Aisle split table and TIU question

Not hard to get to 45ft cable lengths.  I have a remote section of the layout connected by an Atlas double track bridge, (installed across a doorway, when I run).  From the power supply 8ft up the wall, 8ft down the wall, at the remote section. add 15 ft across the ceiling, may be 20, routed neatly.  Add a minimum of 5ft at each end for termination. I've had no problem with either TMCC or DCS.  

Remote section wiring.  Black and white coiled wires are two track circuits.  Brown multi conductor thermostat wire is switch and other control.

Control power end of wires. 

Track circuits, control panel ends.  14 ga solid THHN wire. 

 

 

For 45 feet, I'd consider #12 wire.  For that distance, assuming 7.5A of load, you'll already drop more than a volt.  That doesn't consider the additional voltage drops for distribution after you wire to the tracks.

The AIU shouldn't be a problem if you use heavier wire for the power.  The issue with the distance will be power drop of the 12V supply, but using heavier wire (#22 or larger) for the power and ground will alleviate that issue.

Note that for #14 wire, the drop is 1.7 volts to the distribution point.

When you have a question like this that probably has been asked by many others already, try doing a search.

This popped up as the first reply when I searched.

https://ogrforum.com/topic/aiu-cable-length

I have long runs of #14 stranded wire pairs running and it works well. There have been posts that actually suggest using extra wire on very short runs to equalize the signal and responses from the engines. I have short runs without any issues mixed with my long runs. I believe every layout presents different issues.

 When I first read all the rules, I considered centering my single TIU (at the time) in the ceiling and run equal wires out. I tested with it at my power panel and never found  any harm in mixed wires. My biggest problem was buying many engines and leaving them on powered track. That eventually dragged the signal down enough to cause issues. I had to install switches to kill the engine sidings so they all weren't on powered track. I later added extra TIU channels with the switches to keep things running smoothly.

Marty's answer for the AIU is what prompts me to suggest heavier power wiring on the AIU cable runs.

https://ogrforum.com/...75#71678964505440275

You can also add an aux 12VDC power supply to the distant AIU, though I prefer having all the power from one source, hence the recommendation for larger wires for the power pins.

I had to do something similar. My Power supply and TIU are a short distance from my yard area. But a long distance traveling around a U. It would have been about a 60 ft. run. I ran wires off my power supply under the benchwork of the main layout. Up a Lally column. Across a carrier beam then down to the yard to a second TIU. I needed the second TIU anyways. I figured the slight voltage drop going to the TIU was better than a long run to a distribution point. It was around a 30 ft. run off the power supply.

Thanks all. (I did a search but I concentrated on second TIU, so apologies for replication). The extra voltage drop between the 14ga and 12ga was more than I thought it would be, so I'll be making a trip to the hardware store tomorrow.

Good question, Scott!  I always appreciate others' questions.  I have had good success with the search engine Hoopla provides the Forum, but sometimes I don't think of the right words to search just as with any search engine!  It is good thinking to consider this issue before wiring the second section and find out you used too small wire.

ScottV posted:

Thanks all. (I did a search but I concentrated on second TIU, so apologies for replication). The extra voltage drop between the 14ga and 12ga was more than I thought it would be, so I'll be making a trip to the hardware store tomorrow.

So we're talking a difference of .63 of a volt? (if I'm reading correctly?)

Correct Joe, but if you use electrocouplers, it's not uncommon for them to demand nearly full track voltage for proper operation.  Also, those numbers go up if you assume a different current draw, I used 7.5A as that's a practical limit for normal running.

To answer part of your question directly - yes, you can use each handle of the Z4K separately to power each half of the layout with one handle going to Fixed 1 and out to a distribution panel and the other handle to Fixed 2 and out to a second distribution panel. The 45 ft. length, in itself, should not create a signal issue. I would go with the 12 gauge if you are starting from scratch. If you had a lot of extra 14 gauge laying around, I would try that first. As far as going up and over two doors, have you considered pulling up that section of carpet and running the wiring underneath or even on top of the carpet under a vinyl/rubber/plastic protector ?

gunrunnerjohn posted:

Correct Joe, but if you use electrocouplers, it's not uncommon for them to demand nearly full track voltage for proper operation.  Also, those numbers go up if you assume a different current draw, I used 7.5A as that's a practical limit for normal running.

Well he said he has the Z4000, so he can turn the handle up a touch!

Given the fact that TMCC/Legacy doesn't like to see more than 19 VAC maximum, that's an option that I'm not sure I'd endorse.   If you have a light load on that track, you could have 20-21 volts and exceed the stated maximums.  I don't know that it'll cook the board, but I tend to stick with the maximum recommended voltage for my Lionel stuff.

Richie, that was my first thought.  The under and over carpet runs were both "vetoed". 

 

John - it's been a bit since i had my Lionel engines out....thank you for the reminder on the 19V !! 

The only other option would be to fish the wire through the wall. If that's not possible, I would probably use plastic conduit (rather than clamps or clips) to secure and help hide the wire running along the walls and door frames.

FWIW, I run 10, 12 &14 ga wires for ac and dc track power and 110 volt power supply through wire molding around a door frame and 110 in conduit  around the layout.

I also use hollow flexible feather edge  plastic transitions  strips for crossing aisles.  Available HD & Lowe's.

Another way to carry power across a lift out is to use through wiring with dependable Anderson Power Pole connectors on the bottom of a lift out bridge.

Power poles permit adding as many wires as needed cresting a multi pole genderless  plug which attach to themselves in width, height or both.

gunrunnerjohn posted:

Given the fact that TMCC/Legacy doesn't like to see more than 19 VAC maximum, that's an option that I'm not sure I'd endorse.   If you have a light load on that track, you could have 20-21 volts and exceed the stated maximums.  I don't know that it'll cook the board, but I tend to stick with the maximum recommended voltage for my Lionel stuff.

Yes, I totally agree. I don't go above 18 volts when I run my TMCC stuff. This is all just my opinion.

I would suggest testing at the track area to see exactly what the voltage is. (As you know, GRJ ) Some times with a long wire drop and using 14 gauge wire, you may put 18 volts out and the engine doesn't see that at the boards.

 I thought he was using the handle #2 on the Z4000 to go to this section. So I was thinking he could turn the voltage up until it read 18 volts at that area of the rails to make up for any voltage loss using #14 wire. The Z4000 will go well above 18 volts. So you have to be careful of how high you set the handles for TMCC/Legacy equipment anyways. For that reason specifically, I would test the actual voltage. That's good practice for anyone to show any areas on the layout that may have power distribution problems. In command mode, these toys won't show the areas as well as if you test in conventional with a decent draw.

 If you starve equipment of proper voltage (surely by accident on bad areas ), the amp draw will go up, right?

I just had some issues with certain wire types of #12 carrying signal. I found that #14 worked the best all around for good power and signal. Your mileage may vary. You could try #6 for all I care, but it would just be a waste to me. We aren't drawing that kind of power.

I have always  worked under the assumption in calculating wire size and drop that I take in consideration both legs of the supply, out and back.   That is how I selected the use of 10, 12 or 14 ga star runs.  My longest runs are 100' one way.

Is this a floating table? There has to be wall on one edge...locate the power and control wiring there- opposite of the doors

Also, consider using oversized residential exterior plastic  J molding for easy to service "open conduit" of sorts.  The large size is typically not carried in big box stores.  Available at roofing and siding supply houses in 12' lengths.

The pliable  J molding is captured by the benchwork frame in my  off scene staging room.  This molding is easy to flex open for servicing your wires.  I use it also for a computer cable run.

Just run it along the outside bottom edge.  Relieve yourself of crawling underneath.

I am planning on using the 2nd handle of the Z4000 for the other table, so I can adjust it for the track on that table to receive ~18v.

Carl - 2 tables, both wall hugging, with an aisle heading diagonally through it from a super-wide entrance at one corner to 2 doors located at the opposite corner.

 

 

Scott, yes I can picture your layout room better now.  Working around doors that need to allow for traffic flow is a major concern for my layout room too.

Tom Tee posted:

Another way to carry power across a lift out is to use through wiring with dependable Anderson Power Pole connectors on the bottom of a lift out bridge.

Power poles permit adding as many wires as needed cresting a multi pole genderless  plug which attach to themselves in width, height or both.

https://www.towerhobbies.com/c...01p?I=LXD176&P=7

Richie - Thanks for posting the link for the power posts!

No problem Scott - we used them for battery connectors in r/c racing many years ago. The plastic holders slide together to form a pair (a small drop of CA glue helps, too) and the wire(s) get soldered to the metal piece and then inserted into each holder - when they're in properly you should hear or feel a "snap". Then they mate with their counterpart. They are bulletproof and would be great if you only plan on taking out the lift out infrequently. You may be able to get them in smaller quantities at Tower Hobbies or at a better price somewhere else - check around.

I had a similar problem.  In the middle of the room, I went UP to the ceiling, OVER about 8 feet and then DOWN the other side for a total run of about 25 feet.  It has been working about ten years now without any problem.  This was for a switch machine power supply and I used 14 gauge wire.  The  voltage at the source is about 2.6 volts.  The drop is minimal.  I don't remember the actual voltage drop.  I did not disguise it.  It still looks like wires hanging from the ceiling.  I guess you could put a model kite on it.

Just a thought.

Ed

Ed Kelly posted:

I had a similar problem.  In the middle of the room, I went UP to the ceiling, OVER about 8 feet and then DOWN the other side for a total run of about 25 feet.  It has been working about ten years now without any problem.  This was for a switch machine power supply and I used 14 gauge wire.  The  voltage at the source is about 2.6 volts.  The drop is minimal.  I don't remember the actual voltage drop.  I did not disguise it.  It still looks like wires hanging from the ceiling.  I guess you could put a model kite on it.

A switch machine and a full train with lighted cars, Pulmore motor, etc. are two QUITE different things!  For switch machines, I run #22 or #24 wire, they work fine, even at long distances.

Gunner...

I was providing a technique not directions on how to bake a cake.  14 gauge wire provides the lowest practical voltage loss.  Also, up, over and down as opposed to over or under the carpet.

Think, man, think.

Ed

 

I was thinking, you gave a specific example and I suggested that isn't a typical situation.  We've already discussed why it's possible that #14 wire going more than 45 feet could be marginal, complete with real numbers.  I doubt there's any argument that you can run a switch machine, or a dozen of them, using #14 wire.  I'm at a loss as to what technique you refer to, a dangling wire from the ceiling probably isn't what is desired here.

Think, man, think.

I am tired of the sharpshooting here.  I offered an alternative to under the carpet and what do I get,  nonsense. 

Bye.

 

 

Sharpshooting?  Hardly.  If you leave a snarky answer, don't be surprised if you get an in-kind response.