New blower motor running slowly


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Old 06-21-08, 03:45 PM
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New blower motor running slowly

I just replaced my old GE blower motor that finally burned out (specs= Direct Drive, Permanent split capacitor, 115 Volts, Single Phase, 1075 RPM, 4 Speed, 3.40 amps, 1/5 HP, 60 HZ, capacitor 7.5 MFD - 370V) with a new AO Smith motor.

All specs are the same on the AO Smith except for 3.2 amps (vs. 3.4 on old) and 3 Speed (vs. 4spd on old, but not that big of a deal, since old motor only had power running to High and Low motor leads anyway).

Ran all wiring as indicated in diagram and motor runs, just at approx. 50% the speed of old motor. Tried switching leads and motor ran even slower which made sense because power was now going to the Medium and Low leads.

I did not replace the capacitor (but probably should have and will if instructed to now), but new motor does not lag at start so I'm not completely sold that the capacitor is the problem.
 
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Old 06-21-08, 09:41 PM
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Better go back and recheck that replacement motor, sounds like it is a 220 volt model.
 
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Old 06-21-08, 09:53 PM
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Motor is 115 V

Just quadruple checked... its 115V. Also changed the run capacitor today... no change.

The motor is AO Smith BL6505V1. Is it possible to connect two of the motor leads (High and Med) to speed up the motor? Obviously grasping at straws, but it has been crazy hot today and I think my brain is fried from working on the a/c in the attic.
 
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Old 06-22-08, 09:44 AM
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Must be wired incorrectly, explain what you have hooked up now especially to the capacitor. And then type in the wiring instructions for the motor and we can sort it out in a few minutes
 
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Old 06-22-08, 10:34 AM
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Multi HP motor, 1/5, 1/8, 1/10. Also reversable. Is the fan turning the right way?

Look at the fan, blades look sort of like cups. Fan should turn so the "cups" scoop the air and throw it out the discharge.

If running backwards, it has no work to do and is operating at 1/10 hp.

Also never cahnge anything that has a capacitor without also changing the capacitor.
 
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Old 06-22-08, 05:28 PM
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Thumbs up Thank you BIG TIME Jarredsdad

That fixed it!

Motor was running CCW and I needed it to run CW, or at least what I thought was was CW. The old motor was not reversible and showed an arrow for its rotation on the faceplate. It looked like CW to me, so that's what I followed on the schematic for the new motor. ERRRR... wrong... try again. I had checked my wiring job so many times against the diagram that I was almost offended by the assertion it could be running the wrong way.

Pretty glad I went back up there one more time to look (and really glad I didn't have to pay $400 + to have someone come out to do what I was able to do for about $100). It also scored me major points with "SHE WHO MUST BE OBEYED"

Thanks for helping me see something that was right in front of my face!!
 
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Old 06-23-08, 02:11 PM
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Don't be too hard on yourself.

I'm not afraid or ashamed to admit that every once and a while I find that I need to step back from the mountain I'm working and take a better look at the mole hill I came to fix.
 
 

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