Hysteresis Brake and Clutch FAQ

Below is a list of frequently asked questions regarding Magtrol’s Hysteresis Brakes and Clutches. Should you need further assistance, contact Magtrol or your local sales agent.

Q: I am searching for information on a Magtrol hysteresis brake that I currently have but the model number does not appear on the ratings and dimension tables. Does it still exist?

Magtrol has consolidated its lines of brakes so that the corresponding hysteresis brakes, matched brakes and metric brakes all have the same ratings and model numbers. Please refer to the table below to find the new model number that replaced your existing brake. In most cases, the older model can still be ordered if necessary. Contact Magtrol Brake and Clutch Sales for more information.

Old Model #Replaced By

Q: How do you reduce the cogging effect on Magtrol hysteresis brakes?

It is important to note that the presence of cogging torque does not represent a defective hysteresis brake or clutch. It is part of the hysteresis technology and is due to the residual polarization of the rotor material. In order to minimize the cogging effect (especially after shut down), follow these steps:

  1. Before switching off the installation, slightly rotate the brake shaft by hand (clockwise or counter-clockwise).
  2. Energize the brakes to full current then decrease gradually to 0.
  3. Turn off the power to the coil.

For more information regarding cogging and its effect on hysteresis devices, refer to Section 7.0 of Magtrol’s Hysteresis Brake and Clutch user’s manual.

Q: Can I exceed the maximum speed for a hysteresis brake?

There is some safety factor for exceeding speed specifications however, it is not recommended. High speeds require better balancing, better bearings, tighter tolerances, better couplings, etc. High speed versions are available upon request. Contact Magtrol with your application details, maximum torque, and maximum speed.