3 Signs Your Rotors Are Damaged

Close-up, selective focus of electric motor rotor

An issue or a failure in an electric motor can happen for several reasons. Many of these issues often occur during the motor startup phase because of over-currents or low insulation resistance, but there are other problems that can happen during the motor’s operation due to problems from a lack of maintenance or even internal damage. This forces forcing the owner to consider either repair or replacement of the motor.

Although many motors have a long service life, they require regular inspections in order to catch and identify any signs of aging or potential fault as quickly as possible. This is particularly true when examining motor parts like the rotors, which are often the components that are under the most stress. Below are a few signs you should watch out for that could indicate potential damage to the rotors in your motor.

1. Excessive Vibration

Electric motors cause some noise and vibration when they are running at high performance. However, if the vibration is more than normal and escalates to something excessive, this is a clear sign that something isn’t right with the motor.

Physical damage around and to the rotors of an electric motor can occur when when an emergency fix or routine maintenance is performed. For instance, you might discover a problem after replacing a bearing or disassembling and reassembling your motor. These processes can lead to an imbalance in motor performance and cause rotor damage.

Imbalanced motors are a common issue, and this imbalance can place extra stress on the motor bearings within the motor. This stress could lead to your rotor connecting with the stator, thus prompting another failure. The key to avoiding this problem is to make sure that you only trust a team of professionals to perform repairs and rebuilds.

2. Complete Failure

A rotor consists of several layers of laminated steel, and each winding on the rotor features bars made of aluminum alloy or copper, which are balanced by shorting rings. Each of these components are essential to the performance of your rotor and, therefore, electric motor. But each piece can cause problems like thermal stress, imbalance, and contamination.

For instance, if your motor suddenly stops working (and seemingly without reason), this could be a sign that something inside your motor isn’t right. And one of the root causes of this can be moisture. Rotors can be particularly susceptible to moisture, especially in AC motors. When moisture or humidity levels are too high in a specific environment, this can lead to corrosion of the bearings, the shaft, and even the rotor, too. This then leads to problems with decreased efficiency and minimal rotation, causing your motor to suffer and underperform.

3. Scratches on Rotor Bars

If you suspect that something isn’t quite right with your motor, one of the best ways to find the source of the problem will be to ask an expert to examine the internal elements. If scratches appear on the rotor bars on your machine, this could lead to problems with the magnetic field, which will affect the performance of the motor.

Our repair staff at Sloan Electric can help you by entirely removing the rotor from the machine and either visually inspect the bars or use special components (like dyes) to detect any breaks or cracks in the bars that might be reducing performance. If fractures in the rotor are hard to detect, discoloration around the core of the rotor is a potential indicator that the bars of the rotor may have started to break down.

In select cases, professionals can perform a single-phase test for rotor damage while the rotor is still connected to the motor. This process involves powering the motor as the rotor slowly turns, then monitoring for dips in the stator current, which can indicate any potential cracks.

Finding the Source of Motor Failure

There isn’t a “one-size-fits-all” method for effectively tracking and preventing damage to an electric motor. If you’re concerned that there might be a problem with your rotors because of severe vibration or diminishing performance, the best thing you can do is talk to a professional technician and ask them to thoroughly inspect the motor’s components to get to the root of the problem.

Our professionals at Sloan Electric can guide you through the complexities of finding and repairing the problem as quickly and effectively as possible. This means that we can help you keep your downtime to a minimum and protect your investments in the process.


3 Signs Your Rotors Are Damaged was last modified: March 2nd, 2018 by admin

About admin

Jerry is the owner of Sloan Electromechanical and is active in all aspects of the company. He is passionate about doing the work RIGHT and proposing the best product solution, hence the Sloan team is focused on aligning company values with client values. Please post your questions or comments and Jerry will respond. For a faster or confidential response, please contact Jerry directly 619-515-9691 or LinkedIn www.linkedin.com/pub/jerry-gray/17/332/5a1
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