High-voltage motors drive critical equipment such as pumps, fans, compressors, and mills. When one fails, the cost of downtime usually far exceeds the cost of the motor itself. So is vibration monitoring worth adding? For critical equipment, we consider it a standard feature. For most other industrial applications, we strongly recommend it.
Why Vibration?
Most common motor faults show up in vibration first, before they appear as heat, noise, or a trip. These include bearing wear, rotor unbalance, misalignment, loose foundations, and broken rotor bars. Temperature and current monitoring alone tend to catch these problems later. Vibration monitoring gives you time to plan maintenance instead of reacting to a breakdown.
When We Recommend It
Critical equipment with no standby unit
Large, high-speed motors
Motors with sleeve (journal) bearings
Harsh or variable duty, such as frequent starts or VFD operation
Remote or unmanned sites
Hazardous areas where manual inspection is difficult
Choosing the Right Solution
Rolling bearing motors: Casing-mounted accelerometers or velocity sensors, combined with bearing temperature monitoring, are usually sufficient.
Sleeve bearing and large motors: Proximity probes measure shaft vibration directly and are the better choice for important machines.
Alarm and trip: Start with alarm levels, then add trip functions once operating experience is established, to avoid false shutdowns.
Hazardous areas: Sensors and cables must match the motor’s explosion-protection rating. Please specify them at the order stage so the motor can be supplied with mounting provisions, rather than drilling on site.
For evaluation, IEC 60034-14 and ISO 20816-3 are commonly referenced, along with the equipment supplier’s requirements.
The Bottom Line
The cost of a monitoring system is small compared with the motor and with the cost of unplanned downtime. It reduces consequential damage, extends bearing life, and provides data for condition-based maintenance.
If your motor is critical, high-power, sleeve-bearing, or installed in a hazardous area, we recommend including vibration and bearing temperature monitoring in the technical specification from the start. Contact our team to discuss the configuration that suits your application.
