Is as Single Main Bus Preferrable or Plural Buses?greenspun.com : LUSENET : Wiring for DCC : One Thread
I just got my Digitrax Super Chief starter set and want to begin wiring.Which of these alternate wiring options is best? My first thought was to run four buses with AWG 12 wire, one for each power district and then run 18 AWG up to the track and 22AWG feeders to the rails. I am going to use Tony's PS One Power Shields as well but they only accept AWG16 wire. So I would run 16 AWG from my booster to each of four PS 0ne's (or a PS Four) and then start my four bus runs from there. My concern is that since each district might be 30-40 feet long and have maybe thirty switches, that the number of districts is not enough to isolate a short especially since I am using Walthers switches. Once wired, if I need more districts, I guess I'd need to add more main buses The second option is to run a single 12 AWG bus and tap off with 16 AWG into each PS One and run 16 AWG as my sub-buses. This has the advantage of making it easy to add more power districts if needed without running more 12 AWG wire around my layout. But now each district may be limited in size to no more than 30 feet at most because the track feeders are connected to only AGW 16 wire. Moreover the lenth of my 22 AWG feeders will increase unless I tap off AWG 20 between the sub-buses and the track feeders. So I get more districts but I buy a lot more PS One's and I'm not sure the wire is thick enough.
Since I only want to do this once,your thoughts would be appreciated.
-- Tony Zupcic (firstname.lastname@example.org), February 15, 2003
Wow! This sounds like a large layout. I am picturing 4 districts each 30 to 40 feet in length. With that kind of real estate involved, my guess you will want a multi-operator operation which means lots of locomotives. Do you think your single booster will handle all that?
Where I am going with this is you may tap out your booster and want to consider the significant cost of adding boosters rather than power shields. Go the power shield or PM42 route to sub-district those large districts.
In any case, I would suggest a large AWG to from the booster to the power shields and then from the shields to the buss runs. I do this by using those standard terminal blocks you can get from Miniatronics or Radio Shack. My take is that you have no choice but to use the 16AWG wire at the shields but at least you can make the length of the 16AWG as short as possible by connecting to terminal blocks. Return to 12 - 14 AWG wire for those long buss runs from the terminal blocks. The effort is to control signal loss. Long runs of thinner gauge wire will give you hassles. Don't sweat short runs (12 - 18 inches) of 16AWG.
-- Doug Fraser (email@example.com), March 05, 2003.