High pressure fan motor damage is a common fault in the whole process of application of high pressure fan. The key causes of motor damage are: motor open phase, motor overload operation, equipment failure, etc.
According to the statistical analysis, the common faults of three-phase asynchronous motors used in production and manufacturing are about 85% of the common faults of electrical equipment with winding resistance burnt out, and about 15% of the common faults of the organization and others. In fact, the reasons for winding resistance burnt out are mostly open phase operation or load operation, winding resistance grounding device and winding resistance two-color or turn to turn short circuit faults（ In case of star operation, two-phase winding will be damaged; in case of triangle operation, one phase winding will be damaged.)
The second is the friction of the rotor (motor cleaning), less loose oil of broken strip rolling bearing and other mechanical equipment (the motor is mainly characterized by a group of short circuit, no black, motor damage). However, the damage of high-voltage fan motor caused by electrical equipment is more common and very complicated. Some customers usually avoid responsibility. Under the excuse of Hank's current quality assurance policy, some unreasonable requirements will be clearly put forward in order to assist many business personnel and identify the real reasons of the damage, I mainly analyze the cause of motor winding ablation from the perspective of electrical equipment, and propose a relative solution.
一、Open phase operation
1.Common fault conditions
The motor can not be started, even if it can be started with full load, the speed ratio will gradually increase and there will be a buzz; The motor is hot with burning smell.
2.Inspection results
Remove the motor bearing end cover, and it can be seen that there is a 1 / 3 or 2 / 3 polar winding or coke or dark coffee color on the top of the winding resistance.
3.Common fault causes and Solutions
(1)Motor power supply system control circuit fuse control circuit bad contact phenomenon or mechanical equipment damage, resulting in a phase fuse break.
(2)The specifications and models of three-phase fuses in the control circuit of motor power supply system are different, and the fuses with small volume are burnt out. According to the motor output power size, the fuse with the same specification and model shall be replaced.
(3)The power switch (knife switch, rubber cover power switch, etc.) in the control circuit of the motor power supply system and the circuit breaker of AC contactor are in poor contact (scald or loose). Repair and adjust the dynamic and static circuit breakers to make them touch well.
(4)A phase of a line is broken. Find out the disconnection and connect firmly.
(5)There is no welding between the winding resistance wires of the motor, resulting in poor contact. Carefully check the winding resistance electrode connecting wire of the motor and weld it firmly.
二、Load operation
1.Common fault conditions
The high-pressure fan operates in the high working pressure area for a long time, which causes the motor excitation current to expand and the motor current to exceed the rated current; The temperature rise of the motor exceeds the rated value. Or dirty things are sucked into the high-pressure fan, the motor is in overload operation, or the motor bearing is not lubricated or the sand frame is damaged; Stator and motor rotor core friction, also known as sweeping
2.The results show that all three groups of winding resistances of the motor are damaged;
3.Common fault causes and Solutions
(1)When the high pressure fan operates in the high working pressure area for a long time, the motor with suitable output power should be removed or replaced as much as possible.
(2)Dirty things are sucked into the high-voltage fan, causing the motor load and burning the motor winding. Check the front-end development department of the high-pressure fan to take effective measures to solve the dirty things, so that it can rotate easily.
(3)If the power supply voltage is too high or too low, it is necessary to refit the three-phase power regulator compensation cabinet. The motor has serious moisture regain or corrosion for a long time, the steam body is corroded, and the grounding resistance is reduced.
(4)The lack of rolling bearing oil, polishing or the different mechanical equipment of motor rotor cause the motor rotor to sweep the bore and make the motor current exceed the rated current. First of all, check the damage condition of the rolling bearing carefully. If it doesn't pass the standard, replace it with a new one; Secondly, clean rolling bearing and introduce proper grease. Then check the motor bearing end cover. If the management center hole of bearing end cover is damaged and the motor rotor is not in the same center, solve the problem of bearing end cover and carry out solution or replacement.
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