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Electronically Commuted Motors to Replace Inefficient Fan Motors
in Commercial Walk-in Coolers and Freezers
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Electronically Commutated Motor (ECM) FAQ
- What's so special about an electronically commutated motor (ECM)?
- An ECM is more expensive than a comparable shaded pole fan motor. Why pay the extra cost?
- What makes an ECM so efficient? How does it differ from a conventional motor?
- What about reliability? There are reports that ECMs are sensitive to water damage.
- Why not just wait until each shaded pole motor fails before replacing it with an ECM?
- If this new ECM is so impressive, why isn't it offered in new equipment?
- Does this motor work in any brand and model of evaporator? Does it work in freezers?
- What about replacing PSC motors?
- How can I tell if my evaporator fan motors are shaded pole or PSC?
- It looks as if most utility companies are not currently offering incentives for installing EC motors. Is this expected to change?
Downloads:
WEEC 2004 Paper on Evaporator Fan Motor Energy Conservation Retrofit (357k)
This paper was presented as a poster session at the 2004, Austin, TX World Energy Engineering Congress. It discusses the use of electronically commutated motors (ECM) as energy retrofit for evaporator fan motors in walk-in coolers and freezers. Included are application areas, pictures, return on investment (ROI) charts, installation considerations, life cycle costs and utility testing data.
84mm ECM at a Glance (88k)
Key features of GE's new 84mm electronically commutated motor are listed on one page, along with a break-even chart for retrofit of shaded pole motors with the ECM. A second page answers frequently asked questions.
84mm
ECM - Complete Literature Package (1.4 MB)
The literature package includes: a utility energy savings study, General Electric motor description and picture, motor efficiency maps, a scatter diagram of 46 shaded pole motor true RMS power measurements, rebates and incentives for this new motor and break-even charts that show a family of curves based on energy only, energy and refrigeration, and
energy, refrigeration and rebate all versus electric rates.
Break-Even Charts for ECM (48k)
The chart varies electric rate versus break-even based on a series of key assumptions. Shown is a straight electricity only break-even, then one that considers refrigeration (1.7KW/Ton efficiency), then a rebate of 8 cents/kWh (California Standard Performance contract) and finally improved maintenance is considered. Each of this aspects can be customized using the ROI calculator that can be downloaded below.
Technology
Paper: Electronically Commutated Systems for Fans (679k)
This four page paper by Armin Hauer of ebm Industries is an excellent overview of the core technological attributes of electronically commutated (EC) motor systems that are widely used as drives for equipment fans. The reliability and high efficiency (70%-95%) of EC motors has been proven for the last two decades. Included are efficiency charts for Shaded Pole, PSC, three phase induction and EC motors. Examples of typical applications are included.
GE
Product Warranty (263k)
GE Industrial Systems provides a standard limited one year warranty from the date of installation or eighteen months from the date of manufacture, whichever comes first. Of note is that water damage is included in the warranty, examples include condensation or heat-exchanger blow-off. If the motor is damaged by water, other than natural disaster, flood, etc., the motor will be repaired or replaced at GE's option after it is returned to the factory.
Motor Retrofits in Grocery Walk-in Coolers (1 MB)
This presentation illustrates the problem of inefficient shaded pole fan motors found in many walk-in coolers and freezers, and the energy-saving solution offered by GE's 84mm electronically commutated motor. Included: shaded-pole motor density in typical grocery stores; before-and-after motor retrofit tests; benefits of an in-store survey; elements of the ROI calculation; typical issues encountered during the retrofit process.
AC Energy Equations (28k)
Equations for determining air conditioning and refrigeration savings resulting from lighting or other electrical load reductions. For example, the equations answer the question - How much additional air conditioning energy savings will there be from a heat load reduction in a walk-in cooler by a kilowatt? The equation supports varying air conditioning efficiencies.
84mm
ECM ROI Calculator (MS Excel file)
This MS Excel file allows complete customization of the ROI model. Specific electric rates, power figures, motor and store densities, rebates, and maintenance figures all can be input. Coupled with a detailed survey of several stores, this calculator can provide a very sharp estimate of the actual energy savings that is possible by retrofitting existing shaded pole evaporator fan motors with new electronically commutated motors.
