+ Reply to Thread
Results 1 to 10 of 11

Thread: Reset button

Hybrid View

  1. #1
    Join Date
    Oct 2007
    Posts
    4

    Default Reset button

    I have a Sears model 113.197751 table saw (1979). Under heavy load it shut down and won't restart. The reset button did not pop out and does not "click" when pushed.

    I pulled the motor and checked everything. The problem appears to be the rest button itself (p/n CGJ65EB). I can't locate the part on-line and Sears says motor work is a Service Center job.

    Does anyone know if or where I can obtain this part? Thanks.

  2. #2
    Join Date
    Aug 2007
    Posts
    1,131

    Default Re: Reset button

    Impossible to say from here exactly what the problem is......but it could be one several different potential problems.

    If you haven't already, check first to see that you have current to the saw motor as per the normal wiring it runs on; breaker hasn't tripped, wiring hasn't been compromised, any/all switches are working properly, etc. Heavy loads can easily take out/melt switches that aren't up to it because they were of marginal ability in the first place or aren't up to it anymore. Stuff wears out.

    If you find no fault there, I'd suggest you take the motor to a local electric motor repair biz. Hopefully you have one there and will find it in the yellow pages. Saves you all the shipping costs associated with a return to Sears. Warranty is up anyway, not? They can run a few quick tests with a meter on the motor wiring, windings and misc parts to ascertain exactly what is at fault.

  3. #3
    Join Date
    Oct 2007
    Posts
    4

    Default Re: Reset button

    Thanks for your response.

    The wiring is okay. In looking at the reset button I found an adjustment on the back side which got it "clicking" again. I reinstalled the button and the motor is now getting power.

    Unfortunately, the motor isn't turning. It sits and vibrates rapidly back and forth as though it can't make up its mind which direction to turn and changes its mind with each pulse of alternating current.

    I triple-checked all of the connections to the button, starter ballast, overload relay and motor, and all appears correct unless my pencil diagram was wrong.

    Any last thoughts before it goes to a shop?

  4. #4
    Join Date
    Aug 2007
    Location
    The Great White North
    Posts
    4,045

    Default Re: Reset button

    If you are 100% sure the wiring is correct especially for the capacitor , then I suspect all the problems seem likely to be a faulty capacitor.

    Here is a procedure for testing it :

    1- take a screw driver and bridge the two terminals of the capacitor ... this will discharge the cap. Start capacitors store electricity, that is why you need to discharge them .

    2-With an ohm meter set at the 1000 ohm ( 1k ohm ) if it's a selectable type ... auto ranging types won't matter.

    Touch the two terminals of the capacitor with your ohms meter test leads. The meter will display some numbers for a second then it will return to OL ( open line or infinity ).

    3- Reverse your ohms meter test leads on the two terminals and the same condition should happen.


    It should do this every time that you switch the ohms meter test leads position. If it does this the start capacitor is good.

    If the readings stay at a numerical value and doesn't go to OL or infinity , then the capacitor is faulty ... known as leaky.
    If it stays at 0 (zero) then the cap. is shorted. Either case the capacitor would need to be replaced with the exact same value.

    The reset switch is likely the thermally controlled type. In that when over heating occurs inside the motor it trips to open the circuit for the motor. A faulty capacitor will over heat the start windings and the life of the motor will be shortened due to overheated motor windings.

    Another possibility is there is shorted windings then the motor will have to be repaired or replaced. At least the above procedure is a cheaper and faster method of finding out.

    Hopefully this helps out
    Last edited by canuk; 10-03-2007 at 10:58 AM.

  5. #5
    Join Date
    Oct 2007
    Posts
    4

    Default Re: Reset button

    Thanks Canuk for the advice. I should be able to check the capacitor myself following your instructions.

    I will mention two things:

    1) There's a remote possibility that I switched two wires when reassembling the relay bus. For anyone with intimate knowledge of this motor the two wires are the black and yellow on the underside of the bus. I could describe the connections in much greater detail but probably no one out there has a wiring diagram for this motor anyway, so there's little point.

    2) The reset button appears to operate on centrifugal force. It looks as though a spring/counterweight system keeps a switch in the open position while the motor spins, and if the rpm drops below a certain point under load, the springs pull the counter balances away from the switch allowing it to close, thus tripping the reset button.

  6. #6
    Join Date
    Aug 2007
    Posts
    1,131

    Default Re: Reset button

    The centrifugal switch you refer does not likely have anything to do with thermal protection. Rather that switch is responsible for engaging and disengaging the start windings and/or capacitor.

    If the motor seems to attempt starting when you turn it on, but doesn't..... then most likely either.....1- the contacts on the centrifugal switch you refer to are either burned/carbonized/missing, 2- the start capacitor is kaputt, 3- the start windings are burned/fused together rendering them worthless, 4- the springs of the centrifugal switch are broken, weak or missing...or 5- the motor is incorrectly wired.

    (If you need one.......a new CS should be readily available at any motor repair facility)

    If the motor got too hot (thermal protection failed to trip in time) while doing heavy duty work, then the insulative coating that separates one wire of the windings from it's neighbors may have been melted/damaged. This would render the start windings inoperative. Park your nose close to the motor and see if it has even a slight burnt odor. This would not be a good sign, but you *might* be able to effect a repair. You'd have to disassemble the motor to some degree in order to attempt/perform a repair. Check the windings over closely for any signs of burns/melts. Sometimes these can be simply repaired, sometimes not. To attempt a repair you would very carefully separate the involved copper winding wires in the immediate area of damage from one another just a tad...... and then spray them with a can of aerosol varnish or lacquer....from all available angles of attack. Allow to dry overnight and push the wires back down tight to the rest of the windings. (This is the procedure I learned many years back when I worked at a GE motor factory here in Illinois and it has saved numerous motors from the junk pile. <G>)

    If such damage is extensive, the above may be futile.

    See these links and note that .............."Other split-phase motor characteristics: Maximum running torques range from 250 to 350% of normal. Plus, thermal protection is difficult because the high locked-rotor current relative to running current makes it tricky to find a protector with trip time fast enough to prevent start-winding burnout. And, these motors usually are designed for single voltage, limiting application flexibility."

    Also see the troubleshooting section near the bottom of the second link.

    http://www.iprocessmart.com/leeson/l...se_article.htm

    http://www.metalwebnews.com/howto/el.../elec-mtr.html
    Last edited by goldhiller; 10-09-2007 at 11:20 AM.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •