This afternoon I got a piece of ply jammed in my Unisaw. I got to the
switch before the breaker tripped but when I restarted the saw the
blade turned very slowly and then the breaker tripped.
The motor was not warm to the touch and there was none of the burning
smell that you would usually associate with a fried electrical part.
I'm hoping that the contacts on the centrifugal switch are a little
burned and will respond to some cleaning but thought I'd ask if anyone
here has had a similar problem before and what their thoughts might
be.
These motors are expensive, so I'd be willing to put a bit of time
into trying to fix this one.
(As a backup - who has the best prices on replacement motors?)
Thanks.
Regards, Tom
Thomas J. Watson-Cabinetmaker
Gulph Mills, Pennsylvania
http://users.snip.net/~tjwatson
After you get the blade out of the picture, see if it works after you spin
it. Could be a shorted capacitor.
Probably better to rebuild than repurchase.
"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> This afternoon I got a piece of ply jammed in my Unisaw. I got to the
> switch before the breaker tripped but when I restarted the saw the
> blade turned very slowly and then the breaker tripped.
>
> The motor was not warm to the touch and there was none of the burning
> smell that you would usually associate with a fried electrical part.
>
> I'm hoping that the contacts on the centrifugal switch are a little
> burned and will respond to some cleaning but thought I'd ask if anyone
> here has had a similar problem before and what their thoughts might
> be.
Good advice. Can't cost more to fix than to replace unless you've
actually fried it. Your description of running slow doesn't sound like
fried.
rhg
George wrote:
> After you get the blade out of the picture, see if it works after you spin
> it. Could be a shorted capacitor.
>
> Probably better to rebuild than repurchase.
>
> "Tom Watson" <[email protected]> wrote in message
> news:[email protected]...
>
>>This afternoon I got a piece of ply jammed in my Unisaw. I got to the
>>switch before the breaker tripped but when I restarted the saw the
>>blade turned very slowly and then the breaker tripped.
>>
>>The motor was not warm to the touch and there was none of the burning
>>smell that you would usually associate with a fried electrical part.
>>
>>I'm hoping that the contacts on the centrifugal switch are a little
>>burned and will respond to some cleaning but thought I'd ask if anyone
>>here has had a similar problem before and what their thoughts might
>>be.
>
>
>
On Wed, 22 Oct 2003 18:31:19 -0700, "George M. Kazaka"
<[email protected]> wrote:
>Tom Is it 3 phase???
>and if it is do you have it fused???
>
No, it's a 3hp single phase 220v model 83-651 with a 145ty-95 frame.
Regards, Tom
Thomas J. Watson-Cabinetmaker
Gulph Mills, Pennsylvania
http://users.snip.net/~tjwatson
My Unisaw did the same thing once, complete with slow down. Came back a
couple of hours later to start taking it apart and it came up running and
has never balked again. I wish you the same luck.
--
www.e-woodshop.net
Last update: 9/21/03
"Tom Watson" wrote in message
> This afternoon I got a piece of ply jammed in my Unisaw. I got to the
> switch before the breaker tripped but when I restarted the saw the
> blade turned very slowly and then the breaker tripped.
"Tom Watson" writes:
> This afternoon I got a piece of ply jammed in my Unisaw. I got to the
> switch before the breaker tripped but when I restarted the saw the
> blade turned very slowly and then the breaker tripped.
>
> The motor was not warm to the touch and there was none of the burning
> smell that you would usually associate with a fried electrical part.
I know the Unisaw uses a custom motor, but I must profess my ignorance as to
it's configuration.
Does this motor have a run cap as well as a start cap?
Your description fits a problem you would expect with a cap start, cap run,
motor.
HTH
--
Lew
S/A: Challenge, The Bullet Proof Boat, (Under Construction in the Southland)
Visit: <http://home.earthlink.net/~lewhodgett> for Pictures
"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> This afternoon I got a piece of ply jammed in my Unisaw. I got to the
> switch before the breaker tripped but when I restarted the saw the
> blade turned very slowly and then the breaker tripped.
>
> The motor was not warm to the touch and there was none of the burning
> smell that you would usually associate with a fried electrical part.
>
> I'm hoping that the contacts on the centrifugal switch are a little
> burned and will respond to some cleaning but thought I'd ask if anyone
> here has had a similar problem before and what their thoughts might
> be.
>
> These motors are expensive, so I'd be willing to put a bit of time
> into trying to fix this one.
>
> (As a backup - who has the best prices on replacement motors?)
>
> Thanks.
>
>
> Regards, Tom
> Thomas J. Watson-Cabinetmaker
> Gulph Mills, Pennsylvania
> http://users.snip.net/~tjwatson
First, Tom, it sounds like your whole saw is fried. I'll be coming by this
weekend to dispose of it in an enviromentally-safe manner. ;-)
Seriously, I'm with most thinking that the problem is outside of the motor.
However, if it ends up needing replacement,
I replaced a 3-phase motor in my DJ-20 (1.75HP) with a single-phase job
about a year ago. I tried going the route of finding a motor shop with a
used motor. I called three or four places with no luck. I was also told
that no one wastes their time rewinding motors under 10HP...YMMV. After a
lot of looking, I ended up finding a motor at my not-so-nearby Farm and
Fleet. It was actually made by the same company that made the original for
Delta (Marathon Electric). I don't know how high a HP rating they carry, or
if they carry it in the frame style you require.
I was also given recommendations to check out www.surpluscenter.com
Good luck,
todd
Tom Is it 3 phase???
and if it is do you have it fused???
You could of blown one fuse,
Or yes you could of burnt one of the heat couplers,
Either way you won't get that burning smell
and of course that why those things are their to protect the motor.
Good luck
let us know what you find
George
"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> This afternoon I got a piece of ply jammed in my Unisaw. I got to the
> switch before the breaker tripped but when I restarted the saw the
> blade turned very slowly and then the breaker tripped.
>
> The motor was not warm to the touch and there was none of the burning
> smell that you would usually associate with a fried electrical part.
>
> I'm hoping that the contacts on the centrifugal switch are a little
> burned and will respond to some cleaning but thought I'd ask if anyone
> here has had a similar problem before and what their thoughts might
> be.
>
> These motors are expensive, so I'd be willing to put a bit of time
> into trying to fix this one.
>
> (As a backup - who has the best prices on replacement motors?)
>
> Thanks.
>
>
> Regards, Tom
> Thomas J. Watson-Cabinetmaker
> Gulph Mills, Pennsylvania
> http://users.snip.net/~tjwatson
"Tom Watson"writes:
> Yeah Lew, it's a cap start/cap run. In the morning I'm going to check
> the starting cap and the centrifugal switch.
From you description, sounds like the motor has sufficient starting torque
but does not maintain speed.
That would lead me to suspect the run cap, not the start cap and switch.
Your local Grainger will have caps in stock, probably at the regional whse,
available within 24 hours worst case.
HTH
--
Lew
S/A: Challenge, The Bullet Proof Boat, (Under Construction in the Southland)
Visit: <http://home.earthlink.net/~lewhodgett> for Pictures
"Tom Watson" writes:
> I couldn't find my meter and so I took the caps to a local shop to
> have them tested. Tested good.
>
> Tomorrow AM will look at centrifugal switch.
OK, time for plan B.
You will need a means of testing for continuity.
Before taking the motor apart, chuck up the shaft in a drill motor, say
1,100 RPM minimum, 1,800 would be better, and do a continuity check across
the switch leads now that the caps are removed.
Start the drill motor. If you loose continuity, mech switch is OK.
If switch is OK, start chasing loose connections which will be sort of like
chasing smoke.
HTH
--
Lew
S/A: Challenge, The Bullet Proof Boat, (Under Construction in the Southland)
Visit: <http://home.earthlink.net/~lewhodgett> for Pictures
"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> On Thu, 23 Oct 2003 20:32:39 GMT, "Lew Hodgett"
> <[email protected]> wrote:
>
> >
> >"Tom Watson"writes:
> >
> >> Yeah Lew, it's a cap start/cap run. In the morning I'm going to check
> >> the starting cap and the centrifugal switch.
> >
> >From you description, sounds like the motor has sufficient starting
torque
> >but does not maintain speed.
> >
> >That would lead me to suspect the run cap, not the start cap and switch.
> >
> >Your local Grainger will have caps in stock, probably at the regional
whse,
> >available within 24 hours worst case.
> >
> >HTH
>
> Grainger has caps of the right specs but not the right form factor.
> They have mostly oval shapes and these are cylinders.
>
> I couldn't find my meter and so I took the caps to a local shop to
> have them tested. Tested good.
>
> Tomorrow AM will look at centrifugal switch.
>
> (will also buy new meter - sigh)
Tom,
Doncha just hate it when objects like that grow legs and walk away?
Thought I'd chime in on the motor though. Went back to the beginning of the
thread, and I'd be willing to bet(Oh, maybe 25 cents or so) that when the
saw jammed, the centrifugal starter switch welded itself shut. Now, instead
of spinning up and opening the start winding, it's trying to run on both
windings, which is causing the slow rotation and the breaker opening. I'll
bet it's making a rather loud "growling" noise too.
Just my $.02
Nahmie
On Wed, 22 Oct 2003 16:26:51 -0400, Tom Watson
<[email protected]> pixelated:
>These motors are expensive, so I'd be willing to put a bit of time
>into trying to fix this one.
>
>(As a backup - who has the best prices on replacement motors?)
Wood a 3 or 5hp HFT for $69.99 do ya, Tawm? 2hp for $60, too.
That Ewenisaur deserves no less!
Or have yours rewound for a benjy if it's not a cap/points.
Your call.
- Metaphors Be With You -
http://diversify.com Web Application Programming
On Thu, 23 Oct 2003 02:26:13 GMT, "Lew Hodgett"
<[email protected]> wrote:
>I know the Unisaw uses a custom motor, but I must profess my ignorance as to
>it's configuration.
>
>Does this motor have a run cap as well as a start cap?
>
>Your description fits a problem you would expect with a cap start, cap run,
>motor.
>
>HTH
Yeah Lew, it's a cap start/cap run. In the morning I'm going to check
the starting cap and the centrifugal switch.
Delta's motor is custom in that it has that funny mount on it, and the
shaft length and thickness are non-standard.
I'm hoping their capacitors are not proprietary.
Regards, Tom.
Thomas J. Watson-Cabinetmaker
Gulph Mills, Pennsylvania
http://users.snip.net/~tjwatson
On Thu, 23 Oct 2003 20:32:39 GMT, "Lew Hodgett"
<[email protected]> wrote:
>
>"Tom Watson"writes:
>
>> Yeah Lew, it's a cap start/cap run. In the morning I'm going to check
>> the starting cap and the centrifugal switch.
>
>From you description, sounds like the motor has sufficient starting torque
>but does not maintain speed.
>
>That would lead me to suspect the run cap, not the start cap and switch.
>
>Your local Grainger will have caps in stock, probably at the regional whse,
>available within 24 hours worst case.
>
>HTH
Grainger has caps of the right specs but not the right form factor.
They have mostly oval shapes and these are cylinders.
I couldn't find my meter and so I took the caps to a local shop to
have them tested. Tested good.
Tomorrow AM will look at centrifugal switch.
(will also buy new meter - sigh)
Regards, Tom
Thomas J. Watson-Cabinetmaker
Gulph Mills, Pennsylvania
http://users.snip.net/~tjwatson
I had nearly the same thing happen while resawing a large peice of wood. The
saw quit running and after a day would still not power up. I opened the
switch and pushed the start buttong with thecover off and now it works fine.
I have no idea why but I suppose the switch had some kind of protection and
just needed to be pushed all the way down which can't be done with the cover
on.
I do realize this sounds almost dumb, but it worked and no problems since.
Steve
"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> This afternoon I got a piece of ply jammed in my Unisaw. I got to the
> switch before the breaker tripped but when I restarted the saw the
> blade turned very slowly and then the breaker tripped.
>
> The motor was not warm to the touch and there was none of the burning
> smell that you would usually associate with a fried electrical part.
>
> I'm hoping that the contacts on the centrifugal switch are a little
> burned and will respond to some cleaning but thought I'd ask if anyone
> here has had a similar problem before and what their thoughts might
> be.
>
> These motors are expensive, so I'd be willing to put a bit of time
> into trying to fix this one.
>
> (As a backup - who has the best prices on replacement motors?)
>
> Thanks.
>
>
> Regards, Tom
> Thomas J. Watson-Cabinetmaker
> Gulph Mills, Pennsylvania
> http://users.snip.net/~tjwatson
On Wed, 22 Oct 2003 16:26:51 -0400, Tom Watson
<[email protected]> wrote:
>This afternoon I got a piece of ply jammed in my Unisaw. I got to the
>switch before the breaker tripped but when I restarted the saw the
>blade turned very slowly and then the breaker tripped.
>
>The motor was not warm to the touch and there was none of the burning
>smell that you would usually associate with a fried electrical part.
>
>I'm hoping that the contacts on the centrifugal switch are a little
>burned and will respond to some cleaning but thought I'd ask if anyone
>here has had a similar problem before and what their thoughts might
>be.
>
>These motors are expensive, so I'd be willing to put a bit of time
>into trying to fix this one.
>
>(As a backup - who has the best prices on replacement motors?)
>
>Thanks.
>
>
>Regards, Tom
>Thomas J. Watson-Cabinetmaker
>Gulph Mills, Pennsylvania
>http://users.snip.net/~tjwatson
http://www.electricmotorwarehouse.com/
http://woodworker.com/cgi-bin/search.exe
both have em the later sells baldor the first one has leeson and
others. none of em are cheep!!!!!!!!!!!!! 3 hp motors are reasonable
BUT the ones with the right mount and the 3/4" shaft cost ya double.
skeez
If you have no fuses in the wiring, look for the thermal protectors in both
the switch, and that connecter box that is usually on the back of the saw.
I have never had the problem of thermal protector in the motor itself but
if all else failed i would certainy look.
I've been known to lock up my unisaw a time or two or three, Its never shut
down on me,
But I have had the thermal protectors go on other 3 phase machines.
My compressor is 3 phase and it is also fused as well as a circuit breaker
and I have blown a fuse on that several times.
When you throw one leg on a 3 phase circuit some motors will do like you
said run slow, and some will just sit there and humm.
I doubt you blew the Motor unless that sucker is real old and tired,
I have 5 horse that is about 15 years old, and still chopping wood without
tiring.
I'm willing to bet its in the wiring systen someware as in fuses or thermal
protectors
I'll look at my wiring diagram when i go into the shop in the morning and
see where it could possibly be.
Good luck,
George
"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> On Wed, 22 Oct 2003 18:31:19 -0700, "George M. Kazaka"
> <[email protected]> wrote:
>
> >Tom Is it 3 phase???
> >and if it is do you have it fused???
> >
>
> No, it's a 3hp single phase 220v model 83-651 with a 145ty-95 frame.
>
>
> Regards, Tom
> Thomas J. Watson-Cabinetmaker
> Gulph Mills, Pennsylvania
> http://users.snip.net/~tjwatson