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  #1  
Old Sat 09 December 2017, 11:39
Kornerking
Just call me: Pete #127
 
Big Falls, Mn
United States of America
FIXED !! - Help.. uneven power out of the contactor. Now the z drive isn't working

What started as a seeming easy fix seems to have escalated.
First the machine faulted when the router came on. When it popped the program kept going but steppers stopped moving. I figured it might be a faulty contactor so I switched that out. Same issue. I noticed that the steppers were running slow .
Then I found out that I was getting a reading of 144 volts one side, 106 volts on the other side of the contactor running to the power supply/transformer. Replaced the Antek transformer today. still uneven power. Now the z drive motor isn't moving. Still popping the contactor when the router is plugged in. I have checked the router, it is good. reading 140 volts though on that side.

x and y motors are running normal speed.

Any ideas?
BOB? pmdx-126
Geckos? 203v
Faulty motor? Nema 34
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  #2  
Old Sat 09 December 2017, 18:39
JamesJ
Just call me: Jim #104 (retired)
 
Kansas
United States of America
Sounds like your input power to the mechmate is not correct. Unplug the Mechmate from the wall and check the voltage at the wall receptacle. What voltage do you have on each side??
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  #3  
Old Sun 10 December 2017, 03:53
Kornerking
Just call me: Pete #127
 
Big Falls, Mn
United States of America
Already did that. Reading 125 each side. Reads that all the way until it comes out of the contactor.
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  #4  
Old Sun 10 December 2017, 08:54
JamesJ
Just call me: Jim #104 (retired)
 
Kansas
United States of America
Do you have a schematic for your mechmate that you could send me?
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  #5  
Old Sun 10 December 2017, 11:58
bradm
Just call me: Brad #10
 
Somerville(MA)
United States of America
It sounds to me like your neutral is not connected properly. You say you have 125 on each leg feeding in; 125 + 125 = 250. And you have 144 and 106 on the other side, also totalling 250. So the legs seem fine. If the neutral is floating on the load side, it will find some place partway between the legs based on the relative load resistances on each leg.

You further say that the contactor pops when the router is plugged in; plugging the router in would further affect the floating neutral, perhaps to the point that the contactor coil releases.

I'd look very carefully for a loose connection on the neutral all the way through, and/or meter it out.
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  #6  
Old Sun 10 December 2017, 15:00
Kornerking
Just call me: Pete #127
 
Big Falls, Mn
United States of America
Brad, you called it. Wish I had seen this 6 hours ago.
Finally worked through the system. Got everything running. Except a Gecko went bad. It's now on order. I wish my hardware store sold them.

Work is backing up. Paid for premium shipping.

Thanks for the input everyone. I'm a woodworker, not an electrician.
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  #7  
Old Mon 11 December 2017, 05:01
Kornerking
Just call me: Pete #127
 
Big Falls, Mn
United States of America
The beauty of the Mechmate is it is pretty much trouble free.
The problem with Mechmate is that because it is trouble free a person tends to forget the build process.
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  #8  
Old Mon 11 December 2017, 07:24
bradm
Just call me: Brad #10
 
Somerville(MA)
United States of America
Glad the mystery is solved. It's probably worth asking Gecko about shipping back the dead one for repair - you might end up with an inexpensive spare for the future.

In my mis-spent youth we did a lot of temporary power taps for mediocre bands in under maintained roadhouses. You get a feel for what every combination of botched power feeds does. The world has gotten a lot safer around electricity since then.
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  #9  
Old Mon 11 December 2017, 14:20
Kornerking
Just call me: Pete #127
 
Big Falls, Mn
United States of America
I wondered if it could be repaired. If not I may just order one to have as backup. Downtime is a killer. I didn't realize how dependent I had become on it.
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  #10  
Old Tue 12 December 2017, 05:41
MetalHead
Just call me: Mike
 
Columbiana AL
United States of America
I had the same floating neutral/ground issue on my house!! The only thing holding everything down was the dryer as this was the only plug with an extra ground. So when they dryer was plugged in all was great, it kept the neutral and ground on the same plane. When you unplugged the dryer it would blow lights and surge protectors all through the house. Took me several times unplugging the dryer to finally dig in and figure it out. I had to disconnect every wire in the inside panel to realize the neutral and ground were not connected properly. In the US neutral and ground run together. Was very hard to find and took a lot of hours of trouble shooting!! Pete , glad you found your issue !!!
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  #11  
Old Tue 12 December 2017, 08:52
bradm
Just call me: Brad #10
 
Somerville(MA)
United States of America
Mike, is this a relatively new dryer? And the neutral and ground are tied together in the dryer, but you have a four prong plug? There should be a jumper that ties them together that's supposed to be removed if you use a four wire tail; it's there for legacy installations that have a three wire socket/plug. There's about a zillion references to this on a search for "dryer neutral ground".

The general rule is that neutral and ground should be tied together exactly once, at the entrance panel, which is also where the actual connection to a ground spike should be. Every other location that has both a neutral and ground should keep them separate.

There's a lot of complicated specific subcases covered in the NEC that all go towards that general rule.
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  #12  
Old Fri 15 December 2017, 09:31
MetalHead
Just call me: Mike
 
Columbiana AL
United States of America
This is a old machine. I have not dug into the dryer wiring, but the way it was acting before I fixed it suggested they were tied together. That is why when I unplugged it the neutral was loosing its ground reference because it was broken (corroded into) at the panel.
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  #13  
Old Fri 15 December 2017, 09:33
MetalHead
Just call me: Mike
 
Columbiana AL
United States of America
I "stuck" this thread since it is a good topic.
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  #14  
Old Tue 19 December 2017, 13:24
IamDave
Just call me: Davey
 
Ball Ground, GA
United States of America
Bad Gecko

Quote:
Originally Posted by Kornerking View Post
I wondered if it could be repaired. If not I may just order one to have as backup. Downtime is a killer. I didn't realize how dependent I had become on it.
When I bought mine they came with a 3 year if I broke it an anyway warranty. Send it back for a new on. Dang good warranty.
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  #15  
Old Sun 24 December 2017, 09:07
Kornerking
Just call me: Pete #127
 
Big Falls, Mn
United States of America
Davey, it turned out to just be a blown fuse. Easy fix.
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