Powering a large layout

I have a 20' X 60' layout with three mainlines.

That is a large layout.

I was instructed to wire it up as one big loop and that's the way it is now.  There are no block sections in it.

That was not good advice.

The best way to make a large layout run well with strong DCS signals is to turn it into several smaller layouts.  Creating blocks and using multiple TIUs allow you to do that.

If I add another TIU and another Z4000 will that allow me to run my 10 big trains at one time. 1 big boy and then 9 consist trains two that are passenger trains. All are MTH PS2 of PS 3.

Passenger trains with incandescent lights are power hungry.  Three Z-4000s may not have enough power to run your 10 trains at the same time.  Have you calculated how much power each train uses and then added them up to see how many amps they draw? 

If you want to DIY I highly recommend getting Barry's book and look at information on electrical blocks, star wiring and how many track sections to have in each block.  The DCS forum is a great place to ask follow up questions.

Thanks. Where do I get Barrys book?

Here you go.

http://mthtrains.com/content/60-1279

You can get it as an e-book or soft cover from MTH.

http://mthtrains.com/content/60-1279

Can someone explain why DCS has this issue on larger layouts?

DCS sends digital signals through a layout's wiring to the track.  Each wiring and track joint creates a place where the signal can get degraded or reflected.  Running a big loop as one block can create an echo chamber for the signals and the locomotives have a hard time hearing the message through all the echoes. By wiring a layout in blocks with a max of about 10 track section you limit or eliminate the echoes and get 10s for signal strength.

He needs to wire his layout like clem did.  clem has one loop ~350 feet of track if I remember.  The loop is divided into 4 power blocks.  He uses a Lionel PH-180 brick and a TIU channel for each power block.  He does need to up his wire size, he has voltage differences when crossing blocks with multiple engines leading a train.  When the club was over we had no trouble running 6 trains at once all night.  I do not know how many power feeds he has in each block.  The center pins need to be removed between each feed, only one feed for a section of track(~10 joints or 11 pieces of track).  Just adding more power doesn't do any good unless you do it right.

Dan

Nothing is wrong with DCS.  The average guy does not run that many trains at the same time.  On Gargraves track Tim, do you have the outside rails connected?  I am a fan of how you wired but have one more question.  How far apart are your track connections?  If they are close, that will be an issue.

I have 10 gauge wire running in a circle of the layout and the transformers in the middle. My drops are every 6' or less. I have lots of sidings and a 10 track switch yard. If I block it up I only have to cut the center rail to make my blocks I would guess. all of my outside rails are connected. How many TIUs should I use?

How many feet of track in a loop and how many trains do you run on a loop?  The advantage of using power blocks you can have 4 x 10 amps on a loop but each block will only have 10 amps.  The trains should be spread out around the loop. You could do some serious welding with 40 amps in one place.  You will need a TIU channel for each power block.

Dan

210 feet on each of the three loops and we want to run 3 consist trains on each loop. So two double motor powered units on each train in that loop.

Your drops are way too close.  Every 12-15 feet will give you good signal.  A good rule is one drop per block if you go with the blocks.

So if I go with 8 blocks and 2 TIUs I will have 100 feet of track on each block with the drops at 12 feet correct?

One important thing that hasn't been mentioned is that you need to do a "star-pattern" or hub-and-spoke wiring system. Each block gets its own pair of feeds direct from the TIU. Just dividing the layout into blocks will not help that much if you are using a common bus for power. 

Our museum layout is quite large, but only the longest loop requires more than one TIU channel. The rest have one channel apiece. For most layouts, one channel per loop is fine, as long as the blocks are isolated and the wiring is direct to each block.

Also, if your TIU's are not the latest (Rev L), you may need to add light bulbs or diode packs in parallel to filter the signal. This is a known peculiarity of DCS, which MTH fixed in the most recent version. We had these on all of our feed wires until we changed to Rev L TIU's. 

All of the above is covered in Barry's book, except maybe the part about Rev L not needing the light bulbs. 

I run my layout with one TIU using what we used to call "star" or "homerun" wiring.  That is the track is cut into blocks and each block has a power and common wire back to a collection terminal point and then to the TIU.  This is a photo of all the drop wires arriving at the collection block for just my #2 mainline and all the yard tracks.  I have another one like it for my #1 mainline.  All this off one TIU.  I use an old ZW for power and the layout fills half my basement.  Runs great.  Switches are run off a separate transformer.

.....

Dennis

I'm going from my own experience wiring a large super mode (4 tiu) single track layout. (about 7 scale miles of track) Power is 8 postwar ZWs, 10 amp fast blow glass fuses  between ZW handle and tiu input.  Blocks are about 30 feet long but  there are exceptions ..Shop area  with turntable uses one tiu channel.   Tiu must be in range of remote so all the tiu have had the antennae modification.  We use terminal blocks with a  magic bulb on each one.  The tiu are spread out  at 4 locations on the layout.

The layout runs really well but it was not that easy to get up and running. we wired one  block at a time testing the track signal as other blocks were added,eventually  a new tiu channel and then another tiu  etc.  we now have 4 tiu.

My suggestion would be to test as you rewire.

 I agree with Marty, tooo many short blocks can degrade the dcs signal in short order.

We also dropped outside rail feeders to both outside rails.

Hope this helps.. if you hook up one block and get a perfect dcs signal add another.....

Use heavy wire.  Stay clear of 16 ga on a layout your size.

Yup, Marty.  That's 14 gauge wire in my photo above.

....

Dennis

Gentlemen,

   I agree with Marty F 100% use the heavy wire and break things down into blocks using the 12 track discipline and your layout will run with all 10's.  If you purchase another Z4K and add it to your power station you should have plenty of power once you break things down into blocks.  Power your switches from their own transformer,

I used an old ZW and Daisy Chained my switches, it works great.  If you are using old Lionel Switches & Controllers, replace the bulbs in both with LED's.

Have fun with your re-set!

PCRR/Dave

Someone mentioned a TIU antenna upgrade. Is there an external antenna you can buy?

Nope! you have to drill a hole in the tiu and stick the antenna up through vertically. It helps but it's also very fragile. Having the tiu  on or above the table also helps especially with large layouts where range might be  60 or 70 feet.

Marty

 with all of the help from this post I think I have a plan in place just need help exicuting it. We have 3 Z4000 transformers a two TIU's. We have ordered one more TIU and we are sending the others to our repair guy to update them with the newest version. If I use all 4 channels of each TIU I could have 12 blocks. 10 of those blocks I can use on my main line loops and the other two on yard tracks and roundhouse area. So on the 3 main line tracks that circle the layout I would have 10 block areas do you think that is a good idea? 

Tim,

   I was trying to wait for Marty but I will add my advise also.  It's not just the blocks, use the 12 track join disciple, as you build your blocks, the less track joins you have the better the signal.  I used many 36" pieces of FasTrack when building my multi level office/game room layout, it all ran with 10's because I used this discipline with magic lights, and tested my track as I built. 

PCRR/Dave

Dennis,

When creating your blocks are you cutting the "hot" center rail and both outside "common" rails?  This would fully isolate the block.  Your explanation and excellent terminal strip wiring seem to say that.

Do you have toggle switches to "power off/on" the blocks?

If I wanted to include toggle switches to "power off" blocks would they be placed after the terminal strips?  Assuming the TIU is upstream between the transformer and the terminal strips.  So the wiring sequence would be transformer to TIU, TIU to terminal strip, terminal strip to toggle switches, toggle switch to track?

Thanks!

Thanks!    

Tim,

My train room is 33-ft x 38-ft and the layout occupies most of the space. I have over 900 feet of Atlas track, 46 Atlas and 12 Ross turnouts. Each of the dual mainlines is divided into 10 districts (track blocks), and I also have 26 spurs and sidings, each of which is independently powered.

I initially had two Z4K’s, but that was not enough, so I added one ZW-L, and that was just right. Shortly afterwards I replaced the two Z4K’s with another ZW-L, and I have had absolutely no problems running the trains. The ZW-L’s appear to have much better voltage regulation, and once set at the maximum (about 18.6v), they keep that voltage level regardless of what is running. This was not my experience with the Z4K’s I had; they would drop from 21v to 16v depending on load.

I have two TIU’S, and each is powered by one of the ZW-L’s.  I located the TIU’s as closely as possible to the centers of the mainline districts, sidings and spurs they serve.

Wire gauges I use:

• Transformers (two ZW-L’s) to two TIU’s are 12 AWG, and these wire runs are 40 and 60 feet.

• TIU’s to distribution (relay*) blocks (8 blocks x 6 relays) are 14 AWG, with wire runs 15 to 20 feet.

 • Distribution (relay) blocks to Tracks (20 main districts + 28 sidings and spurs) are 16 AWG, and these wire runs are 10 to 15 feet.

Track-block lengths:

• Mainline (dual) track districts are 20 to 30 feet long.

• Sidings are 10 to 25 feet long, except one yard lead that is about 30 feet long.

• Spurs are five to 15 feet long.

* The relays allow me to shut off any district, siding or spur with a toggle switch on the main control panel. The relay control wires are  24 AWG wire, and some of these runs are over 100 feet long.

I added Legacy (just one wire to the outer rail at one point!) and I am able to runs DCS and Legacy (& TMCC) engines without any problems.

Feel free to contact me if you think I can help.

Good luck!

Alex