When you think about the processes you have in place at your facility that are designed to keep the operation running, the first thing that comes to mind is most likely the PM schedule. You go around monthly or so and check filters, oil levels, temperatures and other detectable signs of easy to remedy issues that are bound to arise. Beyond that, maybe you have a quarterly vibration route and are collecting data on the health of your machines. Usually, this data is worth the cost of the program when it is able to predict an impending failure that can then be repaired before it breaks down catastrophically. This is a solid cost savings and can be easily justified.
Motor management is another layer to this that should be looked at in more detail as the cost savings are equal to the above and at times can be more immediately realized.
Think about where your spare motors are stored now? Are they sitting on the ground next to the live equipment with an overhead pipe leaking and constant vibration destroying the bearings? (I've seen it). Or do you have a climate controlled warehouse with everything neatly arranged by frame size with a PM schedule that rotates shafts and megs the motors? One of these scenarios is much more likely to produce a viable spare at a critical moment.
Programs like these are completely scalable for just about every facility type. What you should expect at a minimum is a database of all motors in your plant and to perform a critical assessment to determine what motors are truly needed and in what quantities to maintain operations in the event of a failure. Eliminating unnecessary inventory is an immediate cost cutting tool that should be a part of any management program.
Once you have a good idea of what your spares inventory should look like, you can then decide which approach would make the most sense for your plant. The spectrum runs from staffed warehouse performing checks for you, handling repair situations, qualifying returned repairs and transportation, to someone coming through and data-basing your inventory for reference. What motor management is not, is simple warehousing, that's just storage and provides no guarantee of viability and little data. Motor management done appropriately is an active operation. Passive programs like warehousing provide some value over alternatives, but should not be confused with a living asset management program.
Let's imagine two scenarios where a failure occurs:
Plant ABC has run into a bit of trouble with a crane motor. Overnight the motor blew it's winding and took down the main product crane and now they're losing money every minute production is down. Knowing that this crane motor is critical to their operation they have a spare on site for situations just like this one. The maintenance crew grabs the motor from the next building over and gets it installed, sends the blown unit out for repair, and they're back in production. The repair is a rewind requiring some unique alloy so the lead time is out to about 45 days, unfortunately after just 9 days the spare unit has a bearing failure and wipes out as well. Now there is a mad scramble to get something done quickly... you can imagine the rest.
Plant XYZ runs into the same problem, but this time, the maintenance crew calls the warehouse manager and lets him know that he needs the spare ASAP. Within 90 minutes the spare unit is delivered and the blown unit taken to be sent off for repair. This spare has been megged, shaft rotated at regular intervals, and had a previous repair validated to ensure it's reliability. Around 45 days later the original blown unit is returned to the warehouse and is inspected like the previous and will sit safely on the shelf until it's needed.
If the first scenario is more recognizable, it may be beneficial to explore motor management options for your facility. The peace of mind that comes from confidence in your motors ability to perform when they're needed absolutely outweighs the stress of not knowing and figuring it out when it's too late.
Justin T. Hatfield, CRL, CMRP
HECO - All Systems Go
About the author:
Justin T. Hatfield, CRL, CMRP is the President at HECO - All Systems Go. He is responsible for Electric Motor & Drive Sales, Electric Motor & Generator Repairs, Spare Solutions, and Predictive Services. Justin is a Certified Maintenance and Reliability Professional (CMRP) by the Society of Maintenance and Reliability Professionals (SMRP). HECO is an EASA Accredited Service Center for Electric Motors as well as a provider of predictive maintenance & reliability services and products throughout the United States.