Page 4 of 5
Re: AO Smith motor rebuild
Posted: Wed Oct 14, 2015 11:37 pm
by JPG
richardrouse wrote:Thanks again for all the input guys! The clicking that I'm hearing is the armature of the start switch rising and falling against the black plate. Once the motor stars, the clicking stops. I assumed that the lack of click was when the centrifical switch had pulled away from the contacts of the starter switch.
Bear with me here guys I'm thinking through the problem in light of what I've read.
So, I can hear the clicking when I turn the rotor by hand and when it coasts to a stop .. Otherwise when its running I just get motor noise.
Unless I'm completely misunderstanding how the motor works,
While at rest the centrifical switch relaxes and allows the black rub plate to pass over the contacts of the starter. This closes the circuit on the starter windings for start . once the motor gets a run command, the rotor spins and at some speed the weights in the centrifical switch pulls the rub plate away from the starter and remove it from the circuit.
So, because when I turn the rotor by hand, I can hear the armature moving up and down.. That means that the starter is taken out of the circuit every fraction of a turn. ( that would be why I have to turn it by hand occasionally... To line the rub plate back up with the contacts of the starter).
Am I on the right path? If not slap me and reel me back in.
I'll have to snap a picture of it tomorrow to show you all what is there.
I'll get some video as well.
Question:
1) I should not hear any clicking when the motor is at rest because the rub plate should be in constant contact with the starter while the motor is at rest? CORRECT
2) as far as checking the starter itself, I have placed my meter's probes across the solder joint and the lead that goes to the run switch.. I have continuity across those leads when the armature of the starter is closed.. Is there a way to check the windings? I've checked for ground faults on all of the leads and didn't have any.
Is there a better way to check the switch?NOPE
If there were a 'problem' with the start windings, you would not have had the earlier symptoms.
When rotating by hand, the contacts should remain closed. Determine the source of that click and make it go away! The normal click should become apparent once at startup, and once at slow down.
Yer gaining on it!!!
Now for 'nomenclature'.
There is no 'starter'.
There are start windings(but only two leads).
There is a start switch.
There is a start switch actuator(centrifugally weighted mechanism).
The start circuit(start switch, capacitor, start windings, electrical source fed through power switch) is only active at initial startup.
Re: AO Smith motor rebuild
Posted: Thu Oct 15, 2015 6:52 am
by richardrouse
I see now! Thank you sensei!
Sorry about the nomenclature. I know its maddening to try to help someone that doesn't know what the heck they are talking about.
I know why the switch actuator is riding too high, I took out a little spacer thingy that was in the front end cap out because I thought I was supposed to hear the armature on the switch moving. I, now, understand why that line of thought was totaly wrong.
I'll clean up the wording and post pictures when I get a chance today.
Re: AO Smith motor rebuild
Posted: Thu Oct 15, 2015 12:47 pm
by JPG
richardrouse wrote:I see now! Thank you sensei!
Sorry about the nomenclature. I know its maddening to try to help someone that doesn't know what the heck they are talking about.
I know why the switch actuator is riding too high, I took out a little spacer thingy that was in the front end cap out because I thought I was supposed to hear the armature on the switch moving. I, now, understand why that line of thought was totaly wrong.
I'll clean up the wording and post pictures when I get a chance today.
So the entire armature was positioned away from the start switch end? At what point did you remove it?
What you hear clicking is the actuator, not the switch.
Neglected to mention before, the actuator has 'hysteresis' (a fancy word for 'toggle'/'flip-flop'/'over the center' etc.). It flips at a given speed at startup, and flops back at a
slower speed.
Learn from this my little warrior (parts are usually there for a valid reason even though ye may not yet understand why).
Re: AO Smith motor rebuild
Posted: Thu Oct 15, 2015 4:36 pm
by jsburger
richardrouse wrote:The attachment 2015-10-15 16.12.05.jpg is no longer available
The attachment 2015-10-14 10.31.43.jpg is no longer available
The attachment 2015-10-15 16.12.05.jpg is no longer available
The attachment 2015-10-14 10.31.43.jpg is no longer available
Look closely at the bearing liner in this picture. There is the exact same spacer as in your last picture. It is a 1/2HP A O Smith motor from a 10ER.
Re: AO Smith motor rebuild
Posted: Thu Oct 15, 2015 4:43 pm
by richardrouse
JPG,
I didn't remove the black piece, without the spacer in the end cap, it wasn't positioned correctly, so it wouldn't hold down the contact on the start switch when at rest.
I have it all back together now and it runs reasonably well. The motor is a little noisy, but goes great in both directions.
Re: AO Smith motor rebuild
Posted: Thu Oct 15, 2015 4:45 pm
by richardrouse
Mr Burger,
Yes! I did notice that before. That was one of the things that made me realize that I had made a great and greivous error by removing it completely!
Re: AO Smith motor rebuild
Posted: Thu Oct 15, 2015 6:45 pm
by JPG
You will likely find that spring behind most bearings(even the belt sander). It presses against the outer race to allow slight movement as the temperature changes or from any other 'need'. The motor output shaft end is typically solid.
I question the lack of that spring to be 'the culprit'.
I am unclear at how the weights move out and how the motion(returning in) is translated to pushing the actuator.
i.e. I am unconvinced this is 'over'.
Re: AO Smith motor rebuild
Posted: Thu Oct 15, 2015 7:35 pm
by jsburger
JPG wrote:You will likely find that spring behind most bearings(even the belt sander). It presses against the outer race to allow slight movement as the temperature changes or from any other 'need'. The motor output shaft end is typically solid.
I question the lack of that spring to be 'the culprit'.
I am unclear at how the weights move out and how the motion(returning in) is translated to pushing the actuator.
i.e. I am unconvinced this is 'over'.
I am not sure what you mean that the output shaft end is typically solid. The pre-load spring washer in the A O Smith 1/2HP motor is on the output shaft end.
FWIW, the F-5 aircraft generator has a stack of Belleville washers (spring washers) in the bearing liner on the output shaft end.
Re: AO Smith motor rebuild
Posted: Thu Oct 15, 2015 9:19 pm
by richardrouse
It lives!it runs, and changes speeds. I think the centrifical switch is funky, but I can get it to run.