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  #151  
Old Sat 06 December 2008, 08:29
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
The leftmost two wires in my diagram need to be swapped. The very left wire is the common for all the pushbuttons, ie. ground. But, if you trace it up to the PMDX, it goes to the dedicated e-stop input.
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  #152  
Old Sat 06 December 2008, 10:10
gmessler
Just call me: Greg #15
 
Chicago IL
United States of America
Thanks for your help Gerald,

The mains e-stop is only 12v dc. Will that cause problems with the 5v circuits having it in the same cable? I could eliminate one of the prox sensors (don't think the z is that important) and run it in that cable.

Good catch on the e-stop / common swap. It was the last thing I finished up at 1am before I submitted the pic. I'll make that change.

Brad,

The transformer is only powered when the mains switch is turned on. It can't be powered by the contactor because it's powers a "NO" relay that the ON/OFF circuit goes through. Kind of a catch 22 - can't turn the power on until the relay is energized but can't energize the relay until the power is turned on. That's why I powered it after the mains switch so it can still be turned off.
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  #153  
Old Sat 06 December 2008, 10:14
domino11
Just call me: Heath
 
Cornwall, Ontario
Canada
Quote:
Originally Posted by gmessler View Post
The mains e-stop is only 12v dc. Will that cause problems with the 5v circuits having it in the same cable?
Greg,
That will not cause any problems. AC signals are the ones that radiate a lot of noise. The shielding on the dc signals is only to keep the ac noise out. Shielding on the ac lines help keep their noise in.
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  #154  
Old Sat 06 December 2008, 10:30
bradm
Just call me: Brad #10
 
Somerville(MA)
United States of America
Greg, my reading of your diagram is that the estop transformer is NOT part of the "start drives" circuit, and thus could be powered by the contactor, since the contactor is triggered by the start drives circuit, thus energizing the estop transformer as well as the rest of the "stop drives" circuit. No catch-22 ;-)
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  #155  
Old Sat 06 December 2008, 11:29
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Sorry Greg, I didn't look at the 12V stuff. Yes, 12VDC in that cable will be okay.
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  #156  
Old Sat 06 December 2008, 11:30
gmessler
Just call me: Greg #15
 
Chicago IL
United States of America
Brad,

Sometimes one can't see the forrest through the trees.

I went back and looked at the drawing and told myself he must be crazy....and as I repeated your words while running my finger over the diagram it hit me.

Thanks......

Heath,

I'm wondering if the second e-stop circuit should be in a different cable anyway. I'm probably waaaaay over thinking this one but suppose the hv e-stop ground were to short to the lv e-stop + very early in the cable (before any of the buttons). As far as the pmdx were concerned everything would be okay. But when you hit a stop button nothing would happen.
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  #157  
Old Sat 06 December 2008, 20:51
bradm
Just call me: Brad #10
 
Somerville(MA)
United States of America
You're quite welcome, Greg. It's a pet peeve of mine; I like knowing that when I hear that 'clunk' of the main contactor cutting out, there is no power at all left anywhere in the machine. (Related issue: providing bleed resistors for anything with big capacitors, though on a Mechmate, as Gerald points out, those resistors are called Gecko Drives).
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  #158  
Old Sat 06 December 2008, 23:08
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
If I understand this right, you are relying on a miniaturised 12VDC coil relay to open 120VAC contacts when you push an e-stop? I don't know if this is standard practice - I would check that relay out carefully to convince myself it is as reliable as a contactor. A contactor has a tough spring to open the contacts and a big coil to close them. That's what makes the satisfying "clunk"
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  #159  
Old Sun 07 December 2008, 20:25
gmessler
Just call me: Greg #15
 
Chicago IL
United States of America
Sounds kind of crazy doesn't it.

I tried looking up the coil draw on my contactor the Teco CN-16-F6 and can't seem to figure it out.
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  #160  
Old Sun 07 December 2008, 20:49
Greg J
Just call me: Greg #13
 
Hagerman, New Mexico
United States of America
Watching closely Greg,

This point of the project is "sleepless nights". Let me re-state that "FUN sleepless nights". If it wasn't fun, we wouldn't be doing it.

Your almost cutting.
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  #161  
Old Sun 07 December 2008, 21:28
jhiggins7
Just call me: John #26
 
Hebron, Ohio
United States of America
Greg,

Per your post:

Quote:
Originally Posted by gmessler View Post
Sounds kind of crazy doesn't it.

I tried looking up the coil draw on my contactor the Teco CN-16-F6 and can't seem to figure it out.
Did you notice this specification on the Factorymation site? See page 4, paragraph 4, Control Circuit Characteristics:

http://factorymation.info/motor_cont...N-9toCN-16.pdf

Looks like the energized power consumption is 12 VA. I don't know what "SEALED" means.

To get to the specification, click on CN-16-F6 on this page: http://74.125.95.132/search?q=cache:...lnk&cd=1&gl=us

Regards,
John
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  #162  
Old Sun 07 December 2008, 21:45
gmessler
Just call me: Greg #15
 
Chicago IL
United States of America
Hi Greg,

I can understand what you're talking about. The anticipation is killing me.

It's really painful waiting for parts (that should have been ordered sooner) to be delivered.

I'm also trying to figure out how Gerald knew about the lawn ornaments.
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  #163  
Old Sun 07 December 2008, 22:14
gmessler
Just call me: Greg #15
 
Chicago IL
United States of America
Thanks John,

Don't know how I missed that...

Looks like around 6 or so amps. That's good to know.

The relay I was going to use can only handle 6 amps. That's not enough head room for me. I may go with a contactor like Gerald recommends, or an auto relay like J.R. uses. Just happen to have one of those on hand.
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  #164  
Old Sun 07 December 2008, 22:32
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
12VA consumed off a 120V circuit means only 0.1 Amp (Volts X Amps = VA)

Inrush 70VA is the figure I would design for. Also make sure your relay's contacts open wide (and fast) enough to handle 120V.
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  #165  
Old Sun 07 December 2008, 23:31
gmessler
Just call me: Greg #15
 
Chicago IL
United States of America
I thought amps were RMS volts (volts *.707) / VA?

It makes sense that it should be able to handle the inrush current however it shouldn't ever see that. The start drives button should take that load then once released pass the hold current through the stop drives circuit.
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  #166  
Old Sun 07 December 2008, 23:39
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
VA is definitely Volts X Amps, equivalent to Watts.

Eg. think of a 500 VA power supply giving 10 Amp @ 50 Volt
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  #167  
Old Mon 08 December 2008, 06:44
jhiggins7
Just call me: John #26
 
Hebron, Ohio
United States of America
Greg,

Okay, I think I've finally spent enough time with your Control Box wiring layout to understand what you're doing.

First, as usual, Gerald is right. The INRUSH "current" at 120 volts would be 70 VA divided by 120 volts or about .6 Amps, i.e. 600 milliamps. That's not much of a challenge for most relays with contacts rated to switch 120 volts AC. So assuming your 12 VDC coil relay has contacts rated for switching 120 volts AC, you should be fine...you already said the contacts are rated for 6 Amps.

Second, I would like to revisit Brad's issue about leaving the 12V DC supply powered all the time per the following quote:

Quote:
Originally Posted by bradm View Post
I see that the 12V DC supply at the bottom for your LV EStop is powered all the time, rather than switched by the contactor. Is there a reason for that?
I saw your response, but I wonder if it's usual practice to turn off the Disconnect Switch between machine uses. It appears that the purpose of that Disconnect is to remove all power from the Control Box, not to turn on and turn off the machine. I would think that that switch would be normally left on unless opening the Control Box.

My plan is to turn on the 12 VDC power supply in parallel with the Contactor when the On Button (in your case Start Drives button) is depressed. It will be "latched" on by the same Contactor contact that latches the Contactor. Just a thought.

Regards,
John
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  #168  
Old Mon 08 December 2008, 09:14
javeria
Just call me: Irfan #33
 
Bangalore
India
HI John, I dont know if what Greg has done is right or wrong - but I have taken a similar approach.

I have a 24V DC power which is always on status when power is switched on to the controller. this powers the Estop, proximities, pause, start switches.

a key switch is used in series with estop to activate the contactor.

the reason behind using 24V is to have a common DC voltage powering all accessories wiithout trouble of facing a possible shock from the 220v supply.

I will be powering the 24V transformer with a 500mA fuse in between which will take care of any shorts on the small transformer end. and also any failure of the transformer will auto trigerr an estop.

ok wait I am I on topic, well still i will continue

The different inputs have opto isolated inputs to the BOB.

RGDS
Irfan
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  #169  
Old Mon 08 December 2008, 10:33
jhiggins7
Just call me: John #26
 
Hebron, Ohio
United States of America
Irfan,

I don't think there is a "right" or "wrong" on this point. I, along with, I am sure others, have become more aware of the "energy" cost of "always on" devices. So, the design I have been working on takes this into account.

Have you wired your 24 volt supply to be powered through the Disconnect?
If yes, do you plan to turn off the Disconnect between machine uses or do you plan to leave the Disconnect engaged and power on and off the table using the On Button and Off Button?

BTW, Irfan, I have followed your progress with great interest. Thanks for sharing.

Regards,
John
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  #170  
Old Mon 08 December 2008, 18:28
javeria
Just call me: Irfan #33
 
Bangalore
India
If I understand correctly the disconnect is the contactor - I will be switching it on and off thru a relay powered by the 24V supply,

the whole set up is put on - off by the rotary on off switch. (in my case it is wall mounted)

RGDS
Irfan
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  #171  
Old Tue 09 December 2008, 23:44
gmessler
Just call me: Greg #15
 
Chicago IL
United States of America
The 12/2 ga shielded cable showed up today.

It's a milspec M27500-12 SD2T23. The down side.....Not very flexible.....the individual wires are about the same as 12ga stranded thhn. That's not the least of it. After cutting off the outer jacket I noticed that the shielding was very black. when I cut off the inner jacket of the individual wires it was the same. It looks either VERY old or as though it sat in water. There were 37 strands in each conductor. I'm glad I only paid .35/ft

The 14/3 ga I received from Ebay is much more flexible. Each wire contains 40 strands. I went ahead and used the 14ga. It only has about 15ft or so to travel so I don't expect it to be a problem.
Attached Images
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File Type: jpg IMG_2558.JPG (34.6 KB, 718 views)
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  #172  
Old Wed 10 December 2008, 07:20
jhiggins7
Just call me: John #26
 
Hebron, Ohio
United States of America
Greg,

Thanks for the update. I was wondering if you had received that MIL SPEC cable.

Great pictures and analysis. Saved me from going down that same path.
The 14 ga. from Ebay looks good.

Regards,
John
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  #173  
Old Wed 10 December 2008, 14:39
domino11
Just call me: Heath
 
Cornwall, Ontario
Canada
Greg,
Sorry for the problems with wire #1. From the look of the tarnishing, it looks like the wire was silver coated. This is probably why it tarnished to black. Dont use this wire! Not a good idea to use it at all in this condition.
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  #174  
Old Sun 14 December 2008, 20:35
gmessler
Just call me: Greg #15
 
Chicago IL
United States of America
Good news....Got things running tonight!

I still have a lot of work to do but I do have the motors turning and axis moving..

I had to make a few changes to the wiring. First I needed to run a separate neutral wire to the router indicator light and to the power on light. I had the power light inline with the contactor coil and it didn't like that, and the way the router light was wired would have been 220v. I also realized that there was no need for the second 12v transformer so I made changes to that wiring as well.

The HV E-Stop works. I just need to test the LV E-Stop, pause and start butons. I also need to finish getting the prox sensors set up.

Now for the bad news. I got called out of town and won't be able to work on the MM for at least a week.

Here are some photos of my control box. I still have a little tidying up to do but for the most part it's finished. I will say that if I did it over again I would definately use a larger box.

Cheers.
Attached Images
File Type: jpg photo EP.JPG (65.3 KB, 657 views)
File Type: jpg photo EQ.JPG (41.5 KB, 659 views)
File Type: jpg photo ER.JPG (33.0 KB, 656 views)
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  #175  
Old Sun 14 December 2008, 22:06
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Well done Greg!

What are your control box dimensions?
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  #176  
Old Sun 14 December 2008, 22:53
gmessler
Just call me: Greg #15
 
Chicago IL
United States of America
Thanks Gerald,

The box is 20x16x8.....Inches that is. Granted my extremely oversized powersupply doesn't help the situation. I believe only 2 more inches height (width as viewed) would have made life much easier.

Last edited by gmessler; Sun 14 December 2008 at 22:53.. Reason: missed something
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  #177  
Old Mon 15 December 2008, 00:49
Alan_c
Just call me: Alan (#11)
 
Cape Town (Western Cape)
South Africa
Send a message via Skype™ to Alan_c
Good going Greg, nice work. (cutting before Christmas?)

I agree with you on the box size, my hands are just too big to work comfortably on all those closly spaced components, I would also go for a bigger box just to make working inside it easier.
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  #178  
Old Mon 15 December 2008, 07:15
domino11
Just call me: Heath
 
Cornwall, Ontario
Canada
Greg,
Looking good! Hope everything else goes well for you.
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  #179  
Old Fri 19 December 2008, 21:35
gmessler
Just call me: Greg #15
 
Chicago IL
United States of America
Thanks Alan & Heath,

Back in town tonight. Can't wait to get back to work on the MM. If I went out to the garage tonight I think the wife would make me stay out there.

Looks like tomorrow morning.

Missed the "12"

14?
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  #180  
Old Fri 19 December 2008, 21:36
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
*starts dusting off the #14*
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