Inpro/Seal Co. has revised its Cost Justification Worksheet (CJW) for Motors. This Excel module identifies energy and operational savings a plant can attain through the use of bearing isolators.

The CJW is a valuable tool for top management, engineering, operations, maintenance, and other professionals involved in the maintenance, repair, and operation (MRO) of motors for industrial and process applications. The elements of this module can also be used with pumps, machine tool spindles, turbines, fans, gear boxes, paper machine rolls, conveyors, shafts, VFDs, and other types of rotating equipment.

End users simply supply the number of motors, current costs to repair, and other pertinent performance data. The CJW allows plants to calculate their own ROI factoring in the use of bearing isolators, including benchmarks of current repair costs and ways to increase the reliability of their rotating equipment.

The CJW also includes such information as: accumulated savings; total investment; net return; data for life-cycle costing; the use of more efficient motors; and net costs to run motors more efficiently. The benchmarking of bearing isolator performance referenced in the CJW relies on data compiled from thousands of actual bearing isolator applications.

In his quest to find a permanent means of protecting bearings while enhancing and extending the service life of rotating equipment, David C. Orlowski developed the world’s first bearing isolator. Patented in 1977 (#4,022,479), the year Inpro/Seal was founded, the bearing isolator (a term coined by Orlowski) finally gave process plants permanent bearing protection while eliminating the need for continual maintenance.

The Inpro/Seal bearing isolator is a non-contacting labyrinth seal comprised of a unitized rotor and stator that do not contact one another. It does not consume energy, never wears out, and it can be used over and over for many years. Protected bearings have proven to run 150,000 hours (17 years) or more; bearing isolators eliminate costly maintenance and repair.

According to Orlowski, “On the plant floor, when it comes to a failed motor, the expense of the repair or replacement is, in reality, a minor cost. With process industry downtime running as high as $80,000/hr, the real cost is in the downtime, labor, loss of production, and disruption of production schedules.

“With over three decades of experience working with OEMs and end users, we know what it takes to keep motors running. We also know that contact seals, fibrous packing, flingers, lip seals, labyrinth seals, ‘sealed for life’ bearings, and other devices simply do not keep out contaminants over time. To attain the highest levels of protection and eliminate more than half of all motor breakdowns, all an end user has to do is install Inpro/Seal bearing isolators. The Cost Justification Worksheet for Motors shows how important this product can be to a plant’s bottom line.

“Protect your bearings and you’ll save your motors-–it’s as simple as that. Once installed, bearing isolators have proven to eliminate the root causes of motor failure: moisture, dirt, and abrasives contaminating the bearing environment.”

Recognizing the importance of motor bearing protection, the IEEE began to recommend the use of bearing protection and developed a specification that evolved into the IEEE motor, which offers at least twice the reliability of other motors. As part of its specification, all IEEE-841 motors incorporate Inpro/Seal bearing isolators as standard equipment. The newer NEMA premium motor, which has at least a one point energy edge, is available with Inpro/Seal bearing isolators as a standard option.

Earlier this year, Inpro/Seal unveiled its Motor Grounding Seal (MGS) and Current Diverter Ring (CDR) to deal with the damaging effects of shaft current on motors controlled by variable frequency drives (VFDs). VFD systems inherently generate residual shaft current or shaft voltage that accumulates on the rotor and discharges (shaft to frame) through the motor bearing. This random and frequent discharging is referred to as the EDM effect, a phenomenon that causes pitting on the bearing’s rolling elements and raceways and leads to destructive bearing failure.

The MGS and CDR–-an enhanced bearing isolator–-eliminate this damaging shaft current by providing a "virtual short" between the shaft and motor frame that keeps shaft current and voltage from building up before bearing damage can occur. The MGS prevents pitting, fluting, and fusion craters to eliminate catastrophic motor failure while permanently protecting bearings from contamination. Its key component, the CDR (available as a separate component) works to keep damaging shaft currents away from coupled equipment.

The free downloadable Motor Cost Justification Worksheet can be found at www.inpro-seal.com.