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  1. #1
    Join Date
    May 2010
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    New jeresey
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    15

    Thumbs up low motor amperage

    On my main air handler, will the fan motor draw less amps if the return damper shuts. Or will the amperage go up due to the motor working harder trying to pull back air causing amps to go up.

  2. #2
    Join Date
    Mar 2003
    Posts
    7,326
    depends upon the fan type, but most likely it will go down from moving less air.

  3. #3
    Join Date
    May 2010
    Location
    New jeresey
    Posts
    15
    Quote Originally Posted by flange View Post
    depends upon the fan type, but most likely it will go down from moving less air.
    Ya thats what im thinking thanks.

  4. #4
    Join Date
    Mar 2010
    Location
    Morgan Hill Ca.
    Posts
    1,230
    Quote Originally Posted by icedr024 View Post
    On my main air handler, will the fan motor draw less amps if the return damper shuts. Or will the amperage go up due to the motor working harder trying to pull back air causing amps to go up.
    If this is a squirrel cage or backward incline, the amps will drop, but only because you are moving less air...

    Think of what happens to a vacuum cleaner if you plug the suction hose with your hand....Does the motor speed up, or slow down? It speeds up because you have removed a major portion if the load from the impeller..

    On a propeller fan, typically the fan will slow down, propeller fans are great for moving mass quantities of air, but can't build much static...

    GT
    If a day goes by and you have learned nothing, I hope you got a lot of sleep.

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