Whether to Star ( Home Run ) wiring or Regular wiring using Power Feeders

I have a similar layout to yours, two loops and some sidings. Here is what I did and it has worked really well for me, good DCS signal and no DCS errors.

I used both fixed channels on my TIU, one for the inner loop and one for the outer loop. I have a separate power brick for each channel. You could probably get by with one brick for both if it is large enough too handle all the trains you want to run at one time. I isolated the two loops, isolated each loop into 4 separate blocks (maximum of 10-12 track joints per block) and then isolated all the sidings from their loops. Isolate only the center rail, not the outer rails. I powered each siding separately with a switched power drop so I could park engines and turn off the power to them. This keeps the run time hours from piling up while the engine is just sitting idle. Use a good switch rated at 10 amps or more for your sidings.

If your track has isolated outside rails (isolated from each other like Atlas or Gargraves) you need to either connect the outside rails together (the recommended method by many here on the forum) or make sure you use the same rail throughout the layout for the common rail. Separate power for switches and accessories is also recommended.

I tried to follow Barry's book for wiring as best as I could and I think this is pretty much what the book suggests. I don't think there are any contradictions, but if so I would defer to the book and follow it.

Yep!  I like RTR12s set up described above.    Using 2 tiu channels will pretty much guarantee a perfect dcs signal.( I know some are going to say." I can all that on one channel" probably true but it just so much  easier to use both channels)

You  could  even use the one power supply for each channel . just jumper fixed 1 in over to fixed 2 in..

Every tiu channel has it's own dcs signal generator . 

RTR,

Thanks for the reply and what you posted was the way I was thinking.  Back in my HO days ( 10+ years ago) wiring was DC and now AC is brand new to me. I'll be using only MTH Realtrax on the layout.

Back in the day, I hand layed my track and hand laid switches in place, and there was no power to the sidings unless the switch was thrown powering that siding.  The only sidings that will need to be isolated are the sidings under the shelves and I plan to isolate the lead track to those sidings, the Engine House Track, the Engine Service track, and the Passinger Station track, every thing else will be storage. My program track will be separate from the layout.

Ok, I'm assuming you mean a SP/ST switch on the power drops for the sidings. The only thing I'm not sure of is how to isolate the center rail.  In HO we just cut through the 1 rail, filled the gap with Ambroid glue and walah we had and isolated section. This is all new to me, meaning AC. 

Again Thanks

Kerry

Gregg,

Thanks for the reply. What I failed to mentioned to RTR12 is   That I will be using a Z1000 watt Accessory transformer brick for Switches and Accessories ,a Z1000 transformer for track power to the TIU ( Fixed 1 ) and a Z1000 Acc. Brick for ( Fixed 2 ) All transformers will of course be phased. What I haven't decided is whether to power my AIU separately or through my TIU.

I hate having to learn all over again, Lol 

Thank you again

Kerry

Well AC and 3 rail is a lot easier than DC and HO as far as track wiring goes. No polarity issues, reversing loop or switch issues to worry about. Transformer phasing with 3 rail is a very good idea though.

A SPST switch is what I used for my sidings. 10 amps should cover most anything in O gauge. On your track plan I would still consider switching all of the sidings while you are wiring things. You can always leave them powered if you want, but still have the option to turn them off if you want to park an engine sometime and keep it's clock from running.

I am not real familiar with Realtrax, but it has a metal strip under the track at each joint that connects the rails for power and common. You can bend this out of the way or put some tape or cardboard on the center between where they touch at the rail joints so they do not connect. I have not done this with Realtrax (only read about it), but others here have and maybe they will report on a better way? I don't know if the two outside rails are connected to each other with Realtrax or not, but you can easily check that with a meter.

I think you are saying you have 2 of the Z1000's? These should be used without their Z-Controllers when powering your TIU channels, just the brick only. Also the accessory output of these is only 14 volts so I would not use that to power a TIU channel. I have not tried this, but if you do have 2 of the Z1000s, I think I would use each of their main outputs for TIU channel 1 and 2 and the accessory outputs for your accessories and switches. You can probably run at least 2 trains with a single Z1000 as long as you don't have too many lighted cars. Incandescent lighting would use more power and LED would use a lot less so the quantity will vary depending on type of lighting. 

If you do use 2 TIU channels I would also seriously consider powering your TIU through it's Aux power port with a Z500 or a wall wart. The DCS book describes what you need for power for the TIU Aux port, I don't recall the rating for it without looking. I have a Z500 from an MTh set that I am using for TIU power.

Adding a TVS diode to your terminal block feeds is also a good idea and will help prevent voltage spikes to your electronic engines. There are many threads here on the forum about TVS protection that explain it much better than I can. If you are interested in using them, a 1.5KE36CA is a good choice and has been recommended here by many forum members. Here is one from Digi-Key 1.5KE36CALFCT-ND. Digi-Key has very reasonable USPS shipping for small orders.

Kerry,

What I haven't decided is whether to power my AIU separately or through my TIU.

There's no decision to make. The AIUs always get power for themselves via their connection too the TIU.

RTR12,

Adding a TVS diode to your terminal block feeds is also a good idea and will help prevent voltage spikes to your electronic engines

That's unnecessary. There's a TVS built-into each TIU channel.

This and a whole lot more is all in “The DCS Companion 3rd Edition!" This book is available from many fine OGR advertisers and forum sponsors, or as an eBook or a printed book at OGR’s web store!

RTR12,

Thanks for your info.

To clarify, I am planning to use a Z1000 Transformer/Controller to power the TIU Channel 1 through its 18volt output and a Z500 or Z1000 brick for channel 2 and switches and accessories through the bricks 14 volt side. Again all transformers will be phased.

Although I do like the idea of powering the TIU through its Aux. port with a Z1000 brick,also using its Aux port for uncoupling tracks, a Z500 or Z750 for only switches since my switches will be using there controllers as well as being wired into the AIU and a Z 500 or 750 for all other Accessories and lighting.

Again Thanks

Kerry

Barry,

Already have your new book as well as Rich Melvins DCS DVD. 

Read your book cover to cover, and now I go to it a lot for reference.

Didn't you mention in your book about operating an AIU using a separate power source through its Aux Power Port, or was that Rich Melvin. As it stands right now I have 15 switches planned, and the Accessories are still TBD.( will probably need 2 AIU's). The switches will be controlled with there Remote Controllers as well as being tied into the AIU's, and I plan to have the switches and uncoupling tracks powered by there own dedicated power supply, as recommended elsewhere. ( In fact I think Rich Melvin Recommended it in the DVD).  

As I mentioned earlier in this thread I come from the old HO DC side, I know using AC is easier but it's all new to me, and I have to learn all new ways of thinking, especially since I've been out of the hobby for almost 10 years. Having a 3 1/2 year old great grandson has given me the motivation to get back in the hobby, and hopefully bring in a new young mind.

Again thanks to all who have replied so far.

Kerry

Thanks Barry, that did slip my mind about the TIU having built in TVS.

Kikeehn, that sounds better for channel 1 and 2 power. I would highly recommend using the Aux power for your TIU with two channels being used. If you trip a breaker on the channel 1 power, channel 2 will still be powered and you will have no control over it because the TIU will lose power, unless powered through it's Aux port.

The TIU Aux power port is totally separate from the port used for the AIU. If you use the Aux TIU power you want that to be a dedicated power supply for TIU power only. As Barry said above the AIU gets it's power from the TIU, through it's connection to the TIU. The switch and accessory ports on the AIU are powered separately with a different power source.

Barry Broskowitz

I just check the DCS manual and it does recommend using a Brick to power each channel of the TIU.

Time to watch Rich's DCS DVD again, oh well back to the drawing board so to speak.

Thanks again all

Kerry