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Belt driven to direct drive conversion kit

zepfan Member Posts: 398
Does anyone know of a belt driven to direct drive conversion kit? The situation is that we have a building with about 70 Trane belt driven fan coil units, ceiling mounted. The units are almost 20 years old and some of the bearings on the units are starting to wear out. The issue is the three legged brackets that support the bearings, are no longer made by Trane. In the past we have changed the support brackets at the same time we have changed the bearings. Furthermore it would eliminate a lot of material and maintenance if these units were direct drive. Currently Trane does not offer a conversion kit. i have thought about making our own, with a Fasco motor band but the sticking point is getting something that will join the 1/2" shaft of the 1/3 HP direct drive motor, to the 3/4" blower hub. Any suggestions, or ideas would be much appreciated. thanks to all


    EBEBRATT-Ed Member Posts: 15,629
    You got some options:

    But first you have to consider how are you going to keep the fans running at the same RPM they are now running?

    Changing the fan speed could have a lot of implications like

    1 The new DD motor with the same horsepower may not be able to drive the fan at the speed of the new motor without overloading.

    2 If it's air conditioning increased fan speed may pull water off the coil.


    It would be a simple matter to buy bushings to put a 1/2" shaft into the 3/4" blower wheel. If you can't buy them it would be an easy trick to have a machine shop make them.

    Or have a machine shop make new 3 leg brackets

    Or mount an angle iron to the blower housing and use pillow block type bearings. You could pull the whole blower out and nut and bolt an angle iron to the blower housing to support the pillow block bearing.

    depending on the blower wheel size I would be cautious about a 1/2" fan motor holding up on a large blower

    Have a sheet metal shop make you the 3-leg brackets and keep them direct drive
  • mattmia2
    mattmia2 Member Posts: 9,749
    an you replace the bearing in the bracket? You can probably get it from whoever trane did if it un-clamps or presses out of the bracket.

    Could you replace the whole blower with a direct drive blower?
  • zepfan
    zepfan Member Posts: 398
    thanks for all that responded. I am leaning to taking the bearing support bracket to a metal shop and having the fabricate some for us. thanks to all