Electrical Repair Questions? Ask an Electrician for Answers ASAP
Can you give me a photo of the diagram on the motor name plate? Upload using the paper clip icon on the tool bar.
if I could I would not be asking this question.
I may be able to get the diagram tomorrow...give me some time and I can probably get it. Check back tomorrow
5 wires white, black, green,red, orange
Ok, hang on
the problem is that a SB lathe works but sometimes the motor makes a noise, and if I do not switch it on and off until the motor runs mooth again it smokes. the motor is new and the lathe has noload on it.
I appreciate the help
It sounds like the capacitor is bad, have you replaced the motor already?
Is this the old motor that was unhooked?
Why is it unhooked and not written down?
The motor is newer and was replaced before I purchase it. I have worked on this lathe before it was mine with no problem. I can not see a tag because of the mounting of the motor. I would have to move it out away from a wall and then take have the lathe apart.
I meant half
Can you use a 'mechanic mirror' to see the diagram?
small mirror with a handle
I am a motorcycle mechanic, I know, the mounting plates of the lathe cover the motor plate
This was originally installed by an electrician, so I thought it would have been correct
Well, I have a motor diagram connection sheet that I am using here, but I can not be sure it's correct.
Let me ask..
The motor is running now the way it's connecrted?
But is having some intermittent issues?
yes, but sometime it makes a load hum and I have to keep on turning on and off until it stops, then it runs ok. It started to happen just in reverse.
Does it do this right when you turn it on...or when it's running already?
right when I turn it on, but not ever time.....
Ok, this is what is happening...
When the motor is first starting, right at the first one second, it has a set of contacts called the 'start winding contacts'
They are controlled by a centrifugal switch with two springs that open and close the contacts to the start winding when starting and stopping the motor
They close each time the motor is stopped. This sets the contacts so they are closed to the start windign for the next start
If they are dirty or hanging up, they don't close and that's when the motor humms when started
You need to blow out the back of the motor with compressed air and stick a small screw driver in the back of the motor and activate the centrifugal to open and close and blow it out good.
This is a fix that may or may not work, but it sounds like it's just a bit dirty and hanging up
I fo this fairly often and it save pulling it apart
what do u mean by putting a screw driver in the back and activate the centrifugal....where is it? what does it look like?
Look at the back of the motor and it has a cover with slots for air cooling
If you use a good flash light you can look in the back and see the centrifugal mechenism that opens and closes the contacts
It is weighted and has springs on either side that pull it back and forth when the shaft comes up to speed and slows down and stops. This opens and closes the contacts
If it's hanging up intermittently like yours, it will humm and not start when it's not closed for starting
That's why when you try it a few times, it finally moves back and closes the contacts...then it starts normal
I see this fairly often
I've fixed more than one motor doing this
I do have to open them up and work them over a bit sometimes too
U might not understand, the motor humms while it is running or makes more noise than normal. Then I turn it on and off until it runs quite again.
Or maybe I do not understand
You said above it does it when you try to start it
it starts humming
yes when I start it and it is running
That's when this happens
and after a little while it will smoke
It is trying to start with out the circuit to the start winding and it gets hot as hell instantly!
You're ruining the motor doing this
It's over heating it
I'm telling you what is wrong
I see this often I've been working on motors like this for 33 years!
Are you listening>?
the way you are wording this it sounds like I am just trying to start it, but the motor does start and does run. But now I understand we are talking about the same thing...right
I think so
the motor has two windings
it only uses one, the start winding for 1 second, then it's open by the switch. So if it happens right during start up...
then that's it.
Is that it?
right at starting?
the few seconds right there?
yes it happens right at starting and only stops after turning it on/off until its normal
ok, then this is correct what I'm saying about the centifugal, loo at this photo, I'm indicating the spring and centrifugal with the red line
click to open then agian to enlarge
it's a bit hard to see, it's small
but that's it, see the two springs?
Here is a close up...
yes, so unplug the motor(of course) and try to move these apart while blowing air into the area to remove debrib
There it is, that's the centrifugal device that operates the contacts
Yes of course
Here is the contacts the collar pushes closed
This is a set of contacts that power the winding
if they don't get closed because of the cent, it humms
This is what is wrong with your motor.
Give it a try...
Come back later...let me know..
thanks, I'll try in the morning
If you can use some electrical 'contact cleaner' and spry it out.