A/C blower motor for fireplace dead?

[gabeNC]

Blower motor started squealing so thought maybe I should replace the bearings. Drilled out the old rivets and much to my surprise it was only a sleeve. Quick trip the local bearing store and found the perfect match. Now after reassembly the motor acts like a electro magnet, nice humming sound and the rotor is seized. I quickly turn off the power and the rotor can freely spin.

I don't think it was put back together incorrectly as the motor can only be assembled one way. I also expected a coil to be open but a quick check with the ohm meter gives decent readings. Thought maybe I could save $140 but maybe not. Any ideas?

thanks.


**broken link removed**

 

[KeepItSimpleStupid]

I'm not sure of what kind of motor it is. A shot of the nameplate would have been nice. Is it a PSC motor? Capacitor start motor or capacitor start/capacitor run motor?

A PSC motor and a cap start/cap run needs the cap to run. If the cap is bad or not connected on some type of motors, you can get ittorun if you spin the shaft in any direction.

Take a pic of the name plate and see if we can go from there. You can try the spin trick and see what happens.

 

[ben7]

Perhaps some of the wires are backwards.

 

[cowana]

Or prehaps there is a little play in the new bearings, and when power is applied it is touching at one side?

 

[HiTech]

From what I can tell, it looks like that bearing is a "wobble" type. It's can be forced out of center if need be. That makes it VERY IMPORTANT to have it exactly square/true to the armature shaft or it will bind on the shaft or cause armature rubbing. Spend time carefully realigning the entire assembly.

 

[gabeNC]

Thanks gents. The old bushing is in the picture sitting by itself. Under the silver "cap" there is a spring that holds down the bushing and allows the rotor to "float" or have a little give if necessary ( i guess), seemed to hold the bearing in place nicely too.

The rotor spins freely with no power applied, does not rub against the stator. I don't see a start-up cap. I also took out the other blower motor and compared to make sure I was putting it back together correctly and seems ok.

 

[#12]

I've done dozens of these over the years, and never failed. They are that simple. I was going to tell you to beat it softly about the head and shoulders before tightening the screws, but if it spins by hand, you did that part right. I'm afraid you broke a wire.

 

[HiTech]

..... I was going to tell you to beat it softly about the head and shoulders ....

Now there's an oxymoron statement -- "beat it softly"

You didn't happen to attend a parochial grade school during your youth, did you? I did, and the nuns would beat us softly on the head or shoulder with a ruler until we knew the material forward and backward!

 

[D Dusentrieb]

I see that your motor has 3 wires. Does it have a starter capacitor? Check/replace that one. It is the weakest part in the system!
D Dusentrieb

 

[Doktor Jones]

If your motor does seem to be dead, I've learned from my experience working at a surplus electronics store that people love to replace the entire blower with a simple DC fan... find a 12, 24V, or 48V DC fan and a good switching power supply to match, and you'll have yourself a replacement for $20-30. Of course, I don't know how yours is mounted or what type it is (squirrel cage, muffin fan, etc) and how willing you are to adapt another type/size of fan to fit, but customers at our store seemed happy enough with the results

 

[260z]

In the picture it looks like rub mark on the rotor. The extra wires are probably for the two speed feature. If you try it in the other speed and it goes then that speed winding is dead. Sometimes when putting it back together you can get it mialigned so that it spins free with no power but jams when power is applied. If you try the spin it when it hums trick and it wont turn that is probably whats wrong. Hope this helps.