EC Motor Start-up

Interesting information about EC motors that could lead to an incorrect diagnosis.

As of January 1, 2009, all walk-in manufacturing companies must sell their refrigeration units with Electronically Commutated (EC) motors. EC motors lower energy costs and significantly improve the walk-in cooler or freezer performance. These energy efficient motors are offered as a complete unit or as a drop-in replacement. Whichever your use is, if you are not familiar with the EC motor it may seem odd when you initially start it up.
When starting an EC motor, the motor must know where the rotor is located in order to start and continue to run. When power is first applied to the motor, the controller will apply a gradually increasing amount of current to all three windings in the motor over a period of 2 seconds. This will cause the rotor to move to a known location. This move will range from no movement at all if the rotor has stopped in the location needed for the next start or may be a much larger movement if it was a longer distance  from where it needed to be. With a fan blade attached, it may even overshoot and move backwards to get to the right location. After that 2 second “positioning” period the controller will start applying power to different phases in a slow rotating pattern that increases in speed over the next 2 seconds until the rotor is moving fast enough for the controller to be able to detect its location. This second phase of the start cycle usually happens so quickly that you cannot really see what is happening. Within 3 to 5 seconds of applying power, the motor should appear to be running normally, but during those first 2 seconds the movements may seem as though the unit is having troubles starting or is broken.

Energy Efficient Copeland Scroll Compressors for Walk-ins

Save valuable resources with energy efficient Copeland Scroll compressors, permanent split capacitor motors and electronically commutated evaporator motors on your next refrigeration system purchase. Scroll condensing units are available for medium and low temperature refrigeration applications. The condensing units are optimized to work with HFC refrigerant R-404A, a reliable alternative to HCFC R-22. As the energy efficiency trend increases, the use of scroll compressors is a more important feature than ever before. Scroll compressors are inherently more reliable because they have significantly fewer moving parts and handle liquid slugs and debris more effectively. The scroll technology has only three moving parts, as compared to the standard hermetic compressors that have 150 plus moving parts. Scroll is effective in using less energy or amp draws verses the standard hermetic compressor. Copeland studies indicate that up to a 15% reduction in energy use is experienced for most applications. When adding the benefit of PSC motors on condensers and EC motors for evaporators, energy use will decrease. Sizing refrigeration equipment to operate for 14 to 16 hours instead of the traditional 16 to 18 hour run time will also save energy by using less kilowatts and costing less to operate compressors and motors.

Copeland Scroll Refrigeration Compressor

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