Tablesaw motor, 220V, magnetic starter.

Began acting badly this afternoon. When start button pushed, motor
moved about 5 degrees, hummed, dust collector on same starter poles
fired up normally...

Without power, motor turns freely with no sign of binding.

Both Caps looked OK, but I ran up the street to Grainger and got a new
start cap. New start cap does not solve the problem... And It
aggravates me because it is about 5% bigger than the old one and won't
fit back in the can, but we can fight that battle later.

I guess the next step is to get the motor out where I can work on it and
start pulling continuity tests on the windings.

Anybody see something I am missing?

It was over 90 in the shop today. The saw is over 10 years old, and has
been worked hard. Jet Cabinet saw. I think it is on it's third motor
starter. Last one had coil failure about 2-3 years ago.

Thanks for any advice, of course things are super busy right now.

"Stuart Wheaton" wrote in message
...
Tablesaw motor, 220V, magnetic starter.

Began acting badly this afternoon. When start button pushed, motor
moved about 5 degrees, hummed, dust collector on same starter poles
fired up normally...

Without power, motor turns freely with no sign of binding.

Both Caps looked OK, but I ran up the street to Grainger and got a new
start cap. New start cap does not solve the problem... And It
aggravates me because it is about 5% bigger than the old one and won't
fit back in the can, but we can fight that battle later.

I guess the next step is to get the motor out where I can work on it and
start pulling continuity tests on the windings.

Anybody see something I am missing?

It was over 90 in the shop today. The saw is over 10 years old, and has
been worked hard. Jet Cabinet saw. I think it is on it's third motor
starter. Last one had coil failure about 2-3 years ago.

Thanks for any advice, of course things are super busy right now.

You didn't mention it so I'm guessing you missed it. There's a
centrifugal switch inside the motor that puts power to the start
winding when the motor RPM is below a threshold.
Art

I guess the next step is to get the motor out where I can work on it and
start pulling continuity tests on the windings.

Anybody see something I am missing?

It was over 90 in the shop today. *The saw is over 10 years old, and has
been worked hard. *Jet Cabinet saw. *I think it is on it's third motor
starter. *Last one had coil failure about 2-3 years ago.

Two things or maybe three.

Motor starting contacts bad.
Motor needs cleaning out. It does usually help to blow out the motor
with air as often as monthly. If you get lots of dirt and sawdust out
with air cleanout you are not blowing it out enough.
And the start capacitor might be gone. Buy expensive ones for
replacement.
While the motor is out replace bearings. Motor turns freely is not
always an indicator of bearings OK.

Motor starters should last longer than your post indicates. Again buy
good ones. Minimum of twice the startrting cirrent. Allen Bradley is
always good if properly sized.

Possibly bad contacts on the starter. Some contacts are replaceable.
What brand sand size is the starter?

We are talking single phase are we not?

Start and maintain a regular schedule of checking the motor current.
Both start and run. Good indication of bearing condition.

Ebay sometimes has good buys on Starters. The coils are usually
replaceable.

Bob AZ

Thanks for any advice, of course things are super busy right now.


Stuart

Me again. What HP and single or 3 phase?

There are lots of choices on Ebay right now.

Bob AZ

Artemus wrote:
"Stuart Wheaton" wrote in message
...
Tablesaw motor, 220V, magnetic starter.

Began acting badly this afternoon. When start button pushed, motor
moved about 5 degrees, hummed, dust collector on same starter poles
fired up normally...

Without power, motor turns freely with no sign of binding.

Both Caps looked OK, but I ran up the street to Grainger and got a new
start cap. New start cap does not solve the problem... And It
aggravates me because it is about 5% bigger than the old one and won't
fit back in the can, but we can fight that battle later.

I guess the next step is to get the motor out where I can work on it and
start pulling continuity tests on the windings.

Anybody see something I am missing?

It was over 90 in the shop today. The saw is over 10 years old, and has
been worked hard. Jet Cabinet saw. I think it is on it's third motor
starter. Last one had coil failure about 2-3 years ago.

Thanks for any advice, of course things are super busy right now.

You didn't mention it so I'm guessing you missed it. There's a
centrifugal switch inside the motor that puts power to the start
winding when the motor RPM is below a threshold.
Art



Give the man a prize! How 'bout that little stuffed dog on the top shelf!

The last time I tried to fiddle with a centrifugal switch, I hated it,
but this one turned out to be very easy to get to.

The motor designer and I obviously have different opinions on what
"Totally enclosed" means. That end cap was full of sawdust and plastic
fluff. I blew it out, and then lightly filed the burned contacts and it
is now running like new.

Thanks for the help.

Stuart