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How do I know if a electric motor is a good one?

Hi, I am trying to understand what makes an electric motor efficient. In particular, in small appliances. As I understand it, wattage is not necessarily a indicator of how good or bad a motor is. A 700 watt widget electric appliance may not mean anything. Indeed, a 700 watt may be bad because 700 watts is too high for a given type of appliance. That is the unit is working harder because it is not efficient and thus burning up 700 watts.

But how do I know if the electric motor a manufacturer is using is a good motor? Would I have to track down the manufacturer of the original motor the final manufacturer is using? For example, KitchenAid sells a 700 food processor at 1 HP. But how do I know the motor is a good motor?

I hope this makes sense.

Thank you for any help or links.

Reply to
needin4mation
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Dear needin4mation:

It doesn't matter in small appliances what the efficiency is. They don't run 24/7.

...

That is the $64 question. "Good" is not necessarily "efficient". Good is a motor that lasts as long as the mechanism it drives. I am aquainted with an application where a 10HP 500 rpm motor is lifting one end of a trailer full of fuzzy cotton seed. No additional bearings, the takeup reel is connected directly to the motor's output shaft. *That* is a good motor (and a bad application).

This will not be possible. I'd recommend:

- Consumer Reports, or

- buying an extended warranty for a time period no longer than you can usually keep records.

David A. Smith

Reply to
N:dlzc D:aol T:com (dlzc)

You have to know what your mechanical load is. There are 746 watts in a horsepower.

Don Kansas City

Reply to
Don A. Gilmore

One sure fire way to figure out if you have a good motor is to look at amp draw ratings stamped on it, or in the manufacturers specs. then using an amprobe determine the exact amp draw under the operating load. if its at or below that, your in good shape, over it, the motor is too small for the application

Reply to
thisoldfender

Electric motors produce a certain torque at a certain speed - it may well vary at different speeds. That's the desired mechanical power. And electric motors generate heat. That's the undesired output (unless it contributes to heating your house, which makes it an acceptable waste.) So input electrical power = output mechanical power plus waste heat. Motor efficiency is expressed as output mech power / input elec power X 100%

Brian Whatcott Altus OK

Reply to
Brian Whatcott

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