Looking for the mythical reset button on my 1998 Unisaw
#11
My Uni decided it didn't want to turn on. 1 day it worked, then next, it's acting like it's unplugged. The manual that came with the saw is no help.

So far I have:
1) Checked circuit breaker and confirmed outlet had power.
2) Taken apart the switch and the inside was dust free, although I hit it with some compressed air for the fun of it.
3) Pushed and held the off button (with power to the saw).
4) Looked at the back of the saw for the reset switch.

Due to the side table, my motor access door opens ~4" before it hits a cross support of the table. The only way to get the door completely open is to take either the table or the door off. Before I do all that, I'd really like to know exactly where this mythical switch is. If it's on the back side of the motor that I can't see, I may be able to reach under and press it without disassembly.

Thanks for the help.
"73 is the best number because it's the 21st prime number, and it's mirror 37 is the 12th prime number, whose mirror 21 is the product of 7 times 3. Also in binary 73 is 1001001, which is a palindrome." - Nobel Laureate, Dr. Sheldon Cooper
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#12
The problem could be anywhere along the line, from a broken wire to a loose connection, or burned out switch contacts, or a failed capacitor, or failed centrifugal switch contacts,

The Unisaws of that era were available with a variety of motor starters from cheap to good.  A continuity test will be your best diagnostic tool.

If the motor has a reset button, it would most likely be on the junction box but that's unusual for a Unisaw motor.
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#13
Have you checked beyond the switch to make sure the motor is getting power? No noise at all is peculiar even for a bad motor, isn't it?
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#14
(08-23-2020, 08:02 AM)sniper Wrote: My Uni decided it didn't want to turn on.  1 day it worked, then next, it's acting like it's unplugged.  The manual that came with the saw is no help.

So far I have:
1)  Checked circuit breaker and confirmed outlet had power.
2)  Taken apart the switch and the inside was dust free, although I hit it with some compressed air for the fun of it.
3)  Pushed and held the off button (with power to the saw).
4)  Looked at the back of the saw for the reset switch.

Due to the side table, my motor access door opens ~4" before it hits a cross support of the table.  The only way to get the door completely open is to take either the table or the door off.  Before I do all that, I'd really like to know exactly where this mythical switch is.  If it's on the back side of the motor that I can't see, I may be able to reach under and press it without disassembly.

Thanks for the help.
Is this a magnetic starter ?   If so is it picking up when start button is pressed ?   The reset can be in the magnetic starter.  I don't understand 3)  (Pushed and held the off button (with power to the saw).   Roly
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#15
Does it look like this?  Mine's a '96.


   
Tom

“This place smells like that odd combination of flop sweat, hopelessness, aaaand feet"
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#16
Possibly a reset button on the motor itself? Other than that, check for power to the magnetic switch and make sure the buttons on the outside of the switch are contacting the actual reset button inside of the switch. Do you have power on the load side of the switch?
Waiting to grow up beyond being just a member
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#17
(08-24-2020, 09:15 AM)TDKPE Wrote: Does it look like this?  Mine's a '96.

Yes, it looks like that.

My #3 try was based on a suggestion in another thread, but the OP found the reset button on the back of his saw.

The original owner mounted the electrical box on the inside of the cabinet. I can't get to it, so not sure if that's where the "reset switch" is.
"73 is the best number because it's the 21st prime number, and it's mirror 37 is the 12th prime number, whose mirror 21 is the product of 7 times 3. Also in binary 73 is 1001001, which is a palindrome." - Nobel Laureate, Dr. Sheldon Cooper
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#18
(08-24-2020, 12:21 PM)sniper Wrote: Yes, it looks like that.

My #3 try was based on a suggestion in another thread, but the OP found the reset button on the back of his saw.  

The original owner mounted the electrical box on the inside of the cabinet.  I can't get to it, so not sure if that's where the "reset switch" is.

If you can't easily reach it, probably yes.


Laugh
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#19
(08-24-2020, 12:40 PM)Phil Thien Wrote: If you can't easily reach it, probably yes.


Laugh

Yeah, as I was writing that it dawned on me that if there was a reset switch, that'd be the place especially since I can't get to it easily.
Laugh

I suppose I should go out, take the access door off and crawl around in the sawdust so I can check. It's also very possible that the reset switch, if it exists, won't fix the problem.
"73 is the best number because it's the 21st prime number, and it's mirror 37 is the 12th prime number, whose mirror 21 is the product of 7 times 3. Also in binary 73 is 1001001, which is a palindrome." - Nobel Laureate, Dr. Sheldon Cooper
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#20
The overload portion of the control is in the control.  The little blue button.

But if you push the green start button and you don't hear the control clicking strongly, and releasing with the stop button, it sounds like there's an incoming power problem.  Check the top connections (L1 and L3), as they can loosen with use.  You need to get in there with your multimeter.

It's also possible the overload is tripped, though I don't know why it would trip when the saw isn't running.  A tripped O/L relay will prevent the start button from closing the main contactor since it's contact set is in series with the start/stop control.  BUT, it should be set to 'Auto' mode (the little dial in the middle).  If it's defective, nothing will happen when you push the start button.  


   

   

There should be no other junction box and/or O/L device between the control and the motor.
Tom

“This place smells like that odd combination of flop sweat, hopelessness, aaaand feet"
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