Dayton blower motor

[artieb]

Hi, I have a furnace blower that I want to use, and it hums and if I start to spin it will go in the direction I spin. I have a pic of the spec. sticker and says nothing about a capacitor to start. Is it junk, or do I need a cap to start?

 

[gungatim]

hmmm...looks just like the one I used to power a meat grinder. came off a furnace as well. No cap on mine and it starts immediately. it's just wired through a light switch and plug. may be junk...

pics attached...not a Dayton but about the same I think.

 

[MFolks]

http://www.ask.com/youtube?q=furnace+blower+motor+wiring&v=oyppEsC7n5s&qsrc=472

 

[G_P]

Could be a bad start winding. IIRC those still use a centrifugal switch that cuts out the start winding when the motor gets up to speed. Either the winding has a broken wire and is not working, or the centrifugal switch may be dirty or stuck open not allowing the winding to start the motor properly.
Try swapping the red and black wires and then see if it starts.

 

[artieb]

Thanks G_P, this makes total sense. Is the centrifugal switch a physical switch with a spring on a arm, with a contact? Just pull the end cover bearing plate, and clean? I have another split-phase motor, I put on the blower, and that motor appears to have this switch stuck closed. Starts, runs, gets hot, then thermo overloads off. Pulls 5 amps continually. Thanks Artie

 

[LS6 Tommy]

It's a split phase motor. It does not use a run cap. Either the centrifugal switch is stuck open, bad or the start winding is bad.

Tommy

 

[nehog]

I... Either the centrifugal switch is stuck open...

My money is on this--check and clean the start switch.

 

[G_P]

The centrifugal switch is a C shaped brass spring that rides on a plastic disc on the motor shaft. The plastic disc is pushed outwards by weights and retracts when the motor slows to a stop. If the weights are stuck, or the switch contact is dirty, the switch may never close and therefore would not start.