MRO Magazine


STUDY SHOWS ELECTRIC MOTORS CAN BE REWOUND WITHOUT REDUCING EFFICIENCYThe results of a new study on the impact of rewinding on the energy efficiency of electric motors have been released by the Electr...

November 1, 2002 | By MRO Magazine


The results of a new study on the impact of rewinding on the energy efficiency of electric motors have been released by the Electrical Apparatus Service Association (EASA). The study concludes that using best repair/rewind practices maintains a motor’s energy efficiency.

Typically, over 97 per cent of the lifetime cost of an electric motor is the electricity it uses to operate. Even small changes in a motor’s efficiency can have a large effect on operating costs. There is a common misconception that rewinding a motor will degrade its efficiency, a misconception that may influence the user’s decision in determining whether to repair or replace a failed motor. Based on the results of the study, it is clear that electric motors can be rewound/repaired multiple times with no change to operating costs.

This comprehensive study was launched in 2000 under the leadership of EASA and the Association of Electrical and Mechanical Trades of the United Kingdom. Other project sponsors included the U.S. Department of Energy and the U.K.’s Energy Efficient Best Practice Program.


Ten of the world’s largest electric motor manufacturers provided motors, technical data and assistance. The motors examined were 50 hp to 300 hp electric motors and included low and medium voltages, IEC and NEMA designs, totally enclosed and open drip-proof, and 1,800 rpm and 3,600 rpm ratings.

A white paper, “The Results are In: Motor Repair’s Impact on Efficiency,” can be viewed at


Siemens Canada of Mississauga, Ont., has won a contract to supply automation technology for a new vapour recovery system operated by Canadian Natural Resources Limited (CNRL). It is to be used at a heavy oil production site in northeastern Alberta known as Primrose. The contract is valued at $1.8 million.

CNRL has developed the new technology in response to a requirement of the Alberta Energy and Utilities Board. Under new regulations, the province’s oil and gas producers must recover, rather than burn off, excess gases that are contained in extracted oil and gas.

CNRL’s technological response to the new requirement matches advanced multi-phase pumping technology with energy efficient automation technology from Siemens.

To meet the no emission goal, CNRL’s engineers selected a system in which multi-phase pumps, supplied by Borneman Pumps of Germany, act as separation devices able to handle all of the liquids and gases that emerge from a producing well. This is combined with advanced automation devices to control the variable speeds at which the pumps operate, including motors, motor drives and programmable logic controllers (PLCs).

A complete system is assembled on a skid that is easily placed at a production site. Each skid will handle the needs of up to 20 pump jacks.

After successfully beta testing the Siemens technology, CNRL was able to downgrade its motor specification from 500 hp to 300 hp. This resulted in substantial equipment and energy cost savings without jeopardizing production efficiencies.

Siemens also demonstrated that an approach that integrated its technology could reduce capital and operating costs given that its motors and drives could perform at efficiencies above industry norms.

The Siemens proposal was centred on the use of a Profibus communications network and the ability to integrate its devices without the additional cost of interface devices that would be required if equipment from various automation suppliers was selected.


Ontario’s GDP per person is almost 14 per cent lower than the median of 16 comparable North American jurisdictions. This performance gap equates to nearly $6,000 for every person in Ontario. This was a conclusion of the second working paper released in September by the Institute for Competitiveness & Prosperity in Toronto.

The working paper demonstrates that while Ontario’s economy performs extremely well globally, it trails many of the U.S. states in its peer group.

“Ontario’s economy is one of the strongest in the world,” said Roger Martin, dean of the University of Toronto’s Rotman School of Management and chairman of the Institute for Competitiveness and Prosperity. “But when we compare it to a peer group of U.S. states and Quebec, we rank 14th out of 16.

The working paper identified productivity as the primary source of Ontario’s performance gap. Martin said, “Improving productivity isn’t getting us to work harder — in fact a more productive economy provides more leisure time, if that’s how people choose to benefit from it.

“Productivity comes from innovation and upgrading our products and processes and we believe this is a function of our attitudes, investments and motivations.”

The complete paper can be downloaded directly from:


A huge, 48-ft high “Hammering Man” hollow-fabricated steel sculpture in front of the art museum in Seattle, Wash., hammers away continuously at a piece of metal, its giant mechanical arm controlled by a 3-hp motor and a Cone Drive double enveloping worm gearbox.

Designed to represent the worker, the figure hammers four times per minute 15 hours per day, with just one day’s respite per year on Labour Day; and it has been doing this for the past 11 years — over 12 million hammer strokes — without any problems with the gearbox.

Jim Virmala from Cone Drive, who dealt with the original installation in 1991, explains, “The designers wanted a gearbox that would operate in a quiet and smooth manner but would be rugged and durable as well.

“A double enveloping design, where the worm and gear wrap around each other, was a clear favourite due to its high torque capacity and ability to handle heavy loads.” A gearbox with a ratio of 450:1 was provided with special breathers to cope with the outdoor environment.


The separation of compound materials used in the machine, electronic and packaging industries into basic materials through chemical or thermal processes is costly and damaging to the environment. A promising materials recovery process has been introduced to North America by Swiss-based Result Technology, a long-time specialist in the disintegration and separation of compound materials through an environmentally friendly mechanical process.

Says Peter Virsik, vice-president of sales and marketing at the company, “The economic aspects of this new technology are dramatic, with a high recovery rate of valuable substances now possible. This recovery process has no damaging environmental impact, since it uses no fluids, gases or chemicals that would accumulate toxic substances or hazardous wastes. And the applications are wide for a diversity of industries that want to divert their waste products from costly landfills and incinerators.”

The process can recover a wide range of materials. It can salvage rubber and textiles from tires. The growing problem of electronic wastes such as printed computer circuits in landfills is alleviated by the process’s recovery of materials ranging from copper, aluminum, lead and tin to more precious gold, silver and platinum. Large quantities of plastics and metals can be recovered using the process, which delaminates or separates compound materials that are fused or laminated together, and which currently are sent to landfills or incinerated. Also, electric cabling can be transformed into once-again usable aluminum, copper and plastic.

Result Technology expects to sell the equipment for this process to recycling companies, original equipment manufacturers and other businesses throughout North America, in addition to commissioning complete turnkey plants which use the proprietary recovery process.

More information ab
out the company and the applications of its recovery process can be found at the company’s website,


The Vancouver, B.C., companies DynaMotive Technologies Corp. and Canfor Ltd. plan to develop commercial applications for BioOil, a clean burning fuel derived from such things as bark, sawdust and sugar cane bagasse.

The process uses a fast pyrolysis technology called BioTherm which converts biomass to liquid fuel (BioOil). “This technology also has the potential to provide Canfor with positive environmental benefits by helping to eliminate beehive burners currently being used to incarcerate the material,” said David Emerson, president and CEO of Canfor.

As well, Emerson said that BioOil might serve as an alternative to natural gas to fuel its pulp mill limekilns and sawmill dry kilns.

Canada’s forest industry produces about 18 million tonnes of sawmill residue a year, of which about 6 million tonnes is incinerated or landfilled at a cost to industry. Converting it to fuel contributes to reducing greenhouse gas emissions (GHG).

A 10-tonne-per-day pilot plant is operating in Vancouver, reports Andrew Kingston, president and CEO of DynaMotive. The partnership is looking at the commercial feasibility of developing a demonstration plant, which would produce between 25 and 50 tonnes per day of BioOil.


The Hydraulic Institute (HI) has endorsed the Premium Efficiency Electric Motor program, NEMA Premium, a designation that is given to electric motors that meet an industry-defined standard for premium efficiency. NEMA Premium was established by the National Electrical Manufacturers Association (NEMA), whose members make over 80 per cent of the electric motors sold in the United States.

This premium-efficiency program will boost energy conservation. As Robert Asdal, executive director of HI, says, “Because pumps are used in virtually every industrial and commercial enterprise, the energy savings potential, particularly in cases where the pump is being run in process-type operations, is very significant. This approach also applies to the motors that drive those pumps.”

According to NEMA, over 1.2 million integral horsepower electric motors are sold each year. Also, over 80 per cent of industrial, commercial and municipal pumps sold in North America are manufactured by HI members.

Research by the U.S. Department of Energy (DOE) has found that pumping systems account for nearly 20 per cent of the world’s electrical energy demand. Based on DOE data, it is estimated that the NEMA Premium efficiency motor program could save over 5,800 gigawatt hours of electricity and prevent the release of nearly 80 million metric tons of carbon dioxide into the atmosphere over the next 10 years. That would be the equivalent of keeping 16 million cars off the road.

The 85-year-old Hydraulic Institute serves member companies and pump users by providing product standards and forums for the exchange of industry information, including pump standards, life cycle cost guidelines, pump education and other resources. Nearly 100 pump producers and leading suppliers to the industry are HI members.

The organization is headquartered in Parsippany, N.J., with full information available at A new section of the web site, under “pumps and energy,” addresses the benefits of the NEMA Premium program and provides additional links for the benefit of users, specifying organizations and pump manufacturers.

NEMA is a trade association representing the interests of electro-industry manufacturers. Founded in 1926, its 400 member companies manufacture products used in the generation, transmission and distribution, control and end-use of electricity.


Danaher Corporation, a multinational manufacturing conglomerate based in Washington, D.C., has acquired Thomson Industries Inc. of Port Washington, N.Y. Thomson is a producer of linear bearings, ball screws, bearing balls and related products.

Danaher’s Motion Control Division, based in Amherst, N.Y., will absorb Thomson Industries. Motion Control and its Linear Motion Systems business group produce linear motion products under such names as Kollmorgen, Deltran, Warner Linear, and Ball Screws and Actuators.

Thomson Industries was founded in 1945 by John B. Thomson, Sr. Mr. Thomson invented the ball bushing linear bearing and developed the necessary manufacturing processes.

Danaher also has entered into an agreement to purchase Raytek for approximately US$75 million. With 2001 revenues exceeding $50 million, Raytek will be part of Danaher’s electronic test and measurement arm.


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