Q: Can you tell us about your warranties and maintenance?
A: From a warranty perspective, we do not differentiate between low voltage or medium voltage. We are comfortable with our motor repair services so our warranty remains the same for the two. You get up to 6 months on the shelf, and a year in service regardless of large motor or large generator ratings. The only exception to this was for a short term, there were some manufacturers that were making random wound equipment in medium voltage, and they were only doing so in a 2,300 volt class. OEM’s really pushed the design envelope making those motors notoriously difficult to repair. With increased voltage, there is an increased requirement to contain that voltage, and that is where that added insulation materials come into play. Advances in insulation material technology has allowed for more reliable repairs. From a maintenance standpoint, cleanliness is key. Routine inspections of your large industrial motors, if they are dirty then they need to be cleaned, whether it is a simple blow down or inspection, and routine electrical testing can help indicate when you have a cleanliness problem. You can also use this data as predictive maintenance in scheduling outages or inspections on site before removing for repair overhaul. This would be even more so with these types of large motors and applications. The higher the voltage rating goes, the lower the current rating, and while you increase efficiency, you also increase the need for more insulation to contain that voltage or pressure that is continuously trying to escape.
Q: What is the relationship between the footprint of the equipment, the voltage rating and horsepower rating?
A: The driving factor behind the footprint is torque output. You could have a 100 HP large motor that is rated for 1,800 RPM, that’s 300 pound-feet of torque. If we change the speed rating on that motor down to 300 RPM, with the same 100 HP motor, then it can produce almost 1,800 pound-feet of torque. With that, mechanical load requires more mechanical structure. The speed rating and torque output is what drives the footprint of a motor.
Q: Anything else you would like to add, Adam?
A: I would strongly recommend routine inspections, cleaning, vibration monitoring, and electrical testing as part of predictive maintenance which are key to a long-lasting motor.