Degauss Services

The MPS 'gaussbusters'...........On-Call Services with Worldwide Coverage

SHAFT VOLTAGE TESTING: Every rotating machine has the potential to be damaged by stray shaft currents, whether mechanical or electrical. Determining the severity of these currents and the proper solutions for each rotating machine, is the focus of the Shaft Voltage Tests performed by the MPS 'gaussbusters'. MPS engineers have portable equipment to test the voltage potential on each machine to determine if and where there may be circular or stray currents. The MPS 'gaussbusters' will determine if discharging and sparking are currently present and classify shaft current and voltage sources as either electromagnetic or electrostatic in nature. Without implementing proper solutions any type of rotating machinery may be in danger of being damaged. In addition, MPS engineers perform complete and comprehensive site surveys looking for areas which may cause problems in the future, from checking grounds to tightening bolts. If appropriate, MPS ' gaussbusters' may recommend the utilization of one or more MPS Shaft Condition Monitoring or Shaft Earthing/Grounding Products to control and/or eliminate shaft currents and voltages in the future.

SYMPTOMS AND SIGNS OF DAMAGE: The most common signs of shaft current damage (sometimes referred to as electromagnetic discharge) are frosting, pitting or spark tracks on bearings, collars, journals and even shafts. This type of damage is often passed off as mechanical wear, and the typical solution is to incur the cost and replace the damaged parts. If these parts are instead repaired and sent for machining, more residual magnetism may be introduced, causing more severe damage visible only at the next shutdown.

In some machines with shaft current problems, the loss of material can be so severe that there is radial or axial movement of the shaft. Proximity probes may register high peaks caused by the presence of high magnetic fields, which can be incorrectly identified as electrical runout or as vibration harmonics. One machine vendor, after trying typical solutions, such as replacing oil, balancing, adding probes with monitoring, finally described the machine as having "mysterious mechanical damage." During MPS's many years of investigating shaft currents, no two machines have shown identical symptoms and signs. If a machine has continued problems of varying nature, shaft currents may be a factor. Shaft currents should only be ruled out after a thorough magnetic survey, and shaft voltage and current analysis have been completed.

DEGAUSSING OR DEMAGNETIZING: This process involves the systematic removal of residual magnetism in rotating machinery parts or in any ferromagnetic product by repeatedly applying magnetic fields at varying levels and polarities and in precise orientations to remove previously applied magnetic fields and residual magnetism. Proper degaussing or demagnetizing needs to be done systematically and thoroughly in an automated fashion in order for it to be effective in leaving a ferromagnetic part at an acceptable level of residual magnetism (typically 2 gauss or less), thus preventing rotating machinery damage from shaft currents. Although demagnetizing services were originally applied to rotating machinery components, the MPS 'gaussbusters' have gained tremendous experience with magnetism in general and have demagnetized just about anything you can think of. This includes degaussing of hospitals and office buildings where MRI and Laser equipment were previously installed which magnetized the buildings girders and resulted in distorted computer display screens.

We call ourselves 'experts' because MPS engineers specialize in shaft currents and focus on thorough and lasting, not temporary, solutions.

WANT TO LEARN MORE? Contact MPS and ask for an available engineer to answer your questions.