Appliance Design - January 2008 - (Page 30)

MOTORS Direct Electricity Savings (30-in. fan). 2000 between 6 months and 3 years. 1800 50% flow = 16% input wattage At the state level, the most pressing regulatory action is occurring in California and it mandates 1600 that commercial refrigeration appliances use EC 1400 motors. “Regulatory pressures have been mak1200 ing product adaptability a key issue lately,” says 1000 Tim Neal, Industry Leader for Commercial 800 Refrigeration at GE ECM by Regal Beloit, Beloit, Wis. “Starting January 1, California’s Title 20 600 appliance efficiency standards will require that External Rotor Async Motor with Triac 400 External Rotor Async Motor with Transformer all new walk-in coolers and commercial freezExternal Rotor Async Motor with Inverter (=VFD) 200 ers use ECM evaporator fans. With many states EC unit A3G800 using linear / PWM Input 0 referring to Title 20 in their own efficiency rul5000 7000 9000 11000 13000 15000 17000 19000 ings, this new standard will quickly become the Air Performance [m³/h] Source: ebm-papst law of the land.” Michael Jenkins, sales manager for North American operations for Elco Motors of Quebec, Canada, says that electronically commutated motors, which use brushless-DC technology, are inherently more efficient than traditional AC asynchronous induction motors, in practically any load condition. The higher efficiency mainly is the result of the use of permanent magnets to generate the rotor magnet field. “This solution sensibly reduces magnetic and Joule-effect energy losses against the traditional squirrel-cage rotor,” he says. The benefit of improved efficiency is driving many manufacturers toward using electronically commutated motors, says Jenkins, especially on evaporator applications such as display cases for supermarkets, convenience stores and appliances, and especially with remote condensing units, he says. “With these types of products, energy efficiency will payback the additional cost of the motor in such a rapid fashion that most of the new applications are going into energy efficient ECM motors.” Commercial refrigeration encompasses a wide-ranging product mix that includes everything from large walk-in freezers, to small, refrigerated-display cases, and icecream machines to ice-making machines. The MCE-IP65 EC motor from Elco Motors can drive 6 to 10 in. fans and feature efficiencies of up to 70 percent. While as a group these products are lumped together, the particular application will affect the designer’s specification of motors. “This is first of all based on required airflow,” says Armin Hauer, product manager for ebmpapst of Farmington, Conn. “The larger a fan of a given geometry and airflow, the higher the motor torque requirement. Motor torque generally determines the motor frame size.” According to Hauer, refrigerated vending machines traditionally use 1,550-RPM motors with an output of about 12 W. Refrigerated display cases are usually designed for 7 in. to 11 in. Source: Food Service Technology Center 30 applianceDESIGN January 2008 Input Power [Watts] www.applianceDESIGN.com http://www.appliancedesign.com

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Appliance Design - January 2008 Contents Editorial Shipments/Forecasts News Watch Makers of Commercial Refrigeration Equipment Turn to Variable-Speed Motors to Improve Energy Efficiency. New Motor Design and Control Scheme Makes Brushless Motors More Economically Feasible for a Wider Range of Applications. External Gas Molding, a Relatively New Technique, Solves Many of the Challenges Associated with the Injection Molding of Large Plastic Parts. Plastic Housings Offer Many Benefits: EMI Protection Isn't One of Them. But, New Materials and Techniques are Solving that Problem. Choosing the Optimal Strategy for Effective EMI Shielding Depends on Both Mechanical and Electrical Requirements Ethernet-Enabled Microcontroller Makes Networking Schemes Easier and More Cost Effective to Implement The Ever-Changing Array of Microcontroller Memory Options Makes it Imperative to Keep Abreast of What's Available to Determine the Optimal Choice for an Application. A Vast Range of Components and Finished Products will be Exhibited at the Country's Preeminent HVAC/R Show, AHR Expo, which is Scheduled for Jan. 22-24 in New York. Advertiser's Index Association Report: PRBA

Appliance Design - January 2008

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