Wire Guage Question

Rewire.  The 16 will be great for your layout.

Let's look at this. 16 gauge would be best but the layout is already wired. Wire can be expensive. 18 gauge can usually be used for a distance of about 10 feet without any trouble. I am sure you have some runs that are longer than that but perhaps many that arn't. Do you use a star or buss wiring pattern? Or do all runs come all the way back to the transformer? If you use a star or buss pattern then the home runs should be 16 gauge. From your distribution point or your buss any runs that are less than 10 feet you could leave with 18 gauge and only replace those that are longer. If all runs are home runs back to the transformer then replace those longer than 10 feet with 16 gauge.

Al

Thanks from me Al.  That answers a question I had lingering.  My layout's been wired with 16 for years.  This winter I jumpered over some short runs with 18 just to shore it up, so to speak.  That's what I had handy and it made sense to me.  Now I know for sure that was kosher, so to speak.

Al

I run fastrack and from the track connections, I run all wires back to a 12 connection terminal block.  I run power from the DCS commander (soon to be DCS TIU) to the terminal block red and black poles.  Sorry, but I am not sure what a star pattern is.  My longer runs are around 15 to 18 ft.  Wire is expensive but I also want to do what is best for the long hual. 

HS

Before you do anything, hook up the DCS and see if it works. No sense re-wiring everything if it works OK with your 18 gauge wire.

If it ain't broke...don't fix it.  

Al,

I am going to sound ignarant, but explain the star or bus pattern?  Would I be right in saying that it involves using multiple terminal blocks to wire directly to the track then make a run from the terminal block back to the main terminal block.  Just a thought.

You are right webmaster.  That will be my first step.  I love this forum, it has help me every time I post a question.  Great people on here.

I'll throw this in because I'm here.  The bus(s) pattern is a loop of wire basically following your track pattern under the layout where you jumper up to the track.   A star pattern is one wire which terminates at a track connection and other wires 'spider' out from it and terminate at their track connections.  

Hi,  My layout is in a 10 X 20 foot attic.  I used 18 gauge or smaller wire throughout.  DCS, TMCC and Legacy run just fine.  I used star wiring per MTH's instructions.

If I'm following you right, this is a pretty good description of star pattern wiring.  

18 is theoretically a little on the light side but your layout is a little on the small side.  Rich is right, hook it up as is and run it, it may be fine the way it is.  Barry makes this point in his book, for converting existing layouts to DCS, first step is to just plug the TIU into the existing system and see how it works.  Many members here have done just that and have no issues.

My DCS  layout is wired as you described; from transformer to terminal block, pairs from the terminal block to various points on the layout.  I use the heavier wire from transformer to terminal block, and lighter wire from terminal block to track.  The terminal block is situated roughly in the center of the layout(36 ft long). Not all wire runs to the track are the same length.  

This arrangement has worked fine for the past ten years, so I don't see any reason for it not to work for you.  

Sorry but just could not resist. Did you ever watch fireworks? Do you know what a star mine is? It goes off and you have a single trail going up until it exploads and then there are streamers in all directions. THAT is a star pattern! The single trail is the home run and the explosion is a terminal block. The streamers are the track feeders.

Now a bus just travels down the street making a stop here and a stop there but never leaves the street. That is a buss pattern. The home run or feeder wires make one run around the layout droping connections to the track as they go.

There are colorful stories for everything.

Al

"If it ain't broke, don't fix it".

Voltage drop will be minimal with 18 gauge wire for the size of your layout.  It is adequate.

Just my opinion.

Mike

Another vote for trying it out the way it is.

My 14 year old 14' x 22' layout is 400 ft of tubular track wired with mostly 18 ga hot feeders and common bus returns. Blocks are switched using Atlas 4 pole A-B switches, toggles, and rotary switches.

I use all 4 channels of one Rev I3a TIU, with 18 volt bulbs on the outputs.

When I ran conventional I had a few problems with voltage drops and engines that would slow down; particularly while double heading. After switching to DCS 2 years ago these problems went away. PS-2 engines compensate for voltage losses and maintain their set speed very well.

Once you get DCS hooked up, you could run an engine with a consist around in track voltage mode, and check the readings. If you have a section or two that show more than say a 2 volt loss, you can improve them by changing to 16 ga runs, or simply doubling up the existing 18 ga run.

This keeps your rework to a minimum.

Rod

Thanks alot everyone.  I am going to hold off on rewiring for now.  I am going to hook up the DCS and see what I get.  However, I think I will change to 16 guage from the TIU to the terminal block.  I have to crimp my fastrack lock-ons they seem to want to pull looose.  Any thoughts?