積極的なモーターテストがエタノール工場を守る

Ethanol is a clean-burning fuel that has been used in the United States since the 1850s. Ford’s Model T automobile was designed to run on ethanol, and although ethanol was banned during Prohibition, it became popular in the 1970s when gasoline prices rose and oil imports became a concern. Ethanol experienced a major resurgence when Congress initiated the Renewable Fuel Standard in 2005, which sets minimum requirements for the use of renewable fuels; today, approximately 14 billion gallons of ethanol are added to gasoline consumed nationwide annually.

 

Company Profile

One company contributing to America’s renewable energy sources is Cardinal Ethanol, which opened a natural gas-fired ethanol plant in the heart of the Corn Belt in 2008. The Indiana ethanol plant produces approximately 100 million gallons of ethanol annually and also produces 340,000 tons of dried distillers grains with solubles, which are sold to companies that produce livestock and poultry feed.

 

application

To produce 100 million gallons of ethanol per year, the plant’s equipment must operate reliably 24 hours a day, seven days a week. The ethanol plant’s in-house maintenance team schedules “planned shutdowns” twice a year, in the spring and fall, to maintain the plant’s equipment and machinery. During the fall 2015 shutdown, four new motors were installed to drive the conveyor belts that transport corn to the ethanol processing plant.

In December 2015, the maintenance team noticed a disruption in grain flow. Mark Durr, the ethanol plant’s maintenance project manager, quickly investigated the grain handling system and determined that the interruption was caused by intermittent conveyor stalls. Mark then instructed the in-house maintenance team to perform several tests on all four motors that drive the corn conveyors.

“I had a technician test four motors ranging from 40 to 60 horsepower, and the megohmmeter showed no coil problems, no short turns, and no current to ground,” Mark explains. “When I used the ALL-TEST PRO 33 IND™, the motor tester indicated the rotors were bad.

 

Test Results

Mark immediately contacted the general contractor who installed the motors and told them what he had found. The contractor was intrigued by Mark’s conclusion that the rotors were the problem. The motors were brand new, and the contractor couldn’t believe that all four motors had rotor issues. When asked how he had come to the conclusion that the rotors were the root cause of the problem, Mark explained to the contractor that he had an AT33™ Unpowered Motor Tester, which provided a complete view of the condition of both the stator windings and the rotor.

“We purchased the AT33™ Motor Tester shortly after I started working here. We place a lot of emphasis on preventative maintenance to keep this plant running, and that means having the right tools to prevent a plant shutdown,” said Dr. S. “If there’s a problem with the motor, a megohmmeter, a multimeter, or an LCR meter (L – inductance, C – capacitance, R – resistance) won’t tell you if the rotor is the problem, but the AT33™ will.”

After the motor test results were shared with the contractor, the contractor arranged for the motor to be replaced, as it was still under warranty. The motor tested with the AT33™ was sent to the contractor’s service center for an overhaul. The service center technicians confirmed that the rotor was the root cause of the motor’s inability to perform as intended.

“The report from the service center confirming the rotor was faulty came as no surprise to me,” Mark says, “because we know that standard testers don’t have the capability to indicate rotor health. That was one of the main reasons we purchased the AT33™; in this case, it really helped.”

 

conclusion

Motors should be tested before installation

It is very important to inspect new or stored motors before installing them in your system. Taking a few minutes to test a motor before installing it can save thousands of dollars in maintenance and potentially outage costs.

Performing both static and dynamic tests, the AT33™ De-energized Motor Test Instrument is a proven asset for revealing the complete condition of a motor’s rotor and stator windings, while also helping maintenance technicians and operators understand if there are any contamination, connection or ground fault issues.

 

About ALL-TEST Pro, LLC

ALL-TEST Pro delivers true motor maintenance and troubleshooting with innovative diagnostic tools, software and support.

 

About Cardinal Ethanol

Originally founded by 12 members in Randolph County, Indiana, the Cardinal Ethanol Project was formally organized in February 2005 with the objective of planning, constructing, and operating a 100 million gallon dry mill corn processing plant that would benefit investors, farmers, and the local community.