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Testing blower motors

on two-stage outfit. One blower speed stayed hot all the time while other one came on as well. So; can you check resistance thru windings to see if they are in spec?


  • Plumdog_2
    Plumdog_2 Member Posts: 873
    Testing Blower Motors

    What's proper way to test shaded pole 1/3 hp 3 or 4 speed blower motors to determine suitability for continued use? I have amprobe, digital voltmeter, etc. Had one wired hot to two speeds at once and draws big amperage now. Smells like electic toast.
    CHARLES_4 Member Posts: 61

    Well, I guess you won't do that again. Replace the motor--you've compromised the windings. Not today, maybe not even tomorrow. No, that motor will die when it's the least convenient time for you and/or your customer. And remember--experience is what you have right after you needed it.
  • don_163
    don_163 Member Posts: 67
    I agree

    with charles them motor dont smell nor taste good when you have to eat them.

    But hey remember you can only eat two.LOL.

    I had fan relays that would not open the normally closed contact on fan relays and burn out a newly install motor.

    Just when you assume Mr murphy is always there to greet you.

    Welcome to the club.

  • Eugene Silberstein
    Eugene Silberstein Member Posts: 1,380
    Sounds like...

    Sounds like you partially shorted a winding...

    Shorted winding = reduced resistance = increased amperage = more heat generated = more damaged windings = more severe short circuit = higher amperage = a bad thing

    The moral of the story is... Never energize more than one motor speed at a time!
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