Common Causes of Electric Motor Failures

Electric motors are employed in nearly all commercial and industrial operations, and they account for a large chunk of Canada’s electricity usage. They drive compressors, fans, conveyors, elevators and more. Naturally, motor failures can have serious consequences, so it’s important to understand the common causes of such failures.

Motor overloads

About 30% of motor failures are due to overloading, which happens whenever a motor is made to provide more power than it’s rated for. When a motor is overloaded, it produces more heat than it can handle. Excessive heat degrades the motor’s insulation, which in turn causes shorts. Therefore, higher temperatures mean quicker degradation of the motor’s lifespan.

Over cycling

Also known as short cycling, over cycling occur when a motor that’s already up to working temperature is turned off and turned back on before it can cool down. Doing

this increases the temperature of the motor, which can damage the motor’s insulation and lead to a breakdown. Most manufacturers indicate the maximum number of times a motor can be turned on in the same hour and it’s important to comply with those guidelines.

Power supply issues

Power surges and voltage unbalances are common causes of motor failures. When a motor draws more power than it’s designed for, or when a surge in the power supply forces an abnormally high voltage through the motor, it causes the motor to overheat. The worst kind of voltage unbalance is what’s called single-phasing, which occurs when a motor designed to run on three phases runs on two phases. Such motors can still run on two phases by drawing more current on the remaining phases, which leads to

higher heat and thus a shorter lifespan. Moreover, single-phasing is hard to detect, which is why it’s best to have a technician take a look at your motors.

Environmental factors and mechanical failures

There are a host of environmental factors that can cause motor failure. Poor ventilation will lead to overheating quite quickly, and if the motor is completely enclosed, moisture can cause rust to appear. Keeping the motor lubricated is important, but over-lubrication can cause grease to enter the windings. Finally, the most common mechanical causes of motor failure, improper belt tension, misalignment and vibration, may be difficult to identify without professional help.

Electric motor repair in Lethbridge

Given how serious motor failures can be, it’s important to be on the lookout for signs they’re malfunctioning. It’s also crucial to know who to call if you require help. If

you need someone to look at your electric motors in Lethbridge, contact us at Southern Rewind. Our technicians can help with everything from checkups to emergency repairs.