Publish Time: 2023-09-28 Origin: Site
This article briefly introduces the electric motor fault diagnosis and troubleshooting methods, and teaches you how to properly handle the electric motor-related problems.
Here is the list
Stator winding insulation breakdown, short circuit
Stator core relaxation
Short circuit between iron filings
electric motor overheating
(1) The stator winding is damp. For electric motors that have been out of service for a long time or have been overhauled for a long time, the insulation resistance should be measured before being put into operation, and those with faults should not be put into operation. A wet electric motor should dry out.
(2) The winding itself is defective or the maintenance process is improper, resulting in insulation breakdown or mechanical damage of the winding. The insulating material should be selected according to the specified insulation grade, and the winding installation and impregnation drying should be carried out in strict accordance with the process requirements.
(3) The winding is overheated. When the insulation is overheated, the insulation performance will be reduced, and sometimes the insulation breakdown will be caused rapidly at high temperature. Routine inspections should be strengthened to prevent overheating of various parts of the electric motor and damage to the winding insulation.
(4) Insulation aging. Generally, the electric motor runs for more than 15 to 20 years, and its winding insulation is aging, the electrical performance changes, and even the insulation is broken down. The maintenance and preventive test of the electric motor should be done well. If the insulation is found to be unqualified, the defective winding insulation should be replaced or the winding should be replaced in time to prolong the service life of the electric motor.
(5) Metal foreign objects enter the inside of the electric motor. After the electric motor is overhauled, do not leave metal objects, parts or tools in the stator cavity; tie the rotor's binding wires and fasten the ends to prevent loosening due to centrifugal force. take off.
(6) Overvoltage breakdown:
①The line is struck by lightning, and the lightning protection is not perfect. Lightning protection facilities should be perfect.
② Misoperation, such as the electric motor no-load voltage rises too high. The electric motor should be boosted in strict accordance with the operating procedures to prevent misoperation.
③For the internal overvoltage of the electric motor, including running overvoltage, arc grounding overvoltage and resonance overvoltage, etc., the preventive test of the winding insulation should be strengthened, and the insulation defects of the stator winding should be found and eliminated in time.
The iron core was not tightened properly due to improper manufacturing and assembly. If the whole iron core is loose, for small electric motors, two iron plates smaller than the inner diameter of the stator winding end can be used, and the iron core can be tightened with stud bolts. After restoring the original shape, tighten the original clamping bolt of the iron core. If the iron core is partially loose, you can first apply silicon steel sheet paint between the loose pieces, and then drive hard insulating material into the loose parts.
(1) The lamination of the iron core is loose, the iron core vibrates when the electric motor is running, and the insulation is damaged; the insulation of individual parts of the iron core is damaged or the iron core is partially overheated, resulting in insulation aging.
(2) There are burrs or mechanical damage on the edge of the iron core during maintenance. Deburr with a fine file, trim damage, clean the surface, and apply a coat of silicon steel flake paint.
(3) If there is a short circuit of solder or copper particles in the iron core, the metal weld should be scraped or chiseled, and the surface treatment should be done.
(4) An arc short circuit occurs in the winding, which may also cause a short circuit in the iron core. The burnt part should be removed with a chisel and the surface should be well prepared.
(1) The electric motor does not operate according to the specified technical conditions. For example, if the stator voltage is too high, the iron loss will increase; if the load current is too large, the copper loss of the stator winding will increase; if the frequency is too low, the speed of the cooling fan will decrease, affecting the heat dissipation of the electric motor; if the power factor is too low, the excitation current of the rotor will increase. increase, causing the rotor to heat up. It should be checked whether the indication of the monitoring instrument is normal. If it is not normal, necessary adjustments and treatments should be carried out to make the electric motor run according to the specified technical conditions.
Hangzhou New Hengli Electric Machine MFG. Co., Ltd. works has been named the provincial advanced enterprise by Zhejiang provincial government and become a state grade-2 enterprise in 1988. Our motor max-power reaches 15000kW (A.C. motor), 2800kW (D.C. motor), and max-center-high dimension of our motor reaches 1250mm.