Replace old furnace blower motor with a new one but the wires are different

hvac

enter image description hereIt is an old Rheem RGAA-100C furnace, On the old motor the wires was: White, Brown, Red, Black and Blue. On the new Motor it has Brown, Brown/White, Black, Red, White, and Blue. I don't know how to wire it back. They do not make the old motor anymore, this motor was the replacement. Could you please help.

On the circuit diagram on the motor says:

  • Br/Wh to Cap.
  • Br to Cap.
  • Wh to Line.
  • [Blk (Hi) or Blue (Med) or Red (Low)] to Line.

Best Answer

There should be a schematic printed on a sticker on the motor. Without knowing the make and model, or looking at the diagram. I'm guessing based on other motors.

One common "standard" is as follows:

  • White = grounded (neutral) (clockwise).
  • Black = High speed.
  • Blue = Medium speed (medium low).
  • Red = Low speed.
  • Brown = Run capacitor.
  • Brown w/ white = Run capacitor.
  • Green = Ground.
  • Yellow = Medium speed.
  • Purple = Grounded (neutral) (anticlockwise).

Optional wiring available on some motors.

However, without the make and model, or the schematic, this is just a guess.


Update

The two brown wires (Br and Br/Wh) should be connected to the capacitor. If you don't have one, you may need to install one. The brown wire from the old motor should have been connected to it, so try to remember where you removed the brown wire from.

The white wire from the motor, should connect to the white wire in the junction box. This is L2/neutral, and completes the circuit.

The remaining wires are for selecting the motor speed (Blk, Blue, Red), so you're going to have to figure out which speed you should be using. If you can remember which color wire was connected to the red wire in the junction box, that should be the same color wire to hook back up. Typically the blower is run at low speed when in heating mode, but that's no guarantee that your equipment was set up that way.

I wasn't able to locate any documentation on your equipment, and without a schematic I can't be any more specific. If you could include a good photo of the schematic, I could show you where to make the connections. You should be able to find a schematic in the manufacturer's documentation, or on the furnaces access panel.