Electrical Wiring…Arrghhh!

Let me start by stating that I don’t consider myself electrically inept.  In fact, I have formal training in the electronics field.  But sometimes you can let a project get the best of you.

Let me back up a bit.  The Louisiana Central will have four staging areas.  On the west end of the layout, there will be a hidden staging track for an Illinois Central train and another for a Texas and Pacific train.  Over on the east side, there will be four staging tracks, two for the Illinois Central and two for the Louisiana Central.  Since the tracks will be hidden from normal viewing angles, I decided to install an optical detection system which will light up LED indicators on panels showing when a train is nearing the end of a track, and also the clearance point at the entrance to the track.  Simple enough.  In researching the task, I found a fellow up in Canada who offers nice, tidy, little circuit boards that will fill the bill perfectly.  All one has to do is install the phototransistors (hereinafter referred to as P.T.s), the infrared LED light sources, and the LED panel indicators.  Bring all the wiring from these devices to the little circuit boards, hook up a wall-wart power supply, and you’re done.

I have procrastinated for months starting this installation.  It wasn’t because I was intimidated by the wiring, rather it was because I just didn’t feel up to the tedium of the task…running all the wire, making the hundreds of wiring connections, fabricating mounting brackets for the devices, making the panels, etc.  The time to do the task is while the staging track is visible and easily accessible.  I don’t want to install any sub-road in front of the staging until that is complete.  Well, that time has come.  Further progress cannot be made at Monterey (the west end of the line) or to the LC mainline, or the Spencer logging operation between Whitcomb and Maynard until this work is done.  So I resolved myself to installing the system at Monterey this past weekend.

Things started out well enough.  I bored holes at the appropriate locations in the track to receive the P.T.s.  They slipped right in and held firm just by the friction in the hole…great!  I planned to use a recycled 25 pair telephone cable (donated by a friend), so I unrolled the cable and stretched it out along the top of the joists adjacent to the staging tracks.  The only way I could think of to splice into the cable at various points was to go ahead and pull open the outer jacket for much of the length of the cable, a task made easy by the little ripping string provided within the cable bundle.  I figured I would wrap electrical tape around the cable every 8 inches or so to keep things together.  So far, so good.

This is where things started going south.  I decided to use the black/white striped wire along with the white/black striped wire in parallel as the common negative wire (using two wires for less resistance and for a margin of “backup safety”).  I selected those and one other cable and soldered them to the pigtail leads from the first P.T.  To insulate the joint I had planned to use small wire nuts which I thought were made for this light gauge wire.  They didn’t work…wouldn’t bite onto the wire.  So I pulled out my Scotch 33+ electrical tape and proceeded to wrap it around the wire nut and wire to hold it all together.  After using what seemed like a yard of tape, I had the joint secure and insulated.  It looked like something from a Chevy Chase movie.  I did the next couple P.T.s like this and finally decided that this was ridiculous.  So I went searching and found an old stash of heat shrink tubing.  I clipped off an inch, slipped it on my next joint and shrunk it down.  Finally, a decent looking insulated joint!

As I progressed, I found that removing about a foot of the outer jacket at the spot where I wanted to make a connection, then forming a loop in the cable, allowed me to easily grab a wire, clip it and solder it to the P.T. pigtail.  When I got to the 7th P.T. down, I noticed my next mistake.  Despite writing all the wire colors down as I used them, out of the 50 wires available to me, I had managed to use the same color twice for two P.T.s.  Rats!  Since I had severed the twice used cable at the 7th connection, I had to go back to the 1st (where the color had initially been used) and select another wire to re-do that connection.  Plus, the pigtail was now a tad too short, so I had to make an extension for it to reach the bundle.

OK, now I have all the P.T.s connected and I have to anchor the cable down.  I performed that task without incident.  But the joy wasn’t to last long.  As I began inserting the P.T.s into their respective holes, when I got down to number 7, I found that the leads weren’t near long enough for it to reach it’s hole.  While connecting the P.T.s the entire cable had shifted on me without my knowledge since I hadn’t anchored it at the beginning.  Arrghhh!  About then, two other realizations hit me.  One, I had attached the cable to the top of the joists.  But now I realized that once the sub-roadbed for the Monterey yard was installed, those cable mounts would be forever inaccessible.  This means that the cable would automatically be in the way of every future thing that would have to be done under the layout and there would be no way to move it.  Realization number two: I had forgotten to run the cable to the indicator panel location.  Aw, geez!  I put the tools down, killed the lights and retired to the house for the night.

Sunday morning I mulled over the entire fiasco while consuming a couple cups of coffee.  I analyzed all that had gone wrong, what was needed to correct the mistakes and what course of action I should take.  I finally decided that the only reasonable thing to do to fix everything was to simply tear out what I had done and start over from scratch.  Painful, yes.  But not nearly as painful as the potential headaches I would face later if I simply tried to patch what I’d already done.  So armed with the knowledge gained, and a renewed hope of success, I headed back out there later that afternoon (after watching the sweet Saints victory over the Texans).

I started where I should have in the beginning…at the indicator panel, then routed the cable over to the back by the staging tracks.  This time I routed the cable below the joists and supported it by the hangers (simple EMT conduit clamps) screwed to the bottom of each joist (screwed is key to easy shifting or removal of the clamp later if need be).  I taped the opened outer jack at each hanger and also between hangers and that has worked nicely to keep things orderly.  I stopped when I reached the first P.T. location; this is where I’ll pick-up at the next work session.  I plan to attach new longer leads to the P.T.s and simply coil the excess length so I have it if I need it later.  The loops I make in the cable will be directly at joists so they may be supported properly rather than drooping down between the joists as they were initially.  And the cable will be anchored as I go so it will stay in place.

I feel much more confident in this latest approach, as I’m trying to think this through much more thoroughly and apply what I’ve learned from the mistakes I’ve already made.

But just in case, wish me luck!

-Jack

2 thoughts on “Electrical Wiring…Arrghhh!

  1. This was also a good lesson in building a wiring harness. The more time you spend on it above the layout at the workbench, the less time you spend under the layout.

    Still, it this is a major feature of your layout and really important. Good going!

  2. Not me Jack, NCE has a thing calle BD 20 short 6 inch piece of track engine touches it, BD 20 tell AIU 01 Terminal xx someone their and lights the light. Not into reinventing the wheel. Wire each one as you go and no need for wiring harness. AIU has 14 terminals so could handle both ends of staging 7 track yard. Or simple light detector would do same thing.

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