5 amps is plenty of power for most home layouts. I ran my 25 x 50' layout with a 3 amp DCS50 Zephyr with up to 5 operators, but I did not have a plethora of sound units or lit passenger cars. So unless you're running multiple 4-sound-unit MU's, 5 amps should be enough for the whole layout. I would use 14AWG wire for all track wire busses. Digitrax recommends only 6-conductor flat phone-type wire for the LocoNet throttle bus (parallel, not twister pair like CAT5).
Since you already have both the DB150 and the DCS51, you might as well use both with the Zephyr as the brain. I would place the Zephyr in the biggest yard and use it for the yard switcher job. I would run a seperate wire bus under that yard and have the Zephyr power it. Completely isolate the yard from the mainline and from any other track bus, but connect it with both a ground wire and the LocoNet bus to the DB150.
With the DB150, I would place it near the center of the layout's track milage. This will reduce voltage drop as much as possible at the ends.
With the PM42's as circuit breakers, I would wire each yard (other than the Zephyr powered one) as a block run by a PM42 section. Also, if you have any switching districts, they, too, would get their own block. Switches are where most shorts happen, so isolating these areas to prevent one misaligned switch from taking down your mainline may be important to you. With whatever is left, cut up the mainline equally between them. It's no big deal unless you plan to do block detection and signalling. That's a whole different kettle of fish.
Use the Zephyr Xtra as the coommand station, it has more features, such as CV readback and a dedicated program track, than the DB150.
You can hook a PM42 to each, and have each system power 4 power districts, although the ones driven by the Zephyr will have too be ones with fewer locos because of the lower current compared to the DB150.
If the layout is physically large, place the DB150 some distance from the Zephyr so the track power bus wires can be kept shorter. And don;t forget to run a wire the same size as your bus wire from the GND terminal on the Zephyr to the GND terminal on the DB150 and also to the GND terminals on the PM42s. You also need a smaller wire between Config A and GND on the DB150 to make it a booster only.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I have an HO scale layout running Digitrax DCC. It's a fair size layout with 10 hidden staging tracks underneath.
I own both a DB150 (5 amps) command station and a Zephyr Extra DCS 51 command station (3 amps). I'm not sure which one to make the main command station and which to make a booster?
In addition I have two PM42 breakout boards that will allow me to subdivide the layout into 8 power districts for short circuit management (staging, yard, engine terminal, main line, paper mill yard etc)
My first thought was to make the DB150 the command station. The Zephyr extra would be the booster. But not sure if this is best? Also not sure where to put the PM42s in the mix? Any thoughts on how to put the whole thing together for the best effect?
Thanks and suggestions very welcome!
Bernard