Unplanned motor downtime is a costly show-stopper. Inadequate motor efficiency also harms the bottom line. Both conditions are avoidable with the right equipment and processes, and fortunately, those options are improving. A new regulatory standard raises the bar for motor efficiency. Innovations in motor-system design and testing are improving reliability and performance. Professional motor training and repair services close the loop in effective motor management.
Extended efficiency targets
New U.S. Department of Energy (DOE) regulations effective June 1, 2016, require motor manufacturers to comply with National Electrical Manufacturers’ Association (NEMA) premium efficiency targets for electric motors with a 1- to 200-hp rating, says Chip McDaniel, educational specialist at AutomationDirect. “The new standard closes loopholes and extends coverage to a new list of motors not previously covered,” he says.
There will be a timeframe in which both the older and the newer types of motors likely will be sold. If efficiency is a concern, it may be prudent to check on the efficiency level of a given motor prior to purchase, advises McDaniel.
Advanced system design
Electric motor manufacturers are finding new ways to increase performance and reliability. For example, the Baldor-Reliance RPM PD Direct Current (DC) motor series achieves this with innovative DC motor technology.
“An optimized armature design produces full power over extended speed ranges with smooth torque transitions when run at very low speeds,” explains Marcus Orders, global product manager for DC motors at Baldor Electric Company. “Maintenance is also simplified in the DC motor utilizing standard length brushes and a mechanical system to monitor brush wear and change out brushes at scheduled maintenance intervals.”
Michael Offik, director of packaged solutions at ABB, believes the convergence of cloud computing with smartphones, tablets, micro-electrical-mechanical systems (MEMS), and wireless communications, allows for a new level of Internet of Things (IoT) products. Incorporating smart devices such as compact, intelligent sensors in motor system designs improves control over vibration, temperature, and other parameters that affect downtime, energy consumption, and motor life.
“ABB’s new Smart Sensor for low-voltage motors brings users into the IoT to now include useful services that allow people to make informed decision and take action,” says Offik.
Precision motor testing
Low-voltage motor failures happen early if variable-speed drives and inverter drives are misapplied, says Jacob Beck, CEO at Electrom Instruments. “We have developed automatic partial discharge [PD] measurements that find PD, can provide early warning of problems to come, and identify issues with inverter drive systems. In low-voltage motors, there should be no PD,” he explains. Electrom Instruments offers a range of motor, generator, and coil-testing products for manufacturers and industrial users.
Electric motor test equipment and software offering onboard automated analytics for the technician, integrated with remote data analytics for feedback from the analyst, is the key to a successful reliability program, believes Noah Bethel, vice president of product development at PdMA Corporation. PdMA offers portable static, dynamic, and combination motor testers that trend the condition of AC induction, synchronous, wound rotor, and DC motors and their circuits.
For predictive maintenance and troubleshooting, All-Test Pro offers portable instruments that identify electrical issues in motors before they stop working. Conditions detected include turn-to-turn, coil-to-coil, and phase-to-phase shorts and developing shorts, as well as cracked or broken rotor bars, uneven air gaps, and contamination.
Effective services and training
Electric motor and generator repair is more than just repairing a failure, suggests Matt Dreisilker, operations manager at Dreisilker Electric Motors. “It is understanding why the failure happened and preventing it from happening again,” he says. “Using Dreisilker's MotorSafe processes and highly skilled workforce, who work with the customer to understand their application and educate them, leads to increased uptime and reliable operations.”
Companies such as MotorDoc, an SMRP-approved training provider and new materials research company, provide industry training related to electric machine theory, materials, and testing, including time-to-failure estimation techniques and motor management.
“Electrical machinery has remained pretty much the same over the past 130 years with materials, appearance, and efficiency being the primary exceptions,” says Howard Penrose, president of MotorDoc. “There are changes in materials that improve electric machine life, such as improved materials, nanodielectric wire, and extruded insulation materials that will challenge how we test and evaluate the condition of machines in the future.”