Time is money. When an electric motor is out for repair it can take days, weeks, or months to get it back. What should your expectation be? What are they even doing with the motor while its gone, why does it take this long? We feel a better question to ask is:
Does a quick repair lead to the best (long-term) motor reliability?
Many times the answer to this is no. Doing something quickly versus doing something that is at the upmost quality and focused on the long-term life of the motor can many times be contradictory. Now, production can be demanding and needs something back quickly. Thats part of life in all industrial plants and facilities. However, it may be time to step back and look at things a bit differently. If you could get longer life out of the motor, would it be worth an extra day, week, month, etc?
First of all, what is truly wrong with the motor?
If you don't begin the repair process with this thought in mind then you may be running in a circle! Say the bearing failed - so you do what 99.9% of everyone else would do and replace the bearing and the motor will now run. However, WHY did that bearing fail? Was it a defect in the bearing? Its possible but in my experience, highly unlikely. Was it misaligned? Was there a balance issue in the fan? Was it not properly lubricated? Did contamination get into the bearing? Was it due to shaft currents? There are many reasons why a motor can fail. Sometime the part that acted as a fuse and caused it to be pulled is only a result of the larger issue. Doing this quickly can sometimes cause you to not stop and ask WHY - because you are to busy putting a band-aid on a wound that actually needs stitches.
What should be done to the motor while it is out?
There are quite a few processes in the motor repair industry that cannot be sped up. Oven time for example. Whenever a motor is cleaned, it needs to go through a bake cycle to remove the moisture from the winding and other components. If you do not bake it out properly, you could end up trapping moisture in the insulation system. Once motors are varnished or VPI'd (Vacuum Pressure Impregnation) they also must go through an oven cycle to cure the resin. You cannot physically work on the machine when it is in the oven for either of these cycles. They only way to speed it up is to improperly clean the motor or improperly bake it. Neither of those are good for long term reliability of the electric motor.
There are many situations in the maintenance world where speed matters. It is only reality that many times decisions have to be made based on speed. Just be sure to not run in circles by not having repairs done properly. Ask vendors about their lead times and what encompasses the lead time they have. Many times there are different process or levels of quality that are being performed. It ultimately comes down to what you feel is acceptable and what your production can live with - Just consider the questions posed in this article during your vendor selection process!
Justin T. Hatfield, CMRP
HECO - All Systems Go
About the author:
Justin T. Hatfield, 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 was instrumental in developing HECO MAPPS (Motor and Powertrain Performance Systems) which focuses on “why” you have a motor problem instead of simply “What” product or service should be recommended. Justin is a Certified Maintenance and Reliability Professional (CMRP) by the Society of Maintenance and Reliability Professionals (SMPRP). 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.