Rotor bars are components of electric motors typically made from copper, aluminum, or brass. They interact with the radial flux wave to produce the motor’s driving torque. While electric motor maintenance technicians can officially diagnose and address the issue, here’s what you should know about rotor bar cracks to prepare for an informed conversation.  

What Happens When Your Rotor Bar Is Cracked?

Because motor bars create torque, it’s possible a crack will prevent a motor from running entirely. Yet, a single broken motor bar won’t always cause an immediate failure, particularly in large, slow-speed motors. In this case, issues may not develop until several rotor bars crack.

Yet, left unaddressed, compromised motor bars can cause problems like sparking, as well as torque and speed oscillations which can prematurely wear away bearings and other motor components.  

What Causes Rotor Bar Cracks?

Because rotor bars sustain friction, they may experience natural wear and tear over time. Routinely receiving electric motor maintenance can help keep this issue at bay.

The high temperatures they are exposed to can also cause cracks since metal expands when heated. Finally, one damaged bar can set off a chain reaction in which nearby bars become cracked by altering the motor’s current production or heat generation.

How Can You Tell If Your Rotor Bar Is Cracked?

In addition to scheduling routine inspections, you can also perform tests to detect a problem with your rotor bars. Electrical devices known as growlers can be placed on a heated rotor to test for shorts in coils. You can also use an analog meter to watch for changes in amperage draw when the motor is run at a slow pace. Alternatively, you can apply a high current to the motor shaft and look for shorts. 

Whether you suspect you could have a cracked rotor bar or you simply need routine electric motor maintenance, turn to United Electric Motors. Serving the Anchorage, AK, community, this company has more than two decades of experience and is made up of skilled technicians who offer 24/7 support. Call (907) 563-5232 to speak with one of their experts. Visit their website to learn more about their offerings.