Hi everybody! I'm brand new to the TrainBoard and have about a million questions to ask. For the last several days I have been reading the past posts of this forum. Although I have garnered a lot of tips and helpful hints, I have not found anything on the topic of DCC bus lengths. If you look at the track plan in the link below, it will help to visualise what I am planning to do. If the DCC track bus were to start near the turnout adjacent to "Summit Curve" and then run counter clockwise under the benchwork to the south edge of the bench near the lower turning loop, it would have to be over 35 feet in length. Everything I have read indicates that that is to long for good DCC performance. I think that it would be best if I locate the DCC controller (A DigiTrax DCS 100) somewhere under the San Bernardino Yards. Then I can install a split bus that will be no more than 20 feet in each direction from the controller to the end of track. With the controler underneath the bench near the yard, I need to find a place for a programing track. I would perfer to have the program track located under the bench work at Cajon Summit. That way it would be easily reached from a small work bench I plan to build next to the layout at that location. If not, I could put in a DPDT switch on the front of the fascia and use either the passenger terminal track, one of the Pullman Car Maintence tracks or maybe even one of the engine facilities tracks for a programing track. Those are my thoughts for now. Am I on the right track (no pun intended) for success? Thanks! GM I'm not sure of the protocol when editing an original topic post to include more questions so I will just add them rather than start anorher topic Click here to view full size Preliminary Electrical Plan Drawing. I suspected right from the start that it would be necessary to create some power districts. I believe they are necessary for two reasons. One is so that operators in the yard will not interfere with operators on the main line and in the LA Switching district. The other reason which is the reason for this thread, is due to the length of the track bus if it is not subdivided. My plan is to make three power districts as follows: </font> The LA Bus will power the LA Switching District and that portion of the Mainline installed below.</font> The Yard Bus will power the Yard tracks and that portion of the dual mainline tracks passing through the yard</font> The Desert Bus will power the Cajon Pass, Desert area and the Mainline tracks under the Summit.</font> I did some computations on the voltage loss using 16AWG wire for the bus and found that gage is marginal at a length of 20 feet. I decided to step up one size and use 14AWG for all track bus wires. The added expense is marginal so we will not worry about costs here. Am I correct in assuming that the three turnouts which will be hidden under the scenery can also be powered directly of these buses? (1 turnout on the LA Bus, and 2 turnouts on the Desert Bus) Equipment is next on the list: </font> Digitrax DSC100</font> Radio controled Cabs</font> Tortise Turnout motors</font> Hare switchmotor controler</font> Tony's Trains Power district boards</font> Once we get the Track bus figured out, I sure hope we can get into the good and bad features of the equipment listed above. Thanks for your help! GM [ February 05, 2006, 09:43 PM: Message edited by: GM ]
GM: welcome to Trainboard. You can divide your layout into power district. Each power district will have it's own bus lined. I'm using a Lenz 100 system and have divided the JJJ&E which is much smaller than your layout into two power district. The main Lenz system is wired to both districts. An auxillary command station controls the second power district and is wired to the main command station. One handheld can control the movements of loco's through both power districts. I use three handheld controllers on the JJJ&E and they each can control the entire layout. It sounds complicated, but it really isn't. I'm sure Digitrax has comparable setups available to you. Stay cool and run steam......
Depends a bit on whether you plan to only be a solo operator or have others in for operating sessions. I'd split that into at least 3 chunks I think, with a DCC circuit breaker for each. Make the yard one district, and main line eest and west the other two. If you plan on having sessions with others you might break it down a bit finer - maybe 5 chunks. That is purely so when one area has a problem with a short it doesn't stop everyone else, and also makes finding the problem a bit easier. If possible have the program track off the layout - it's safer that way.
I place the programming track on a small isolated siding. The only power to the programming track comes from jumpers to the programming terminals on the command station. The programming track is isolated from the mainline by plastic railjoiners. Stay cool and run steam.....
The main reason you would split your layout into power districts is the number of locos you wish to run simultaneously. If the collected locos draw more than the capacity of the power supply (e.g. 2.5 Amps with a Digitrax Zephyr), you would need another district. Bus runs of 35 feet should not be too much. The local modular club (www.hotrak) regularly sets up with runs at least this long. A helpful resource might be the Yahoo Digitrax group. I know some of our members are contributors and/or do "research" there. Andrew
