By now the mill is wired with fuses. There is two 20A fuses, for L1 and L2. From the fuses, I feed a 240->120v control transformer. Output of this transformer will be used, as part of the the estop circuit, as input to a coil of the main motive power contactor. I have installed the contactor and connected the VFD to it.
The point of this transformer is that even if only one fuse blows, there will be no power to the motive contactor's coil, so nothing will even possibly run.
More things to go on the DIN rail will be
1) 24vdc power supply
2) Ethernet switch
I will also put DIN terminals for various forms of power, like 24vdc,
110v isolated, 220v to motion drives (servo and VFD).
Yes, DIN rail is a nice form factor. One thing to note along those lines, is that if you need to add any custom circuitry, you can get DIN rail mount enclosures with built in terminal blocks to house your custom stuff. You can find them on DigiKey.com and probably other places.
Yes, DIN rails, Panduit duct and printed labels all make for a very neat and serviceable installation. Don't forget to label both ends of any wire. A stick-on document pouch stuck inside the compartment door with detailed diagrams is also a big help.
They typically have their own built-in fuses anyway.
Hmm ... since the VFD can bring the spindle to a stop before the inertia would spin it down with no power to the VFD, but it is possible to have failures which would leave the VFD running anyway -- what I would suggest is to signal the VFD to stop, then pause about twice the ramp-down time and drop power from the VFD. There are DIN socketable TDRs (Time Delay Relays) which can be set for anything from about a fraction of a second to at least an hour.
*Nice*. I didn't know that they made industrial strength switches. The only question which comes to mind is how many things in there need to communicate with each other via ethernet? I would have thought that the sole purpose of the ethernet here is to move G-code or CAD files from the system on which they were developed to the system running the machine tool.
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Hmm ... I think that the forms of labels for this are better for wire labeling than what a Brother will produce. I've used some Brother labels (in a Kroy labeler) to label wires -- and had problems with the labels sticking. And Brady has been making wire labeling systems for at least 45 years.
Of course -- even nicer -- but it requires a factory to lay the cables into harnesses properly -- is a thermal printer which will spool the wire through labeling it every few inches -- and the label will stay with the wire there. You start with design software to uniquely identify each wire by a number or number-letter combination, and then produce the wire to the right length (plus service loop spare length), lay it out on a cable harness pin board, lace it properly, and then lift it up and plop it down in the project. (Oh yes -- you probably want to crimp terminals on the ends of the wires at just the right length to leave a service loop before you drop it in place.) (This is how the wiring harnesses in flight simulators (and presumably the aircraft which were being simulated) were done -- projects in question were for the Navy at that time. And the software was run on a Mainframe at that time, while the simulators were controlled by one or two minicomputers. No micros in those days. :-)
He'll need a port for the netcam he'll mount on the machine for remote monitoring of the long slow jobs.
cartridges fit either
P-Touch labels are available in an industrial strength adhesive version which are good for labeling modules, servo drives, etc. For wires just put the P-Touch label on and cover with clear heat shrink tubing. Some P-Touch models like the 1500PC I have also have the nice feature of printing graphics, which can allow you to do machine related icons.
P-Touch is the line of label printers made by Brother. The PT-1500PC is the one I have, it's PC only (USB, no keyboard), and it will print any graphics you want. Nice for putting tool pictures on your tool chest drawer labels for faster ID, and other specialty icons.
Years ago I used 3M write on labels. I covered them with clear heat shrink. It worked pretty well. I *hate* wire labels you can not read. The numbers are gone but the problem is right there in your face needing a repair.
-- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller
I would recommend that you use 24 volts for the estop line and going to the microswitches. The first time you get a shock after touching a microswitch with 110 vac on it you will know the reason why. Every machine I worked on uses 24 volts on all the control input wiring.
One could not be a successful Leftwinger without realizing that, in contrast to the popular conception supported by newspapers and mothers of Leftwingers, a goodly number of Leftwingers are not only narrow-minded and dull, but also just stupid. Gunner Asch