SPM Bearing Monitoring
Increasing numbers of customers are starting to use the condition monitoring method. This means that the time of maintenance depends on the condition of the motor and not on the number of working hours or other measures. In order to use this method, the suitable testing equipment with which the various magnitudes which define this condition can be determined, need to be available. There are a number of different methods used to establish the condition of the bearings whilst in operation. The best known method is the SPM method (Shock Pulse Monitoring method). High-frequency shocks that occur in bearings when rolling elements and races come into contact, are translated by a detection system into an instrument monitoring the bearing condition. The place where an SPM nipple can be positioned is very important for correct measuring results. The fitting of the SPM nipples must also meet specific criteria. We recommend having the SPM nipples or detectors fitted on the new electric motors by qualified professionals to ensure that these criteria are met. The rotor nl® electric motors can be supplied with SPM measuring nipples or detectors as an option at a surcharge
Mechanical Vibrations & Balancing
All rotor nl® electric motors are dynamically balanced with half key in accordance with the IEC 34-14 (2003) standard. The letter H (for Half key) is specified on the rating plate and on the shaft end as a sign the motor was balanced with a halve key. The letter F (for Full key) means that balancing has taken place with the full key.
It is important that the parts or equipment that are mounted on the motor shaft are balanced accordingly before fitting. The maximum permissible vibrations of electric motors are defined in the IEC 34-14 standard. The rotor nl® electric motors meet the vibration class A as standard. It may be a customer requirement to reduce motor vibrations for specific applications. Rotor nl® electric motors can be supplied in the reduced vibration execution of class B (special) upon request.