What are indications of an open rotor circuit in a motor?

An open rotor circuit in a motor can manifest through several distinct indicators. One of the most telling signs is a lack of torque, which occurs because the rotor is not able to generate the necessary magnetic fields required for motion. When the rotor circuit is open, the motor cannot draw sufficient current or create the magnetic induction that leads to torque production.

In addition to the lack of torque, there might be a noticeable decrease in speed. This happens because the rotor relies on an unbroken circuit to maintain its rotational speed, and when that circuit is interrupted, the rotor may stall or significantly slow down. Furthermore, the presence of growling noises can also be attributed to mechanical and electrical issues arising from the irregularities in rotor operation—often a result of electrical discharges or magnetic imbalances.

Overall, these symptoms—lack of torque, decreased speed, and distinct growling noises—effectively point to an open rotor circuit, making this combination the correct indication of the issue.