Electric Motor Troubleshooting...???

[WoodieSC]

My wife's L'Equip Model 221 Juicer started kicking out the GFI's in the kitchen. At one point in the past it had kicked out one of them, but not the others, so I had changed out that GFI and it seemed to solve the problem. She stopped using the machine for a few years so didn't think any more about it.

She started using it again about a week ago with an occasional 'kick out' that she didn't mention to me. But now it kicks out every one... AS SOON AS I touch the plug prongs to any of the four sockets along the counter (2 GFI's, 2 standard sockets with each one connected to one of the GFI's - 2 separate circuits). It is a 3-prong plug and cord.

The odd thing (to me) is that I don't even have to turn the motor on.

I'm assumingthat's telling me that there's a short somewhere in the motor, but there is absolutely nothing obviously out of kilter when I opened it up. The capacitor, the control board, the on/off switch, the safety switch, the motor rotor and the windings all look brand new. There are no melted spots on any of the wire insulation. None of the visible sections of the windings show any indication of any hot spots, etc. I can't find any brushes, so that's moot.

What should I be looking for, and what tests should I run? I tried to check the ohms of the capacitor but didn't get any so not sure about that.

The motor is a 120vac, 2.9A. The capacitor is listed as a 250vac and 16u. I've only found similar (rectangular, not round or oval) ones with 15, or 20u, so not sure I could replace it even if I need to, but it looks brand new.

Any ideas or suggestions?

Thanks.

[Smilee]

Well first off I would put I back together and plug into a non-gfic receptacle. This may solve the issue. Sounds like a shitty receptacle.

[Rubberhead*]

Is the plug two or three pronged?

[WoodieSC]

Well first off I would put I back together and plug into a non-gfic receptacle. This may solve the issue. Sounds like a shitty receptacle.

I did replace the initial GFI receptacle... twice... and it didn't help.

I also replaced the two circuit breakers in the panel... and it didn't help.

The circuits also kick out the GFI's when I plug the motor into the adjacent NON-GFI receptacles... and each of them are on separate circuit breakers.

I can test your theory with some other non-GFI circuits in the house, but I don't know why a 2.9A motor would kick out GFI's if there wasn't something wrong with it, especially when the motor doesn't have to be on to do it. Can anyone explain that?

Sorry, it is a 3-prong grounded plug.

Fwiw, I have also tested the various receptacles with a plug-in circuit tester and every one checks out.

[Rubberhead*]

Sorry, it is a 3-prong grounded plug.

I think you've got a short in the juicer. A GFI measures the current leaving on the hot line and the current on the return, neutral, line. If all is well the magnitude of the current leaving and the current coming back will be identical.

If the current leaving is not coming back in the neutral then it's sneaking out to ground through an unintended path. With a two pronged power cord, the current has to be sneaking out through something that's grounded (like a person).

In your case, I think the current is returning through the ground wire that goes to the rounded pin in a three-pronged cable. Since you're not blowing the regular breakers, the short is between the neutral and the ground rather than the hot and the ground.

If you have an ohm meter check the resistance between the neutral and ground prongs on the plug <- DO THIS WHILE IT IS NOT PLUGGED IN, of course...

If the resistance is low (near 0 ohms), then you've got a short somewhere between neutral and ground.

[Palmetto Bug]

What is that dangling green wire supposed to be connected to?

With the switch off, do you get any continuity between either flat plug prong and the body (ground)?

Switches and motors aren't hard to check but circuit boards can be voodoo.

[WoodieSC]

I think you've got a short in the juicer. A GFI measures the current leaving on the hot line and the current on the return, neutral, line. If all is well the magnitude of the current leaving and the current coming back will be identical.
That's what I've been thinking... neutral vs ground, probably.

If the current leaving is not coming back in the neutral then it's sneaking out to ground through an unintended path. With a two pronged power cord, the current has to be sneaking out through something that's grounded (like a person).

In your case, I think the current is returning through the ground wire that goes to the rounded pin in a three-pronged cable. Since you're not blowing the regular breakers, the short is between the neutral and the ground rather than the hot and the ground.
Got it. The trick will be to find it.

If you have an ohm meter check the resistance between the neutral and ground prongs on the plug <- DO THIS WHILE IT IS NOT PLUGGED IN, of course...
I've got ohm meters, will reassemble the unit and post in a minute...

If the resistance is low (near 0 ohms), then you've got a short somewhere between neutral and ground.

I'm reading '0' between the ground prong and both plugs, with the motor switch in both the on and off positions.

As a check, I did the same with the 3-prong plug of the large KitchenAid mixer and I also get '0' doing the same thing and that appliance works fine.

What am I doing wrong?

What is that dangling green wire supposed to be connected to?
The 'dangling green wire' is the ground wire and is held by the closest screw that holds the rotor in position.

With the switch off, do you get any continuity between either flat plug prong and the body (ground)?
Switch off, there is no continuity between either flat plug and the body of the motor.

Switches and motors aren't hard to check but circuit boards can be voodoo.

For all intents and purposes, I can't find any reason this motor is kicking out the GFI's.

Just out of curiosity, I cleaned a few more spots of 'old juice' that had leaked down into the unit and then plugged it into both GFI and non-GFI sockets and now the darn thing runs without kicking any of them out!

At this point, it would seem that a little bit of "juice gunk' has been the culprit. That doesn't seem to make much sense, but that's what it looks like... ????

[turbo]

Fuck a GFI.

[WoodieSC]

Fuck a GFI.

LOL... yeah, except when they save your life in a nano-second response to a short.

It still doesn't make any sense that this whole problem would be created 'just' by a GFI. This was the ONLY appliance used in 20 years here that has kicked those two circuits out, so I have to believe that there was something with the appliance's electrical system causing it.

We'll find out soon enough if it starts happening again. It took a few years of usage to get what little 'goop' was inside the motor housing, so IF that was the cause she'll be good-to-go for quite some time. IF it was something else that somehow I 'fixed' and don't realize it, it may show itself again soon.

[turbo]

LOL... yeah, except when they save your life in a nano-second response to a short.

It still doesn't make any sense that this whole problem would be created 'just' by a GFI. This was the ONLY appliance used in 20 years here that has kicked those two circuits out, so I have to believe that there was something with the appliance's electrical system causing it.

We'll find out soon enough if it starts happening again. It took a few years of usage to get what little 'goop' was inside the motor housing, so IF that was the cause she'll be good-to-go for quite some time. IF it was something else that somehow I 'fixed' and don't realize it, it may show itself again soon.

Yeah, their life saving ability is well documented. Not.

What is well documented is that 1 in 10 GFCI outlets is bad out of the box. Maybe 1 in 12 on a good day. It's also well documented that they're expensive, they readily fail, fire ants LOVE to destroy them, etc.

I stand by my statement. Fuck a GFI.

If it weren't for the county, I wouldn't have those pieces of junk in my house. Fact.

[Relentlous]

Buy a new juicer

[WoodieSC]

Either you're a lot wealthier than I am... or I have more money than you because I take a little time to see if I can repair the products I buy instead of just tossing them out. The damn thing is the time it takes... which I'd guess you most likely have more free time as a result of your response.

[WoodieSC]

Yeah, their life saving ability is well documented. Not.

What is well documented is that 1 in 10 GFCI outlets is bad out of the box. Maybe 1 in 12 on a good day. It's also well documented that they're expensive, they readily fail, fire ants LOVE to destroy them, etc.

I stand by my statement. Fuck a GFI.

If it weren't for the county, I wouldn't have those pieces of junk in my house. Fact.

Interesting info. I'd never heard that before.

Rubberhead, what's your thoughts on my "0 ohms" readings, yet the machine suddenly not kicking out the circuits after I put it back together?

The ONLY things I can think of that I did was to clean the little bit of 'gunk' off parts of the inside, none of which was on the rotor or windings, etc... and essentially discharge the capacitor when I tried taking a reading from it.

The ONLY things I haven't put back together yet is to reinstall the moon clip on the top section of the shaft to hold the rotor in position and then screw the top plastic disc that the bowl snaps on to.

I'll admit it... I'm confused.

[DRDUCK]

Square D breakers and don't have to worry about them GFCI but I doubt that is the problem. Might have a bad winding or something

[Rubberhead*]

Interesting info. I'd never heard that before.

Rubberhead, what's your thoughts on my "0 ohms" readings, yet the machine suddenly not kicking out the circuits after I put it back together?

The ONLY things I can think of that I did was to clean the little bit of 'gunk' off parts of the inside, none of which was on the rotor or windings, etc... and essentially discharge the capacitor when I tried taking a reading from it.

The ONLY things I haven't put back together yet is to reinstall the moon clip on the top section of the shaft to hold the rotor in position and then screw the top plastic disc that the bowl snaps on to.

I'll admit it... I'm confused.

Sorry, I forgot about this thread until just now. The zero ohms means that the cord is good but you'll have to put the lug attached to the green wire back where it belongs and re-run the test. Make sure that the metal on the green-wire lug isn't touching something that it's not supposed to touch. (Sorry I didn't notice it was unconnected in the photo the first time I responded).

[WoodieSC]

Sorry, I forgot about this thread until just now. The zero ohms means that the cord is good but you'll have to put the lug attached to the green wire back where it belongs and re-run the test. Make sure that the metal on the green-wire lug isn't touching something that it's not supposed to touch. (Sorry I didn't notice it was unconnected in the photo the first time I responded).

I understand, and put things back together, with the ground wire secured to a motor case screw, so it should have worked.

I just retested the juicer. Keep in mind that I used the machine yesterday with no problems, on one of the same circuits it was kicking out last week.

I used a good multi-meter, and set the dial to Ohms - 'x10K' position. With the power switch in the 'On' position, and all of the clamps secured on the machine since one of them has a safety switch on it, I still got '0' readings on each of the flat plugs to the ground.

I did get readings between the power and neutral plugs - '35' with red lead on the power plug and '4' with the red lead on the neutral plug.

So my findings from the other day are the same (noted here)...

I'm reading '0' between the ground prong and both plugs, with the motor switch in both the on and off positions.

As a check, I did the same with the 3-prong plug of the large KitchenAid mixer and I also get '0' doing the same thing and that appliance works fine.

What am I doing wrong?

Ideas?

Thanks.

[BigBallin]

I had a very similar problem with some lights. 5-400W HPS lights, would trip the GPI with a few lights on regardless where I put em. Did the same on the GFI on the genny. Got a nice meter, got a nice 8ft multi plug ext cord and separated wires so I could loop one and check amps and such. Before I go on, I was ridiculously meticulous in installing these wires....I was hiding them well and took great care to make sure everything was right.
That being said, with no rhyme or reason it was tripping the garage gfi and the genny gfi. Different ones, different loads, made no damn sense. One would go at 9ish amps load and one at 11. After exhausting all ground leak possibilities, I nervously tied em all to the 21 amp lock in plug.....viola.....shitty gfi's is the best I could come up with since they constantly tripped at the same load with nothing to do with ground...Fuck a gfi

[Rubberhead*]

I did get readings between the power and neutral plugs - '35' with red lead on the power plug and '4' with the red lead on the neutral plug.

Where's the black lead when you took these measurements?

[WoodieSC]

Where's the black lead when you took these measurements?

The black (-) lead from the negative plug on the multi-meter was snapped on to the opposite plug blade. That is, when red was +, the black was snapped to negative.

I figured that the difference between the '35' and the '4' was going different directions through the capacitor. Right?

Btw, I rechecked the mixer again, with the plug unplugged and the power switch on, and still got '0' ohms between each set of plugs. I did see a little 'bump' and then back to '0' on one of the red to black connections, but couldn't amplify it or keep it constant, so I have no idea what that meant.

Thoughts?

[WoodieSC]

I had a very similar problem with some lights. 5-400W HPS lights, would trip the GPI with a few lights on regardless where I put em. Did the same on the GFI on the genny. Got a nice meter, got a nice 8ft multi plug ext cord and separated wires so I could loop one and check amps and such. Before I go on, I was ridiculously meticulous in installing these wires....I was hiding them well and took great care to make sure everything was right.
That being said, with no rhyme or reason it was tripping the garage gfi and the genny gfi. Different ones, different loads, made no damn sense. One would go at 9ish amps load and one at 11. After exhausting all ground leak possibilities, I nervously tied em all to the 21 amp lock in plug.....viola.....shitty gfi's is the best I could come up with since they constantly tripped at the same load with nothing to do with ground...Fuck a gfi

My GFI on my genny went 'tits up' a number of years ago and I haven't bothered spending the $200 to replace it. Hope I don't regret that some day, but they're supposedly supposed to be disconnected if you're powering the house panel with the genny anyway, which is all I use it for.

If I'm wrong on that, hopefully someone will correct me.