||08-10-2011 02:20 AM
Wiring a replacement blower motor
I previously had an A.O. Smith 4 speed motor 1050 hp 115v. (part# 321p591) for the blower on my furnace. The wife noticed a bad smell and it stopped running. You can hear the electricity hum when it turns on, but it doesn't spin. The motor is also hot to the touch. I believe the bearings went bad on it. So I bought a replacement motor: GE, PSC, 1/3 HP, 1075 RPM, 115V, OPAO, 48YZ 2 speed.
The wires for the old motor looked like this: https://lh4.googleusercontent.com/-w...2/IMAG0031.jpg
The setup in the furnace looked like this: (Furnace wires to the left, motor wires to the right)
The new motor has two capacitor wires (brown and brown/white), a white wire, Black wire (labeled as Hi (speed?)) and red wire (labeled as lo (speed?))
The old motor was not wired to a capacitor. I checked everywhere and could not find one. I assume that the old white wire labeled C was a capacitor wire, possibly built into the motor. I wired the brown, brown/white and white wires to the furnace white wire, the black to black and red to red. When I turn it on, I can hear the electric hum, but the blower is not spinning. Do I need a capacitor with this new motor? I'm a little frustrated that the technician at the parts store where I got the motor didn't tell me I need a capacitor with the new motor. I'm also questioning whether the replacement motor I got is a good replacement one for the old A.O Smith one, since the new motor is only a 2 speed instead of 4 speed. Any thoughts on this?
I've also noticed a green spark coming from the safety switch on the furnace when I push it in and it turns on or when I let go of it and it turns off. Is this normal?