Jet 1442 Problem

return it for a new motor.

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

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.

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

Most likely -- your centrifugal switch is not opening. That switch is IN the motor so it must be taken apart to get to it. Sometimes air through the motor will do the trick but only sometimes.

If the start capacitor is bad (not very likely) it may not get the motor spun up enough to kick the cent... switch. In this case you may be able to spin it up by hand fast enough to kick it. That would prove that the switch probably working right but the capacitor is bad.

If under warranty -- take it back.

Three phase motors don't have any of that 'stuff' which goes bad in single phase motors. With the advent of less expensive vfds, somebody needs to come out with a motor/vfd retrofit kit for various lathes for those folks who are tired of screwing with capacitors and centrifugal switches. That would also give you the low rpm and reversing which are so sorely needed on so many Reeves drive equipped lathes.

Bill

Joe wrote:

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

^^^^^^^^^^^^^^^^^^^ 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.

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.

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. 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.

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

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

Joe wrote:

Quite right.

jc

Hi Joe, Not sure where this thread is going. All the responses give good reasons for your troubles and woes and are a helpful academic review of cap start-cap run single phase ac motor troubles, but if it's still in warranty IMHO, the most practicable advice for a _woodturner was to get a new motor or if not, consider taking it to a repair shop.

Turn to Safety, Arch Fortiter

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.

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

Joe wrote: ...

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.

How about something along the lines of supplying a motor that doesn't have this flaw? After all, it has caused the lathe to be inoperable and now we have a part missing from the motor that we don't understand the function of, which may or may not be of critical importance to the safe, reliable functioning of the motor. Also, damage to the motor may have occurred as a result of this part flopping around loose, which may have severely shortened the usable life of the motor, especially the windings.

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.