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Gerald_D
Registered
Username: Gerald_d
Post Number: 942
Registered: 11-2005
| | Posted on Tuesday, February 20, 2007 - 08:43 am: | 
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And then we need to get an umbilical from the gantry to the wall-mounted control box, still leaving a walking space to get around the table from all sides. Also, we need to get to a grounding/earthing point on the main table structure. We could have used "cable chain" but that is expensive for us. Our experience with a "hanging" loop has been good.
The upper conduit is the hanging/flexing/moving one. The lower section is just static across the floor (should have a cover plate over it).
If you go this route, the moving/flexing conduit must be split along its whole length - this allows it to twist as it flexes.....
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reza forushani
Registered
Username: Reza
Post Number: 48
Registered: 01-2007
| | Posted on Tuesday, February 20, 2007 - 11:25 am: |
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Gerald. I am jealous! I DON'T THINK i CAN COME ANYWHERE AS CLOSE AS THIS.
Would you explain the buttons please. What type, what they do, where they are wired to?
Thanks |
Gerald_D
Registered
Username: Gerald_d
Post Number: 944
Registered: 11-2005
| | Posted on Tuesday, February 20, 2007 - 11:44 am: |
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There are 3 button boxes - one on the y-car, one at each end of the gantry. They duplicate each other (with one small exception). Reason for three duplicates is to save walking around the "beast" to find a button.
The red mushroom head is the E-Stop. It kills everything. Cuts all power. Used when blood or flames are near.
Yellow is the gentle stop, or pause. Stops the movement with a controlled deceleration. Used when the phone rings, you need to go to the bathroom, or you can see that you going to hit a clamp soon.
The green button (between the yellow and red-estop) is "resume". When you finish the phone call, get back from the bathroom, or have moved the clamp.
The button box on the y-car has a fourth (black)button. Havn't wired it in yet. It is intended to start a z-zero program after a cutter has been changed.
The buttons are wired to the PMDX-122 card, while the E-stop has a second set of contacts to the main power contactor.
All of the above functions can of course be done from the keyboard, but we may have unskilled labour who will be forbidden to touch the keyboard. We sometimes run for days without the need to get to the keyboard at all - operator loads sheet, presses green button, every 15 minutes. If lunch hooter intervenes, press yellow. If scared, press red. |
reza forushani
Registered
Username: Reza
Post Number: 58
Registered: 01-2007
| | Posted on Friday, February 23, 2007 - 11:50 am: |
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GERALD, THANKS FOR ALL YOUR HELP
Can you explain whether these switches are momentary or not (what type) and where they are wired to? The PMDX or Relay. How are you using your relay? Thanks again |
Gerald_D
Registered
Username: Gerald_d
Post Number: 987
Registered: 11-2005
| | Posted on Friday, February 23, 2007 - 12:02 pm: |
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Green, yellow, (and black) are momentary, push-to-make (Normally Open) switches. Let go, and they open again.
The Red, E-Stop, are actually two switches side by side, under one button. They are push-to-break (Normally Closed). When you have pushed the knob it mechanically "latches". To release the knob, you have to twist it, or pull it out. Only after the knob is released, will the switch contacts "make" again.
All the switches are wired to the PMDX - except the second switch under the E-stop knob which is wired to the main power relay. The main power relay is different to the router relay. |
reza forushani
Registered
Username: Reza
Post Number: 59
Registered: 01-2007
| | Posted on Friday, February 23, 2007 - 12:06 pm: |
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what relay do you suggest for the main power realy? thanks |
Gerald_D
Registered
Username: Gerald_d
Post Number: 988
Registered: 11-2005
| | Posted on Friday, February 23, 2007 - 12:21 pm: |
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An electro-mechanical relay (not SSR) or a form of a relay called a "contactor". You need to know if you are working 110V, 220V or 3-phase. Suggest you get your local electrician to advise you on this. Please believe me that I am out of my depth for specifying stuff for American power circuits. There is quite a difference in the way that your buildings are supplied. This relay is your "main switch" that has to switch off when blood starts flowing - don't trust a guy at the bottom end of Africa to pick it out for you. |
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60. Cable Management & Wiring