motor issues

holsgo · Post by **holsgo** » Tue Jan 24, 2012 8:58 am

I'm posting this here even though it's not s shopsmith motor and I know you motor guys are patient. I just bought a metal lathe. This motor runs. But, I can run it for some time, shut it off and it will click. It will then run again no problem. Some times, I will run the motor, not hear a click and if i try and run in that time it will hum. A minute later it will click and then be able to run.
So, I'm posting this here because I'm generally a motor idiot. I can do things but I've seen JPG and Bill help with motor questions so here goes.
What exactly is letter A? B is the switch and C is power in.
[ATTACH]15899[/ATTACH]
D and E are what?
[ATTACH]15900[/ATTACH]
F can be removed right and I can clean the fan?
[ATTACH]15901[/ATTACH]
Is the probem I'm describing a centrifugal start switch, Thermal switch? Capacitor?
Need a bit of help on this. Notice that D is abraded. Is there reason to go in there? What should I clean and lube?
Ge motor
Rpm 1725
Time rate Cont
Code L
CY 60
Temp rise 55c
Pw 1
Fr 56
Sf 1.0

wa2crk · Post by **wa2crk** » Tue Jan 24, 2012 9:22 am

Sounds to me that the centrifugal switch has gotten clogged over time. The switch has to have the freedom to move properly.
In the case of your motor it appears that the start switch may be a relay under box "D". The item under box "E" is most likely the start capacitor but I don't think that the capacitor is the main culprit. Cover "F" should not be removed because it looks like it is the end cover of the motor (which holds the bearing and the armature shaft) and if it is removed the armature will be free to come out of the motor. If you are not comfortable dismantling and reassembling an electric motor do not remove "F".
The fact that the motor runs is a good sign. I suspect that the start relay is the main culprit.
If you are timid about opening the motor I would suggest that you contact a REPUTABLE electric motor repair shop near you and have the motor repaired. It would probably be worth the cost.
Let us know how you make out.
Bill V

holsgo · Post by **holsgo** » Tue Jan 24, 2012 9:33 am

Ok. Tonight I will go home and open D take a pic and post it.we can go from there. I'm ok dismantling anything as long as I have someone coach me. Motors like this are my last frontier. Engines, no problem...just about anything else, no problem. I've been in the shopsmith motor before but that was through the forum posts. Is the start relay and the centrifugal switch the same thing?

JPG · Post by **JPG** » Tue Jan 24, 2012 10:24 am

holsgo wrote:Ok. Tonight I will go home and open D take a pic and post it.we can go from there. I'm ok dismantling anything as long as I have someone coach me. Motors like this are my last frontier. Engines, no problem...just about anything else, no problem. I've been in the shopsmith motor before but that was through the forum posts. Is the start relay and the centrifugal switch the same thing?

An internal start switch and an external start relay perform a similar function, but in a different manner.

Of interest would be the source of the click(motor or 'D').

The absence of a click when powering down would be a precursor of a failure to start the next attempt. A click should also be occurring on start up, but is hard to hear over the motor running noise.

A pix of the innards of 'D' is needed at this point.

dusty · Post by **dusty** » Tue Jan 24, 2012 10:37 am

In addition to the starter relay (clicking), there could be a thermal relay involved. That could explain the delayed click after the unit has been running. Delaying a restart of a unit that could be hot.

If it starts every time whenever the unit has been sitting (turned off) for an extended period of time, I would relax my suspicion of the start relay.

On the Mark Vs, I can hear the relay click on and click off if I just listen for it.

holsgo · Post by **holsgo** » Tue Jan 24, 2012 11:59 am

So far it has started from cold every time. It is only after running it, stopping etc that at a random point the situation will occur. A pic of D is on its way when I come home.

wa2crk · Post by **wa2crk** » Tue Jan 24, 2012 12:38 pm

Dusty;
I agree with what you said but sometimes a relay can get gummed up and when the relay coil energizes it has enough current to pull the contacts but when current is released the return spring is not strong enough to return the relay to the resting position. The old pull in current and drop out current specs on relays. I have seen this symptom on numerous fire trucks and ambulances where relays are in dirty environments.
Bill

JPG · Post by **JPG** » Tue Jan 24, 2012 1:08 pm

Dusty: Your Mark V probably has a centrifugal start switch. I have not seen start relays on other than older GE and Mark VII motors. The mechanical switch is much louder than a relay picking or dropping.

Holsgo: A start relay picks when the motor start winding is 'generating' sufficiently to pick the relay and the relay picking disconnects the start winding from the start capacitor/input voltage source. If the start relay contacts do not remake when the motor stops, the start winding will not be energized when power is reapplied.

If something is interfering with the relay armature returning to normal or the contacts remaking the motor will act as described.

We may need observations of the relay/contact action when it is failing.

We are assuming "D" is a start relay enclosure. Correction!!! s/b A

"D" is a junction box for connecting the internal motor wiring to the external stuff.

"E" is a can covering the start capacitor.

I am going to assume the lathe runs both forwards and backwards, so "B" contains the fwd/off/rev switch.

beeg · Post by **beeg** » Tue Jan 24, 2012 1:14 pm

Also it looks to be an older motor. Does it have oil holes?

holsgo · Post by **holsgo** » Tue Jan 24, 2012 1:32 pm

So A is what again? I will take a pic of D and A. The click sounds to be the motor. I'm beginning to understand what the click is. Now, as far as oil holes I will check. That's the next part of all of this, cleaning it out? Compressed air, oiling etc.
So a is a start relay enclosure and D is a junction box right?