Electric motors usually serve as an essential component for any facility. However, just like any other machine, electric motors are not immune to failures. They can face a couple of issues that can lead to motor faults. When this happens, not only will business operations be disrupted, but productivity and profit will also be adversely affected.
Meanwhile, some failures cannot be avoided because everything has a limited lifespan; but a great majority of AC electric motor failures are also preventable. Winding failures, particularly, can be effectively prevented with proper maintenance and repaired through electric motor rewinds.
Below are the major types of electric motor failures you should be aware of.
1. Electrical failures
Electrical failures are some of the most common types of issues that can disrupt the operations of AC electric motors. These failures are typically caused by winding insulation problems. They can be in the form of phase to phase, turn to turn, coil to coil, coil to ground, and open circuits.
To troubleshoot electrical issues in AC electric motors, a ScopeMeter and power quality sensor can be used to analyse electronic harmonics, distortion, and load studies.
Moreover, it is possible to utilise a motor and insulation tester to ensure safe operation and extend the life of your electrical systems and motors. This device identifies motor speed, torque, motor insulation degradation, and others.
2. Mechanical failures
Other common rewinding failures in electric motors may stem from mechanical failures.
These faults usually take the form of coil movement where the coil moves and risks damaging the winding as a result of being poorly blocked or braced. Aside from coil movement, mechanical failures may also arise when there abrasion in the stator and rotor occurs as a result of being rubbed against each other.
To diagnose mechanical failures, vibration and alignment tools are the best technology to use because they can determine proper shaft alignment, misalignment, bearings, imbalances, and looseness.
3. Thermal issues
In an electric motor failure, temperature commonly plays a critical role.
As a matter of fact, according to research, the lifespan of a motor is inversely related to temperature. The hotter the motor runs, the faster it is going to fail. Usually, the temperature of your electric motor can rise if it operates beyond the limits of its design. Voltage variations and voltage imbalance can also make your motor’s winding temperature higher than normal.
To find electric hot spots in your machine’s switchgear and motor controllers, it is highly recommended to use infrared imagers. These devices are useful for mechanical assets and screening process – they can examine faulty connections, tank levels, and overheated bearings.
4. Environmental stress
Aside from high temperature, moisture can also cause a major problem for electric motors.
Moisture can form either through a general equipment wash down, a buildup of condensation, or an incredibly humid environment. Nonetheless, no matter what the cause is, moisture can result in a range of winding issues like shorts.
To avoid environmentally induced electric motor failures, make sure not to expose your motor and its winding to abrasive particles like sand and cement dust. Always check for a buildup of dust and debris on the motor as well, as this can create a significant problem by making it difficult for some component to conduct heat away from the motor.
There are plenty of failures that can happen to the winding of an AC electric motor. By knowing what these major failures are, you can prevent or repair your electric motor in the most proper and efficient way.
