Jet 1442 Problem

[Joe]

I have the above woodturning lathe and it's been acting strangely all of a
sudden. The complete sequence of events.

- Lathe runs fine in the garage/shop, although not much time put on it.
(bought it new)
- All of a sudden, every time I try to turn it on, it trips the GFI it's
plugged into
- I use an extension cord to plug it into a non-gfi, and it works fine, for
a (very) little while
- Now, when i turn it on, (it's a capacitor start/capacitor run motor), it
doesn't kick over from the start capacitor to the run capacitor which is
usually accompanied by a definite "click" and a smoother run after it kicks
over.

questions:

Is this what happens when a capacitor (the start) goes bad? Or is there
something in the kickover that can/has gone bad?
The motor has very little run time, this seems very odd to have happened
already.
would the bad/going bad capacitor cause the gfi to trip every time?

Any help would be appreciated.

Joe

 

[George]

I have the above woodturning lathe and it's been acting strangely all of a
sudden. The complete sequence of events.

- Lathe runs fine in the garage/shop, although not much time put on it.
(bought it new)
- All of a sudden, every time I try to turn it on, it trips the GFI it's
plugged into
- I use an extension cord to plug it into a non-gfi, and it works fine,
for a (very) little while
- Now, when i turn it on, (it's a capacitor start/capacitor run motor), it
doesn't kick over from the start capacitor to the run capacitor which is
usually accompanied by a definite "click" and a smoother run after it
kicks over.

questions:

Is this what happens when a capacitor (the start) goes bad? Or is there
something in the kickover that can/has gone bad?
The motor has very little run time, this seems very odd to have happened
already.
would the bad/going bad capacitor cause the gfi to trip every time?

Any help would be appreciated.

The click is a centrifugal switch, normally. If the motor does not come up
to speed the switch won't trip. If the contacts (points) are fused, it
won't trip either. This can be remedied by cleaning the points with some
400 sandpaper. WITH THE THING UNPLUGGED AND A MINUTE OR TWO FOR COMPLETE
CAPACITOR BLEED.

Not sure if this is your problem, however. Have you given it a good blast
or two of air? The GFI trips if there's a short. Could be you've got some
gunk in there. I'd try that first. Not the kind of thing you want to do,
bypass a GFI. It's a safety device, after all.

 

[Joe]

The click is a centrifugal switch, normally. If the motor does not come
up to speed the switch won't trip. If the contacts (points) are fused, it
won't trip either. This can be remedied by cleaning the points with some
400 sandpaper. WITH THE THING UNPLUGGED AND A MINUTE OR TWO FOR COMPLETE
CAPACITOR BLEED.

Not sure if this is your problem, however. Have you given it a good blast
or two of air? The GFI trips if there's a short. Could be you've got
some gunk in there. I'd try that first. Not the kind of thing you want
to do, bypass a GFI. It's a safety device, after all.

I blasted the motor with air, I'm now going to pull the covers off of the
capacitors and blast that as well. hopefully that will cure the problem.
I'll also try to find the points you're talking about, although with the
small amount of run time, i *hope* that's not the problem.

Wasn't trying to bypass the gfi receptacle. just trying non gfi outlets to
try to pinpoint the source of the problem. At the time, I didn't know
whether the gfi had gone bad or not.

Thanks,

Joe

 

[tdup2]

The GFI will rip easily. The extension cord could also make it trip if not a
large guage... at least 12 and no longer than 25feet.

 

[Joe]

I agree, but it trips with and w/o extension cord. And the cord I used was
a 9' air conditioner ext cord, more than adequate. Also, there is the issue
that this started happening after everything working fine for a number of
months.

joe

 

[Joe]

Bill,

Thanks for the reply. Since it's a tefc, I was hoping to avoid what you're
suggesting doing, which is take it apart, but oh well. Guess that's a
project for tomorrow. Just how long do those capacitors hold a charge
anyway? Not looking forward to getting zapped.

jc

 

[Leo Lichtman]

Bill,

Thanks for the reply. Since it's a tefc, I was hoping to avoid what
you're suggesting doing, which is take it apart, but oh well. Guess
that's a project for tomorrow. Just how long do those capacitors hold a
charge anyway? Not looking forward to getting zapped.

^^^^^^^^^^^^^^^^^^^
The capacitor on a single phase motor is there to produce phase shifting, to
create a "fake" rotating field. Since it is on AC, I don't see how it would
wind up with a charge when the motor is off. However, in case I am wrong,
just use a grounded clip lead to short out any terminal before you touch it.

 

[William Noble]

if you think about it, the capacitor is across some windings to produce a
phase shift. Also, electrolytics have a pretty good leakage. Of course an
AC circuit can leave volts on a capacitor, it just depends where in the AC
cycle you turn it off - but I wouldn't worry - unplug and take it apart, by
the time you get it apart, the cap will be discharged. But, the cap is an
electrical part, it doesn't care about dust - you can pack it in dust and
nothing will happen unless the dust has a lot of water and shorts it out-
more likely welded contacts or dust keeping them from opening, or a broken
wire inside the motor.

 

[Joe]

Capacitor start motors are notorious for tripping GFI receptacles. GFI
receptacles are typically designated for use with portable hand held
tools, which a lathe is not.

Do you think I would be better off removing the GFI receptacle and
installing a GFI breaker instead?
The garage is on one breaker, and the gfi is upstream of the rest of the
receptacles. Are the GFI breakers less finiky than the receptacles?
I should probably just put in a sub panel, but I don't think I have the
room.

thanks,

Joe

 

[Joe]

I'd solve the problems one at a time. Why does the motor not work? As I
remember, it doesn't work on a non-GFI circuit either?

Bill

Quite right.

jc

 

[Joe]

Everyone,

Thank you for your responses. I've learned a lot and taken a lot of advice.

I opened up part of the motor today. Here's what I found:

Inside is immaculate, which I would have expected for a TEFC (hence the TE)
I now have an understanding of how the centrifigal switch operates, it was
operating smoothly, no fusing, no dust, no problem.
HOWEVER,
you almost have to see this to believe it. I posted two pics in
alt.binaries.pictures.woodworking.

A piece which should have been installed on the shaft was rumbling loose in
there. There's no way it ever made it on the shaft during manufacturing.

The only amazing part is that this thing ever ran while plugged into a gfi.
I guess eventually this piece contacted the housing and caused the short.

I'm going to put it back together and see if it runs without this piece and,
of course, I'll be following up with JET. Even if the warranty period is
out, this is a definate manufacturing defect.

I'll keep everyone posted with what Jet does.

Thanks again,

Joe C.

 

[Mike Berger]

Let's assume that it runs correctly when you reassemble it. What do
you want Jet to do?

Joe wrote:
....

 

[Joe]

Joe wrote:
...

Let's assume that it runs correctly when you reassemble it. What do
you want Jet to do?

If it runs correctly, nothing. Why would I want them to do anything?

I called them to learn more about this extraneous piece and how critical it
is. They were very helpful by the way and said to call them if the motor
doesn't run after I put it back together and they would try to help me out
even though the motor (and the entire lathe, for that matter) is out of
warranty.

It was certainly worth the call.

Joe C.

 

[George]

If it runs correctly, nothing. Why would I want them to do anything?

Because you'd always be waiting for the other shoe to drop. The piece came
from somewhere, perhaps somewhere structural. Failure could come without
notice. Accidental success is the bane of every repairman's existence.

I'm in a similar circumstance myself, having assembled my new drillpress
with two long bolts left over. Though identified in the materials list,
there were no instructions as to where to put them. It seems to run right,
but why would anyone cost-conscious include extra hardware? Waiting for an
answer from them.

 

[Mike Marlow]

Do you think I would be better off removing the GFI receptacle and
installing a GFI breaker instead?
The garage is on one breaker, and the gfi is upstream of the rest of the
receptacles. Are the GFI breakers less finiky than the receptacles?
I should probably just put in a sub panel, but I don't think I have the
room.

thanks,

Joe

FWIW Joe, all of my wall outlets in my garage are on ground fault outlets
and I've never tripped one with my tablesaw, my drill press, or my jointer.
I would not worry too much about the GFI's.

-Mike-

 

[Ben Miller]

Capacitor start motors are notorious for tripping GFI receptacles.
GFI receptacles are typically designated for use with portable hand held
tools, which a lathe is not.

On what do you base those statements? Where have you seen restrictions on
the type of loads that can be run from a GFCI?

It sounds like your motor incorporates a centrifigal switch which is not
opening because it is worn out or fused together, or full of crud.

That could trip a circuit breaker due to over current, but it won't trip a
GFCI circuit, as it is not a "ground fault".

Ben Miller

 

[Bud--]

I mean to say that the purpose of GFI protection at
the level of the outlet is targeted towards hand-held tools. That is why you
don't see a GFI on a washing machine. It is a stationary piece of equipment,
and the plug serves as it's disconnect for servicing.

I believe receptacles, including washer, within 6' of a sink require a
GFCI. Also in unfinished basement areas.