Overheating is the biggest culprit of electric motor failure.
In fact, the other four causes listed in this article made the list in part because of the heat they generate.
Theoretically, for every 10°C increase in heat, the life of the winding insulation is cut in half. So, making sure your electric motor is running at the right temperature is the best way to extend its life.
Dust and pollution
All kinds of suspended particles in the air can enter the inside of the electric motor and produce various hazards.
Corrosive particles may wear the parts, and conductive particles may interfere with the component current.
And once the particles block the cooling channels, they can accelerate the overheating again. Obviously, choosing the right IP protection level can alleviate the problem to some extent.
Power supply problems
Harmonic currents caused by high frequency switching and pulse width modulation may lead to voltage and current distortion, overload and overheating.
This shortens the life of electric motors and components and increases long-term equipment costs.
In addition, the inrush itself can cause excessive high and low voltages.
To solve this problem, the power supply must be constantly monitored and checked.
Humidity
Humidity itself can erode electric motor components.
When moisture mixes with airborne particulate contaminants, it is even more deadly to the electric motor, further shortening the life of the pump machine.
Improper lubrication
Lubrication is a matter of degree.
Excessive lubrication or insufficient lubrication can be harmful.
Also, attention should be paid to the problem of contamination in the lubricant and whether the lubricant used is suitable for the task at hand.
All of these problems are interrelated and it is difficult to completely solve one of them by dealing with them alone.
At the same time, these problems have one thing in common: they can be prevented if the motor is used and maintained correctly and the environment is managed properly.
The following is a brief introduction:
common electric motor failures and handling methods
The electric motor is connected to the power supply to start, but the electric motor does not turn but there is a humming sound Possible reasons.
①The single-phase operation is caused by the connection problem of power supply.
②The motor is overloaded.
③ Stuck by dragging machinery.
④The rotor circuit of wire-wound motor opens into broken wire.
⑤The first end of the stator is connected in the wrong position, or there is a broken wire or short circuit.
Corresponding treatment methods.
(1) Check the power line, mainly check the wiring and fuse of the motor, whether there is any line damage.
(2) Unload the motor and start it at no load or half load.
(3) It is estimated that the fault is due to the towed equipment, unload the towed equipment and find the fault from the towed equipment.
(4) Check the engagement of brushes, slip rings and starting resistors of each contactor.
(5) It is necessary to re-determine the first and last ends of the three phases and check whether there are broken wires and short circuits in the three phase windings.
Possible reasons for the motor to heat up more than the temperature rise standard or smoke after starting.
①The power supply voltage can’t reach the standard, and the motor heats up too fast under the rated load.
②The influence of motor running environment, such as humidity and other reasons.
③Motor overload or single-phase operation.
④Motor starting fault, too much forward and reverse rotation.
Corresponding treatment methods.
(1) Adjust the motor grid voltage.
(2) Check the fan operation and strengthen the inspection of the environment to ensure the environment is suitable.
(3) Check the starting current of the motor and deal with the problem in time.
(4) Reduce the number of forward and reverse rotation of the motor, and replace the motor adapted to forward and reverse rotation in time.
Possible reasons for low insulation resistance.
①Water inside the motor, moisture.
(2) There are debris and dust on the winding.
③The winding inside the motor is aging.
Corresponding treatment methods.
(1) Drying inside the motor.
(2) Deal with the debris inside the motor.
(3) Check and restore the insulation of the lead wire or replace the insulated wire board of the junction box.
(4) Check the aging condition of the winding in time and replace the winding in time.
Possible reasons for the motor shell being charged.
①Insulation of motor lead wire or junction box insulation board.
(2) The winding end cover is in contact with the motor case.
③Motor grounding problem.
Corresponding treatment methods.
(1) Restore the insulation of the motor lead wire or replace the insulating board of the junction box.
(2) If the grounding phenomenon disappears after removing the end cover, the end cover can be installed again after adding insulation to the end of the winding.
(3) Re-grounding according to regulations.
Possible reasons for abnormal sound when the motor is running.
(1) The internal connection of the motor is wrong, causing grounding or short circuit, the current is unstable causing noise.
(2) The motor internal pump is in disrepair or there are debris inside.
Corresponding treatment method.
(1) Need to open for a comprehensive inspection.
(2) Can deal with the debris or replace the bearing room by 1/2-1/3.
Possible causes of motor vibration.
(1) The ground where the motor is installed is not level.
②The rotor inside the motor is unstable.
③The belt pulley or coupling is not balanced.
④Bending of internal rotor head.
⑤ Motor fan problem.
Corresponding treatment method.
(1) The motor needs to be installed on a smooth base to ensure balance.
(2) The rotor balance needs to be calibrated.
(3) The belt pulley or coupling should be balanced.
(4) Need to straighten the rotor shaft, set the pulley right and then set the set to re-car.
