Assessing Electric Motors for Safety, Performance Following Flooding & Storm Damage
19 November 2024

ST. LOUIS, MO – Nov. 19, 2024 –Hurricanes Helene and Milton earlier this fall significantly impacted some wastewater and water treatment facilities in the Southeast, causing shutdowns and service delays. These events serve as a reminder that pump motors are a critical component of water treatment systems, and it's important for industry professionals to accurately assess potential damage to motors and determine what needs replacement and what can be repaired, before bringing their facilities back online. 

Nidec/U.S. MOTORS, a long time manufacturer of pump motors for the water industry, has issued a memorandum outlining the steps needed to evaluate motors for safety and performance after being exposed to severe weather. This includes new motors stored in warehouses that may have experienced water damage.

“Hurricanes and tropical storms continue to pose a threat to municipal plants in the South and the Gulf states,” said Dave Lyle, Vice President of Quality for Nidec/U.S. MOTORS. “This information from Nidec will be helpful for those currently dealing with rebuilding as well as those who want to be prepared for future storms.” 

While some of the obvious damage will be rusted motor shafts or contaminated bearings and lubricants, other components like the electrical insulation, when exposed even briefly to moisture, can damage the windings and result in ground failures, Lyle said. 

In addition, damage from saltwater can cause rusting of the stator and rotor cores and corrode copper windings and copper or aluminum rotor cages, leading to motor failure. Flushing and cleaning out the saltwater before the equipment dries can prevent this issue, Lyle added. 

The Nidec/U.S. MOTORS memorandum includes the following guidance. 

Motors subjected to water ingress and flooding 

WARNING / ELECTROCUTION HAZARD: Disconnect power immediately throughout any facility subjected to water / flooding ingress as there is a potential for electrocution which could result in physical injury or death whenever motors are subjected to water ingress and flooding.  Motors should not be energized and instead need to be taken to an authorized EASA motor service shop for full analysis and inspections. These analyses and inspections should include the following:  

  1. Incoming visual inspection 
  2. Incoming electrical tests 
  3. Motor(s) will be opened, and internal components and parts inspected. 

After inspection, if the motor shows signs of water ingress, the following activities need to be performed:

  • Full cleaning of all parts, internal and external 
  • Motor service shop will flush out any saltwater / moisture during cleaning process
  • Verify all mechanical dimensions are within the manufacturers design specifications
  • Replacement of the bearings 
  • Drying the wound stator by placing in oven 
  • Re-assemble the motor
  • Perform final test of the motor(s) prior to returning to the customer/end user. These tests will consist of electrical test of the winding (insulation resistance) and a test run of the motor at the shop. 

“We encourage treatment plant operators who have experienced storm damage to prioritize motors and generators for repair and replacement,” Lyle said. “Acting quickly will increase the odds that the motors can be restored for safe and efficient performance.” 

For questions pertaining to motors subjected to flooding and/or storm damage, Nidec’s Product Service Engineers can be reached at 1-800-566-1418. The service teams have decades of experience handling customer questions and providing guidance on motor operation and troubleshooting. 

Additional information on the U.S. MOTORS line for water and wastewater applications can be found at: https://acim.nidec.com/motors/usmotors/Industry-Applications/Water-and-Wastewater. Nidec has a strong inventory of in-stock replacement motors for those in need of immediate shipment. 

About Nidec Corporation, Nidec Motor Corporation and U.S. MOTORS®
Nidec Corporation is the world's No.1 comprehensive motor manufacturer. Based in Kyoto, Japan, Nidec Corporation offers motors ranging from micro-size to super large, as well as application products and services in IT, automation, home appliances, automobiles, commercial and industrial systems, environmental, energy, and many other businesses. Nidec is comprised of approximately 340 companies employing more than 110,000 people all over the world. www.Nidec.com

Nidec Appliance, Commercial and Industrial Motors (ACIM) is a Nidec Corporation business unit that includes three Platforms: Global Appliance (GA), U.S. Motors (USM), and Commercial & Industrial (C&I). With over 18,000 employees and 37 manufacturing sites in 25 countries, ACIM is one of the largest divisions in terms of sales inside Nidec Group. ACIM has a vast portfolio that covers compressors, condensing units, and motors for residential and commercial appliances, as well as motors and electronic drives for commercial, residential, industrial, and utilities applications.  This comprehensive set of solutions is characterized by high standards of quality and energy efficiency, delivering innovation and sustainability across ACIM's broad customer base.   

The U.S. MOTORS® brand encompasses a complete line of general and special purpose commercial and industrial motors from 1/30 horsepower through 4000 horsepower for a wide variety of applications. Since 1908, the U.S. MOTORS brand has stood for exceptional product reliability and performance. It is one of the oldest and most trusted brands in the motor industry and is recognized worldwide as the mark of leadership and technological innovation. www.USMotors.com.