the motor with suitable power.
(2) Foreign body is sucked into side channel blower, which causes motor overload and burns motor winding. Check the front end of the side channel blower and take measures to deal with foreign bodies so as to make it rotate flexibly.
(3) If the power supply voltage is too high or too low, a three-phase power supply voltage stabilization compensation cabinet should be installed. For a long time, the motor is seriously damped or corroded by corrosive gases, and the insulation resistance decreases.
(4) Shortage of oil in bearings, dry grinding or mechanical discentration of the rotor lead to the sweeping of the motor rotor, which causes the motor current to exceed the rated value. First of all, the wear condition of bearings should be carefully checked. If they are not qualified, new bearings should be replaced. Secondly, the bearings should be cleaned and a proper amount of grease should be injected. Then check the motor end cap. If the center hole of the end cap is abrasive and the rotor is not concentric, the end cap should be treated or replaced.