Early detection of broken rotor bars is essential to keeping a machine from having to undergo costly repairs. Often, a machine with a broken bar will keep working, making it hard to know when it’s time for repairs.
If there are multiple broken rods, it can lead to machines not starting and is a sign that there is deterioration of other parts. This deterioration can lead to expensive repairs, so it’s better to recognize the problem and fix it as soon as possible.
What causes broken bars though, and how can you fix them? Read on to find out!
Causes of Broken Bars
There are many causes for broken bars. One of the most common, of course, is natural degradation. Everything breaks down eventually, especially when used in machines.
Another reason for breakage is using a machine for anything other than its intended purpose. Always follow the manual and safety precautions.
Thermal overload and cracks due to high temperatures are additional causes. Always make sure your relay is working to prevent any fires in equipment.
Signs Your May Have Broken Rotor Bars
Often, the only way to discover if there is a problem is through testing. The most common and accurate method is the Current Spectrum Test.
The stator windings receive currents induced by the rotor. Around the supply line frequency peak, which is 60Hz, the currents show up as side bands.
The currents are a function of the motor’s number of poles and slip frequency (slip speed X p / 120). A technician can look at the frequency peak and sideband amplitudes and tell how many broken bars there are.
Single phase, high current, and vibration spectrum analysis are other common tests. The type of test you’ll need is dependant upon your equipment type and the motor.
If you think that you might have a problem with your rotor bars, you should get them tested right away. If not, it could lead to sparking, wear of bearings, or motor core damage. These potential problems are more expensive than getting a test done.
Rotor repairs are not something to take lightly. There are too many things that could go wrong, and improper repair can lead to a much bigger issue. There is no need to risk productivity by having a machine shut down longer than necessary.
The best course of action is to let experienced professionals handle it. Your equipment and your people will be safer. Industrial and commercial accidents happen often and can have life changing consequences.
We Are the Experienced Team You Need
We’ve been repairing rotor bars since 1974. No matter what type of problem you have, we’ve seen it before.
We’re confident in our ability to get your machines up and running again. You don’t have to take our word for it; we have examples of our work online for you to see!
We look forward to hearing from you!