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28 www.coalage.com November 2018 high-hp motors continued The high level of in-house quality control, and thus the high level of quality, helps differentiate MTI from its compet- itors, he said. "We feel like that is a huge advantage," he added. Quieter Reliable Efficiency Three high-hp motor offerings from ABB speak to coal mine site-specific require- ments and help miners attain some long- standing goals tied to safety, efficiency and sustainability, Leonard Eros, global mining manager, robotics and motion, ABB, reported in a white paper submitted to Coal Age. The company's induction motors, per- manent magnet motors and synchronous motors can be customized per site specs, and offer distinct benefits and advantages, ABB reported. Available in powers up to 25 megwatts (MW ), squirrel cage induction motors are usually the first considered. "Squirrel cage induction motors have been the workhors- es of the industry due to their versatility, reliability and simplicity," Eros report- ed. "ABB offers induction motors with increased protection ratings up to IP66, along with engineered dust shields and ro- bust fan covers to ensure low maintenance, improved reliability and an extended mo- tor lifetime." IP66 means that the enclosure is dust tight and will withstand powerful water jets, Eros reported. "High ingress protection marks a significant advance for high-voltage electric motors, as there have previously been few products on the market offering the IP66 rating in high-power motors." The resulting durability helps reduce production costs and increase sustainabil- ity, Eros reported. The company's N-series high-voltage induction motors are further described by the company as "reliable," cost and energy efficient and customizable, with short lead times. However, "it can be difficult to meet the new lower sounds level specifications with this design," Eros reported. "In these situations, our permanent magnet (PM) motors can be used as they often provide a reduced-noise solution." Connecting directly to the driven load and running at the final drive speed, PM motors run at lower speeds, producing less noise. "And if blowers are required for cooling they can be sound isolated more effectively than with shaft-mounted fans," Eros reported. "Eliminating the gear re- ducer also contributes to sound reduction, especially if the reducer required an exter- nal cooling system." The motors are "designed exclusively for frequency converter supply" and provide "high speed accuracy even without speed sensors because they are synchronous mo- tors without rotor slip," Eros reported. They offer 1,000 to 50,000 newton meters torque, feature enclosed IP 55 construction, and can be either air or liquid cooled. ABB's PM offerings also feature high efficiency ratings. "Typically, our PM mo- tors are rated at above 98% efficiency," Eros reported, "and when you factor in the normal 1.5%-4.5% loss in the gear reduc- ers, it's clear that gearless drive systems offer a significant improvement in overall system energy efficiency ratings." For more power and torque, ABB offers synchronous motors, noteworthy for their reported efficiency ratings. "Re- cent improvements in technology have made it possible for ABB to design and manufacture synchronous motors ex- ceeding 99% efficiency," Eros reported. "While this level is currently achievable in only very high-power machines, it is leading the way for efficiency improve- ments in all power ratings." The motors are designed for heavy-du- ty applications. "They operate at lower speeds than induction motors and can therefore drive the conveyor pulleys and other equipment directly, without the need for gearboxes and high-speed cou- plings," Eros reported. "The failure of just a single reducer component can cause a site's entire production to stop, so using synchronous motors without gearboxes increases reliability, availability and re- duces the production costs." All three lines of offerings were de- signed and developed based on customer feedback, enabling ABB to offer solutions that speak to exact site needs, Eros report- ed. "We use the goals our customers and partners share with us as guidelines in the design and manufacture of our high-pow- er mining motors." Drives of the Future FLANDERS' underground high-voltage variable frequency drives (VFD) for high- hp motors represent "the future of convey- or belt control underground," said Greg Hite, sales manager for the company. The drives enable precision belt con- trol and allow the mines to eliminate the use of power centers. "In that type of con- fined space, whenever you can take some- thing large like that out, you are making an improvement," Hite said. "It really speaks to the advancement in the technology in the underground industry." It also speaks to the bottom line by re- ducing belt maintenance, improving belt operability, and reducing the equipment involved in a conveyor belt system. "That power center is probably $300,000 sav- ings," Hite said. "That is a pretty substan- tial piece of equipment." The drives are air cooled and feature advanced controls and monitoring op- tions. "It has the onboarded technology with a PLC, so all the information is being communicated back to the operator and the control room," Hite said. ABB's permanent magnet motor solutions run at the speed of that which they drive, making them a viable solution for conveyors. (Photo: ABB) FLANDERS' high-voltage variable frequency drives is well-suited for longwall applica- tions and enables the miner to nix the use of a power center. (Photo: FLANDERS Inc.)