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Motor Identification 1

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Colt1911

Computer
Sep 29, 2010
10
Need help in determining what type of motor I have. I have an idea, but want some input from someone more learned than myself. The reason I need to know is because I intend to attach a motor speed control, and some of the information I have is in conflict.

The facts:

The product is Master Flow PG1 Gable Vent (it is not the newer models nor does it use the newer replacement motor listed on their website)

Label information:
DM (Asia) limited
model#:DOW-136-0-34-XIN
UL (listing#) E193815
1050RPM

6 poles are clearly visible from the back of the motor, so I'm guessing brushless AC induction.

My conflicting information is:

1 HP=746w (%100 efficiency)
The label states 3.4 amp. I tested the motor at 3.4 amp.
My math: (V=IE) 120*3.4=408w
746/408=1.8HP

The label states 1/13HP ?!?! (misprint?? 1/3??)

Question:

1. Is there a definitatve way to determine the type of motor? (ie brushless/brushed) (AC/DC)

2. Where have I gone wrong in my calculation of the power/HP of the motor

3. What type of speed controller will I need? (frequency/pwm/rheostat?)

4. If I need to build a circuit for cost effectiveness, any good links to what I might need?

Thanks
Colt
 
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By the way, homeowner DIY posting is verbotten here, hope you read this before it gets deleted.
 
@jraef

Thanks for the more verbose explantion of the consumption vs. output rating. That was one of the things that puzzled me a bit. It seemed strange that 3.4A @ 120V would have such a low HP output.

The complexity of the controller is of no concern to me, I have built more than a few MP controlled circuits. Unfortunately the base efficiency will preclude this motor from being in service for this project.

Thanks for the link. Dont know if I will need it until I get a new fan and/or motor.

Actually had to look up 'verbotten' LOL :) No worries I am a licensed and insured contractor. I do general remodeling to make a living. In addition I have a degree in electronics, and auto mechanics. Furthermore; the 'project' is a photo studio for my wife which has a building permit on file. So I think a 'homeowner DIY' is a bit of a stretch in this case.

What the fan is being used for is plenum ventilation. We built a second story on our house, the HVAC is in our first floor attic, so we installed floor vents for the second floor, so there is no ventilation ducts in the second floor celing. There is to be recessed HID lighting in the celing (plenum) and since it is a 10' celing, remote ballast is out of the question. HID lights and their ballast get very, very hot, so the plan is to vent the plenum. I got the gable vent but its loud. Being that it moves 1250 CFM, I thought if I slowed it down would cut out the noise. Little did I know in this century an electric motor would be so inefficient. The fan has to run all the time the lights are on.

So I may use the shaft and add a pully with a belt drive and a more efficient motor, or get another unit altogether. I hate to buy and install an entire air handler unit, but might have to in the end. I will do my homework on electic motors this time before I buy something, or I may go with a squirrl cage type blower. Its 'back to the drawing board' :p

Colt
 
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