Reliability is foundational to the Central Arizona Project system. From preventive maintenance and repairs to upgrades and replacements, the focus is always on reliability – and the motor rotor pole replacement project at Mark Wilmer Pumping Plant was no exception.
Centralized Maintenance and Reliability Director Phil Rettinger said that the poles were manufactured in sets; however, each individual pole has a slightly different weight. The result was that some sets exhibited a higher level of mass unbalance than others.
“We noticed higher levels of vibration, which is problematic for the long-term reliability and operation in these high-powered pumps,” said Rettinger.
The standard procedure for addressing issues like this on large rotating elements is to send the work off site for a dynamic balancing of the rotating element. However, given the immense size of the equipment at Mark Wilmer – the pumps are 66,000 horsepower – extensive disassembly would be required to send them, which made that option less than ideal.
Fortunately, CAP has experts who analyzed the situation and found the most effective path forward – field balancing.
Rettinger said field balancing requires minimal disassembly and is a combination of low-tech and high-tech solutions. Weights are added to the rotating element in specific locations based upon vibration data gathered during test runs of the motor. The vibration tests are then repeated as the iterative process continues until balance is achieved.
“We added almost 80 pounds of weight to correct Unit 2,” said Rettinger. “The process went smoothly, thanks to extensive pre-planning and preparation, which enabled us to achieve the desired results – minimizing the risk to the unit’s long-term health and ensuring continued operation.”
The result? The team was able to see overall vibration levels drop from approximately 15 mils to 5 mils, or a 66% reduction. Rettinger said that Unit 2 is now one of the best running units based on vibration!
“Great results come from a great team that won’t settle for the status quo or good enough,” said Rettinger. “We always strive for reliability from effort, expertise and precision maintenance.”
KRA: Project Reliability
Providing reliable and cost-effective operations, maintenance, and replacement of CAP infrastructure and technology assets