Industrial Switchboards

[conducteur]

I always have to lay al the wires and connect them on the projects that we make in the model-train-club. I try to do that as good as i can, but i know that i still can learn a lot.

Last week, we visited "Ninix Technologies" with the school (we learn LabVIEW, and they use that a lot, so they gave us a demonstration what you can do with labview). It's a local company that makes machines for industrial process automation....
http://ninix-tech.com/

Of course, every machine that they build has it's own switchboard (or more than one). What I noticed was that they're always so nice and tidy....


So my question is: how do they start making such a switchboard? How do they start the layout, is there a fixed "layout" structure for things like that? To they use flexible litze wires, or not? Is there a minimal wire gauge? When do they use those special clamps?  (http://www.conrad.be/medias/global/ce/7000_7999/7400/7440/7447/744725_LB_00_FB.EPS_1000.jpg)...
I think if i understand this process better, I can achieve better results on our train layout, because sometimes i have a similar situation: many cables that comes together to one point, where a bunch of electronic modules are placed....

[Christopher]

Those are din rail terminal blocks

Din rail is a standard rail which mounts in many boxes.

Loads of components, relays breakers etc all fit on this standard rail allowing for easy changes and quick design

Don't ask me/us engineers how to make it neat. That's the job of a panel wireman.  I just hand them a schematic and let them figure that out

[tautech]

Cabinetised?
There's also the Pheonix range of Din rail modules:
https://www.phoenixcontact.com/assets/interactive_ed/global/modules/0001074/index.html#/0

[128er]

So my question is: how do they start making such a switchboard? How do they start the layout, is there a fixed "layout" structure for things like that?

When you manufacture complex machines, you most likely have some sort of advanced CAD system, like EPLAN or WSCAD. It starts with the schematic. And as in electronics CAD packages you can do the layout of the switchboard, by placing the components on the mounting plate in the CAD program. You try to arrange the devices in function groups. For example, in a first step you seperate the control circuit from the load circuit. You do not place the 10 kW variable frequency drive next to your PLC with analog modules. Function groups are also good to get a better orientation in a switching cabinet. And to keep wiring as short as possible.

When do they use those special clamps?  (http://www.conrad.be/medias/global/ce/7000_7999/7400/7440/7447/744725_LB_00_FB.EPS_1000.jpg)...

These terminal blocks are used to interface the cabinet with the field devices. Nowadays you often see cage clamps instead of this screw connections. There are endless types of different terminal blocks on the market.

You can look here for example: https://www.phoenixcontact.com/

To they use flexible litze wires, or not? Is there a minimal wire gauge?

Usualy you use 0,5 mm² H05V-K as an absolute minimum cross section. 0,5 - 1 mm² is normal for digital PLC inputs. Because they are not carrying any significant amount of current.  In realy old machines you often see rigid wires in the switching board.

What I noticed was that they're always so nice and tidy....

The nice and tidy look also needs a little bit of craftsmanship. But it's also a thing of choosing the right tool for the job. How do you guide your wires under your modeltrain assemblies?

[128er]

Don't ask me/us engineers how to make it neat. That's the job of a panel wireman.  I just hand them a schematic and let them figure that out

Tha'ts also the usual way in my company. I get the schematic and do the layout by myself. Considering some basic techniques. Like placing devices with huge power dissipation in the top of cabinets, so that the heat does not rise over all other components.

[conducteur]

Any other tips for my "work"?

[128er]

Any other tips for my "work"?

Is your goal only nice and tidy?

As I said, you need practice to make it look nice. You could use slotted wire duct. Or some kind of cable tie mounts to guide your wires. Look through the catalogs of industrial suppliers to get ideas. Phoenix Contact, Weidmüller,  Rittal, OBO Bettermann, Siemens.

Picture from miniature wonderland in Hamburg:

[DenzilPenberthy]

When drawing your schematic number each of the individual wires or nodes.  Most electrical CAD packages will do this automatically. Also keep track of what size and colour of wire each one is. e.g. by marking on the schematic or in a separate table. Make sure that terminal blocks are numbered and terminal numbers are marked on components e.g relays, PLCs etc..

e.g.


http://static-dc.autodesk.net/content/dam/autodesk/www/products/autodesk-autocad-electrical/images/screenshots/automatic-wire-numbering-large-1152x648.jpg


Then lay out your components (typically all DIN rail mounted) in a rough scheme of where you want them positioned. Get a big sheet of aluminium that fits in the back of your cabinet and fix all of your DIN rails and slotted trunking to it. Mount all of your DIN rail components and anything else can screw straight to the aluminium sheet. Label all of your components to match the schematic. e.g. Write RL1, RL2, RL3 etc on the relays and X1, X2, X3 on all of the terminal blocks. The DIN rail terminal blocks come will little numbered inserts that just click into place.

Next, take your schematic and a highlighter pen and as you fit each wire mark it off on the schematic by tracing over it with the highlighter. when it's all coloured in you've finished. Route the wires through the slotted trunking so the pop out neatly by their terminal. It will look beautiful once the covers are fitted!

For control panels like this most people use 'tri-rated' flexible wire. It has very hard wearing insulation that is sufficient to meet European, American and (I think) Canadian standards so should be good enough for anywhere. At each termination fit some slide on wire numbers to match the numbers on your schematic and fit a bootlace ferrule. It is time consuming but about 1000% less time consuming than having to work on a panel with unmarked wires and stranded ends stuffed into terminals. The terminations will look like this:

and the finished panel will look something like this:

Above all be super methodical and super strict about keeping the schematic updated with any physical changes you make.!

[SeanB]

In the automotive world they use Catia ( and if you think Altium is expensive, wait till you ask the price per seat, and the yearly maintenance price) to develop the 3D models of the wiring, then literally measure each wire and get them to the right length in 3D, then make it on a massive wooden board with a jig.

On industrial panels you typically start with a few rolls of panel wire, either solid or stranded ( as an apprentice I had to use solid wire, so as to get all those lines straight, all turns 90 degrees and all the terminations the same strip length so as to have 1-2mm of bare wire outside the clamp surface. No cable ties, you used lacing twine and a needle to lace up the bundles with the right knots, at the right spacing, and with the lay all identical) and typically work your way through the netlist, running each wire individually and placing it in the trunking and routing each to the point, then feeding out, marking the end and then cutting and terminating the wire. Solid wire you typically used direct under the terminal cage, but stranded you would use a bootlace ferrule to hold those strands together so they do not short out to adjacent terminals. Up to 4 wires per terminal in most cases, otherwise you have a commoning point somewhere and bring them all back to it.

On aircraft you then took the wire out, went to the hot marker and put an identifier number on each wire with it, embossing the number of the wire and it's general part number into the insulation so you can identify it in the loom later. When all have been done you sleeved it with some woven plastic or metal mesh, cut to length and with the end clean and fused in the case of plastic or with a pigtail for the metal one, and then finished off the ends with a sleeve cover and some securing lace or wire to keep it from unravelling. Then put the entire loom in place and clamp with rubber lined clamps, put the plugs on and connect. When you see in an aircraft that massive bundle of cable, every wire in there has a number on it along the length.

[conducteur]

Thanks a lot for the useful tips! I need to invest in a propper crimp tool....