There are electric motors and then there are electric motors. On my recent trip about an hour south to the Siemens electric motor manufacturing plant in Norwood, OH (a suburb of Cincinnati) I was often thinking about the line from Crocodile Dundee when the main character pulled out that child of a sword and Bowie knife and said, “Knife? That ain’t no knife. This is a knife.” When we start talking Medium Voltage motors at greater than 10,000 HP, that’s a motor.
Note: the one in red is a motor under test. Note the size versus the size of the person.
I’ve visited the plant a time or two before but wrote the news for magazines. Only a mention on my blog. When I was there in 2012, they talked about the transformation of the plant from a traditional old-school heavy manufacturing plant to a modern, lean, clean place to work putting out quality products.
The occasion for this visit was to view results of some significant investments by Siemens in maintaining Norwood as a state-of-the-art motor manufacturing plant. There are several new machines for precision machining of large parts. The pièce de résistance however was a new test bed and “Test Center Observatory” where customers can witness the testing of their motors in comfort with a dedicated Ethernet connection so that they can continue working during downtimes in the test process. A complete test regimen can last for several hours or even longer. Some customers come from other countries. Speaking as someone with experience traveling to witness tests on my products for certification, I’d have really appreciated this facility back in the day.
Before I get to the test bed, a brief discussion of digitalization and vibration.
Siemens has developed a digitalization methodology for motors called Drive Train Analytics. They are sensoring more and more in order to monitor and analyze a more complete virtual picture of the motor. Not surprisingly, they use Siemens Mindsphere sending data to the cloud using a variety of analysis tools. Customers have access to these tools in the observatory. Actually, customers could receive a complete virtual runoff of their motor back home. But engineers being engineers, they love to see the hardware in person. So they get both.
Aside from heat, the main killer of motors is vibration. Siemens has taken steps both to reduce vibration in the motor and to reduce ambient vibrations in the test process so that more accurate readings of the motor itself.
Working with customers who provide feedback from their use cases, Siemens developed a new shaft requiring new machining techniques. Some of the advantages of the new shaft include:
- Eliminates variation due to fabrication and spider bar tolerances
- Reduces required balance weight applied during rotor balance
- Removes heat-treatment process
- Improves rotor thermal stability
- More predictable rotor lateral stiffness
- Reduces stress concentration of weldment
The News-Test Observatory
With its celebration of more than 120 years of innovation, market and product leadership, technology and quality, Siemens’ Norwood Motor Manufacturing plant recently opened a new Test Observatory.
Opened in 1898, the Norwood facility has undergone a century of change, as the process to manufacture motors and the technology behind them has improved. Norwood has stood the test of time through three industrial revolutions and is one of the longest continuously operating Siemens’ plants globally. With Industry 4.0 upon us, the mechanical motor of old is now a connected device, a valuable plant floor asset capable of providing vast amounts of data with preventative and predictive analytics to ensure more productivity, efficiency and uptime.
With the largest motor test base in North America, Siemens can combine its century of industry leadership in motor manufacturing with an enhanced customer experience. The new equipment extends Norwood’s testing range from 10,000 horsepower (HP) to 20,000 HP at frequencies from 10 Hz to 300 Hz, thus addressing the market’s increased use of variable frequency drives. The new test observatory, akin to an executive suite, allows customers to participate by observing testing through bay windows, direct cameras and mirroring computers, which display real time critical data being gathered by sensors attached to their motor.
The project, which began in 2016, required the removal of 550 tons of soil and concrete from the site, excavating a 13-foot deep hole, driving 114 pilings for stability and building a huge concrete vault to securely support a fully loaded test stand. The test stand weighs 360 tons and rests on a self-leveling air spring system designed to support 500 tons when loaded with motors and drives.
The testing equipment includes two Sinamics Perfect Harmony GH180 drives and two dynamometers. Generating power to test a 20,000 HP motor requires significant amounts of electricity, and by recycling power to the grid, the new equipment reduces power loss by 90 percent.
“At Norwood, we test every motor that we produce or repair – some 30 to 50 tests per week – and these new facilities give us the ability to conduct as many as five motor tests at a time.” said Tim Bleidorn, Manager, Manufacturing Excellence. “We expect the customer witness tests to average two to three per week and as many as 120 per year.”
In addition to the new test base and observatory, the multi-million dollar investment in Norwood also includes WFL high-precision shaft making equipment and a high-speed balancer, key for two-pole applications at higher speeds and the ability to balance a rotor at up to 12,000 rpm.
“It’s exciting and I’m proud that Siemens is investing in the North American market. We have the No. 1 market share in AboveNEMA motors right now and these new capabilities send a strong signal to our customers and competitors that we intend to maintain that position,” says Ryan Maynus, AboveNEMA Product Manager.
With more than 100 patents, the 350,000 square-foot facility is a cornerstone to Siemens AboveNEMA motors. The ISO-9001 certified plant has produced more than 150,000 high voltage motors since 1898. The Norwood plant produces horizontal AC induction motors up to 20,000 horsepower and voltage ranges from 460 to 13,200 volts. The plant also manufactures a complete line of large AC vertical motors up to 8,000 horsepower.