Wiring Inside a Control Panel

I have a question about wire gauge.
I’m using 18 ga wire for runs to my Atlas UTT switch machines on my 4x8 HO layout. I’ve also used terminal blocks to connect my feeders to 18 ga wire that run back to my cabs.
However, I’m about to start working on a control panel that will use a mess of miniature toggles to control the turnouts and switch between blocks. None of the terminals on these switches can accept 18 ga wire. If I terminate the long runs of wire at terminal blocks behind the control panel, what should I use to connect between the terminal blocks and the switches? I’m hoping that someone will suggest Cat 5 network cable, since I’ve got a mess of it on hand. Each conductor is solid 24 ga (I believe) and is helpfully already color coded. The distance inside the panel from the switch to the block will probably be no more than a foot or so.
Also, I’m using a thin sheet of aluminum for the panel. Where should I put the the terminating terminal blocks? My layout has 6 blocks, 12 turnouts and 6 turntable stall tracks, and the panel will have indicator LEDs for the turnouts, so there’ll be plenty of wires terminating back there. I’m planning to build a frame for the panel and hinge it to the vertical side of the layout table.
I’ve seen plenty of pictures of peoples control panels, but not too many of how they organize the guts inside. Any suggestions would be very welcomed!
Thanks,
David

Hi David,

If all you are running is signal power to turnouts on a 4’x8’ layout, then your Cat5 cable should be fine inside the contol panel. Place your terminal block(s) on the edge frame of the panel (what, you don’t have a frame?) or attach it directly to the back of the panel with epoxy or some other adhesive.

I found that for multiple wires like this, the use of the DB-9 or DB-25 computer connections made connection / disconnection of the panel quick, easy, and sure. While I don’t recommend using solid wire with these connections, it does make the job of making and breaking the connections a lot easier. Terminal blocks are great inside the panel, but for connecting the panel to the railroad, consider using the computer connectors. You can get them at Radio Shack.

Mark C.

For VERY short distances you can probably get awa with the Cat5 wire. But I wouldn;t do the usual one wire from the terminal strip to all switches common wire thing, if you then run more than 1 train you will have all the power for them going through just one 24 gauge wire.
I would prefer to use something a little larger, such as a #20 wire. That should fit in the switch terminals, even for small toggles. It doesn;t have to be all color coded - just tag each wire with a wire tag or use pieces of masking tape, and write on some designation that you cna reference in a notebook - ALWAYS keep a notebook with detailed information on how you wired it, you will thank yourself later when you have to go back and troubleshoot, or you want to expand.
A good example of cab control panel wiring is in the old Kalmbach book HO Railroad the Grows. There’s all some in one of the other books I have that is a compilation of 4 track plans from MR from the 60’s and early 70’s. The basic idea is to wire all the toggles at the bench before installing them in the panel. Each one is wired to a terminal strip, all wired identically. You then install the switches and screw down the terminal strips. Run some jumpers between the common terminals on the teminal strips, and connect your block wires to the appropriate strip and you’re done.

–Randy

dehct,

You don’t need to thread the wire through the terminal on the back of the switches. Just tin the lead on the switch and tin the end of the wire, then hold the wire parallel and adjacent to the terminal of the switch and heat it 'till the solder melts, then remove the heat and let the connection cool. It will be plenty strong, and much easier to change if you ever need to.

You really should use a little larger wire, preferably stranded, but the solid wire will work OK for short distances, even if the rest of the wire is larger. How large is the motor winding wire? It carries all of the current in the circuit when only one motor is running.

Mark C.

something else that may help you with the control panel is set the control panel board to the benchwork on hinges…that way you can lower the control panel board down, wire to the back of the toggle switches, and then move it back into position… you can secure it in the upright position to the bench work with a couple of screws…I hold my wire bundles together with plastic wire ties to make it look neat instead of a massive nest of wire spagetti…Chuck

Thanks for all the suggestions. I guess if I keep my 24 ga wires to 8-12 inches, only running from the switches to the terminal blocks, I’ll be ok.
And yes, cwclark and mcouvillion, I was planning to mount the aluminum panel on a wooden frame, and then hinge it so I’ll have easy access.

  • David