TCO: Water and Sewage UtilityMegan Thompson
Application: Flood Station Water Pump
Motor Type: Vertical AC Induction
A Midwest municipal sewage district experienced multiple winding failures on a pump motor. After repeated, costly failures from their previous vendor, the customer approached IPS for a longer term solution.
During inspection of the failed stator, IPS technicians noticed that the winding insulation had deteriorated due to overheating. IPS recommended and implemented the following solution in order to increase the reliability and life expectancy of the motor:
• Upgrade existing Class F insulation material to Class H insulation material. Class H material (e.g. magnet wire and resin) provides increased average expected life
hours at a given temperature over Class F insulation material.
• Rewind the stator utilizing VPI process and winding materials instead of a Dip & Bake rewind providing the following reliability advantages:
– VPI vacuum removes all the moisture and air from the stator eliminating potential for small voids in the slots.
– VPI rewind materials allows resin to penetrate the entire stator forming a solid, rugged protective mass improving stator mechanical strength, dielectrics and thermal transfer.
• Though the IPS Class H VPI rewind was twice the price of a competitive Class F Dip & Bake rewind, the customer has not experienced a failure since putting the motor in service over a year ago.
• By eliminating the two hours of unplanned downtime to replace the failed motor with a spare, IPSwas able to show the customer a real dollar total cost of ownership savings of $18,800 in the first year
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