Grizzly G0490X motor trouble

Melinapex

Mark
User
Was using my jointer and went to turn it on and all I got what a clunk from the switch and a faint hum from the motor. Spoke with grizzly and replaced the capacitor (twice) and the centrifugal switches. Same result. The motor spins freely when I spin it by hand, but I cannot get it to start if I turn the power on and try to spin it. I did spend a lot of time with the grizzly tech and a multi meter testing all the parts of the switch, so that checked out.
I am at a loss, and grizz is out of ideas. So it's either take it to a shop, or buy a new motor, which grizz will sell me for $295. Not sure I want to buy another one of these as this one only lasted 8 years. Meanwhile, my Delta contractor saw still hums along at age 25......

Before I randomly pick a motor shop in Raleigh I figure with all the experience here at ncww someone has had a similar problem, and or can recommend a repair shop. Thanks in advance.
 

Ecr1

Chuck
Senior User
Just seeing how much you checked with your meter. Wiring schematic shows only a few components. Mag switch, control panel, motor and start and run caps. Do you have voltage to the motor on both legs.
 

Melinapex

Mark
User
Sorry but I am not quite sure what we were doing - I have zero knowledge when it comes to most anything electronics. We spent time inthemag switch and control panel. He would tell me where to probe, and I would tell him what the meter read. Everything we tested was ok. I do recall getting voltage numbers in the switch that were correct. That's all I can remember..
 

Oka

Oka
Corporate Member
I believe that is a split phase motor. Basically, there are only a couple of things that destroy the motor. Usually, one of the windings is shorting, or there is a failure in the armature. There is not much to these kind's of motors. ALWAYS Disconnect the power...... I have to say that because my brainiacs at work often will not follow proper safety procedure... go figure.

To troubleshoot the split-phase motor, This is the standard procedure sequence:
  1. Turn power to motor OFF. Visually inspect the motor. Replace the motor if it is burned, the shaft is jammed, or if there is any sign of damage.
  2. Check to determine if the motor is controlled by a thermal switch. If the thermal switch is manual, reset the thermal switch and turn motor ON.
  3. If the motor does not start, use a voltmeter to check for voltage at the motor terminals. The voltage should be within 10% of the motor's listed voltage. If the voltage is not correct, troubleshoot the circuit leading to the motor. If the voltage is correct, turn power to motor OFF so the motor can be tested.
  4. Turn the handle of the safety switch or combination starter OFF. Lock out and tag the starting mechanism per company policy.
  5. With power OFF, connect the Meter to the same motor terminals the incoming power leads were disconnected from. The ohmmeter will read the resistance of the starting and running windings. Since the windings are in parallel, their combined resistance is less than the resistance of either winding alone. If the meter reads zero, a short is present. If the meter reads infinity, an open circuit is present. In either case, the motor should be replaced. Note: The motor size is too small for a repair to be cost efficient.
  6. Visually inspect the centrifugal switch for signs of burning or broken springs. If any obvious signs of problems are present, service or replace the switch. If not, check the switch using an ohmmeter.
Hope that helps.
 

bob vaughan

Bob Vaughan
Senior User
Maybe you already tried this but...

The centrifugal switch, at rest should just push the contacts closed (lower photo). The centrifugal switch mechanism sometimes gets loose because of the soft metal they use. The switch will ride up on the shaft and not let the contacts be closed when the motor is at rest.

1  TPOS motor - 1.jpg

Centrifugal switch mechanism

1  TPOS motor - 2.jpg

Contact points for the starting windings. These should be closed when the motor is at rest.
 

Phil S

Board of Directors, President
Phil Soper
Staff member
Corporate Member
I looked at the wiring diagrams online. If they are accurately represent what you have, I see they are using a three-phase magnetic starter but only energizing two legs. I have been told all three legs need to have power or the switch will fail prematurely. This is normally done with a loop, You feed leg 1 and output to the motor on leg 1. Then you feed leg 2 but the output of leg 2 loops back to the input of leg 3. Then the output of leg 3 goes to the motor. My Unisaw, MiniMax and Hammer starters are all wired like this. The photos online do not show this. I am in Raleigh and would be willing to come over and take a look
 

Melinapex

Mark
User
Maybe you already tried this but...

The centrifugal switch, at rest should just push the contacts closed (lower photo). The centrifugal switch mechanism sometimes gets loose because of the soft metal they use. The switch will ride up on the shaft and not let the contacts be closed when the motor is at rest.

View attachment 193695
Centrifugal switch mechanism

View attachment 193696
Contact points for the starting windings. These should be closed when the motor is at rest.
Yup, that's all new.
 

Melinapex

Mark
User
I looked at the wiring diagrams online. If they are accurately represent what you have, I see they are using a three-phase magnetic starter but only energizing two legs. I have been told all three legs need to have power or the switch will fail prematurely. This is normally done with a loop, You feed leg 1 and output to the motor on leg 1. Then you feed leg 2 but the output of leg 2 loops back to the input of leg 3. Then the output of leg 3 goes to the motor. My Unisaw, MiniMax and Hammer starters are all wired like this. The photos online do not show this. I am in Raleigh and would be willing to come over and take a look
Thanks Phil, I will take any help you can give. Just let me know when you will be in the Apex area and we will set up a time. Still have about six angels to make to get twenty for you, should be done next week. Thx.
 

bob vaughan

Bob Vaughan
Senior User
Yup, that's all new.
When I've encountered those Asian-made motors with starting problems, I'll loosen the setscrew on the centrifugal switch and remove it. I'll look at the motor's shaft to see if I can see a dimple where the setscrew was originally. Then I'll slide the switch back on the shaft and align the hole with the dimple and measure how deep it is on the shaft. I'll install the setscrew and slide the centrifugal switch down to that dimension and try to start the motor. Often that's all it takes.

With any subtle electrical flow problem, you won't ever know what the problem is until something you try fixes it.
It can be as simple as a loose wire in the plug or other connecting point. Sometimes the slip-on connectors to the capacitor get loose and give fits until the loose connection gets identified.
 

tvrgeek

tvrgeek
User
I think Phil avd Boib are on it. Switch misadjusted. Humm means current through the main winding. Usually.

If on a odd chance you do need a motor, they are generic and you don't have to buy from Grizzly.
 

Phil S

Board of Directors, President
Phil Soper
Staff member
Corporate Member
Thanks Phil, I will take any help you can give. Just let me know when you will be in the Apex area and we will set up a time. Still have about six angels to make to get twenty for you, should be done next week. Thx.
Lets get your planer running. How about noon tomorrow? PM your address and THANKS for making angels
 

Melinapex

Mark
User
Lets get your planer running. How about noon tomorrow? PM your address and THANKS for making angels
Sadly, I have meetings stacked up tomorrow and either side of lunch hour on Friday. Work once again gets in the way of quality woodworking time..... even working from home.... I know you have an angel making class at your shop on the 9th. I'll pm you some times that can work and we'll figure out a time. Thanks a bunch..
 

Melinapex

Mark
User
When I've encountered those Asian-made motors with starting problems, I'll loosen the setscrew on the centrifugal switch and remove it. I'll look at the motor's shaft to see if I can see a dimple where the setscrew was originally. Then I'll slide the switch back on the shaft and align the hole with the dimple and measure how deep it is on the shaft. I'll install the setscrew and slide the centrifugal switch down to that dimension and try to start the motor. Often that's all it takes.

With any subtle electrical flow problem, you won't ever know what the problem is until something you try fixes it.
It can be as simple as a loose wire in the plug or other connecting point. Sometimes the slip-on connectors to the capacitor get loose and give fits until the loose connection gets identified.
Thanks for all the tips, I did follow the instructions they provide to position the new centrifugal switch after I replaced the contact points that sit in front of it. I know it is making contact but I can look to see if we have a dimple or maybe mess with the position a bit.... probably wait for Phil though - seems safer!
 

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