How many of you all with DCC actually wireup blocks, or districts (I am assuming they are the same thing) with switches that actually power a specific block down? I had a guy at a LHS tell me that even with DCC I should be powering off some sections of track. I thought, why? If I have DCC I can put the locos in neutral. I have a very small layout, most of you all have seen it in THIS thread. I obviously have the 2 mainlines separated, so why else would I need to 'district' my railways?
Let me lead off by saying my layout is using the Digitrax system and incorporating PM42s for power districts. I am planning my layout to have power districts. I'll have a staging section, a mainline section, and the main yard divided into two sections. This is just the upper level of my layout. I don't intend to "power down" or turn off power in any of these sections. The reason I am dividing the layout into power districts is to prevent a short in one district from affecting operations in another district.
bingo chris!!! if power needs do not dictate a booster in a district, then using PM42's makes a LOT of sense, ESPECIALLY if you have turnouts that can be split or reversing loops. if districting is not done, one short will shut down the entire layout. having used DCC at a few N-trak shows, I can say shorts are rare but they DO occur. oh, and the guru suggesting shutting off blocks of DCC trackage is full of hot air IMHO. I've never seen nor heard of it being done, except in cases where layouts were originally wired for dual cab operation and converted to DCC later. I guess you could use the existing switches.... Five, you are absolutely correct that with DCC you can put the lokeys in neutral (correct Digitrax terminology is "dispatching" a loco from the throttle once it has been stopped) the amount of track being powered isn't an issue... the number of lokeys drawing amps is the $64,000 question.... and leads to making determinations about using boosters in those districts. hope this clears it up somewhat!
So guys, here is my opinion : I'm building a medium size layout wich will be totally computer controlled and every pieces of track is always under current. The basic idea of DCC is that locos, swith, etc never have to be disconnected from the DCC transformer. BUT, If you'd like to run several trains at the same time and control them all yourself : - the easy and cheap way is have small track section (just a bit longer than your longer MU locos) that you can turn OFF when you'd like to have a train stop somewehre while you're switching with another loco in your yard... So you can gently prepare the next train to leave with your MP15 and the double stack train that have to enter in your yard will stop automatically before the station area. when the leaving train is ready to go, you'll turn ON the stop section and the double stack will gently enter on a free track... Does this make sense to you???
I have 4 districts on my DCC layout. The ONLY time I power down a district is to check the gauge of a section, turnout or fix a derailment. It is very seldom necessary to power down even for the above conditions. I do have my programmng track also switched between running and programming for convience. But I do believe the little extra effort to have several districts is worth it for the reasons given.
Sheldon: Do you know the purpose of a power district on a DCC layout? I have two power districts on the JJJ&E. Each district has a separate source of power from my Lenz DCC system. I have more than a dozen blocks that I use for block occupancy detection, feedback and signaling . Blocks can also be used for troubleshooting. Stay cool and run steam....
I understand the purpose behind power districts. My question was regarding the purpose behind powering off these sections (other than the programming track).
There is no reason to "power off" these sections. As for programming track; I use it only for programming so there is no power to this track. The only power to the programming track is supplied when you set up a decoder with an address. Stay cool and run steam.....
Actually, there are TWO reasons you MIGHT need to power off a power district, or blocks within a power district (These may differ if you have occupancy detectors on your layout). The first is IF you are operating locomotives without decoders. In this case, you want to be able to power off any track which the locomotives may sit in. (Due to the nature of the DCC signal, a sitting analog locomotive generates a lot of excess heat - powering off the track avoids that). The second is for troubleshooting. It is nice to be able to disconnect a blocks to be able to find where a short is occurring. This does not need to be accomplished using a switch. Paul [ February 28, 2006, 04:38 PM: Message edited by: Paul Bender ]
Is this correct? Power districts are also good idea to split up the power/current/amps. if you have a 5 or 8 amp DCC system with N scale, you do not want a derailment with a full 5 or more amps on the a given track, as that much can weld a wheel to the track. I had read this on some boards. true??? Question: If you have a 3 amp DCC system and one 3 amp booster, and you want to use one for each district, do you need any other hardware to split them up in to the two districts? Thanks
Kozmo, That would make sense to have a dedicated 3A booster for each district if you are going to run alot of locomotives, but my question was geared more towards installing a DPST switch to turn a district off.
My Lenz 100 system(5 amps) automatically shuts down if there is any indication of a short circuit. I've never had a wheel or loco melt down because of a short circuit in 6 + years. Stay cool and run steam....
This is partly true. Of course, where these kind of shorts tend to happen is at the end of long runs of wire where the bus wires are insufficient, and as a result the booster's internal short detection won't trigger. The other reason to subdivide the output of a single booster accross multiple power districts is to reduce the impact to other operators when a short circuit occurs. In other words, if you have a layout large enough for several users, you want to minimize the impact on the users who didn't cause the derailment. In general, I would say there is no gain for a 3 amp booster, so I wouldn't bother. Paul
Warning!! Digitrax answer ONLY!!! with Digitrax loconet, you set the DCC system as the "master" , the booster as the "slave" and connect them with 6 lead wire. setting the db-150 (digitrax booster) as a slave is as simple as running a small piece of wire between 2 unique wiring locations on the front panel. connect the booster to the master via the loconet (be sure to isolate the tracks!!) and viola! throttle commands are "packeted" only by the master command station, the booster only adds amps and passes the packets of info from the master into the slave trackage. The six lead wire is the same wire you can use to "daisychain" the UP-5 throttle plug ins. Again, this is Digitrax nomenclature!! I do not pretend to understand the interconnection of any OTHER DCC system on the market. Hope this helps
ednsfan: Thats basically the way the Lenz system works. I use the Lenz LZV100 command station and the LV 101 of a Lenz 01 Professional powers a second district. The LV 101 is connected to the LZV100 and receives info from the LZV100. The LV101 supplies the power to the second power district. Stay cool and run steam.....
This is partly true. Of course, where these kind of shorts tend to happen is at the end of long runs of wire where the bus wires are insufficient, and as a result the booster's internal short detection won't trigger. Paul </font>[/QUOTE]the ONLY time I've seen welding occur was at the end of a very long district on a n-trak setup. remember, many n-trak mods have 16 gauge zip cord wiring. In the past 8-10 months, a new RP (recommended practice) for n-trak that calls for 12 gauge zip cord is gaining acceptance. clubs that are DCC exclusive will probably upgrade their modules to 12 gauge wire as time passes. something to think about as you are planning wiring for a home layout.
The RP for 12 gauge wire with N-trak has been around for several years now. What's new in the last 8 months or so is the RP for the Anderson PowerPole connectors. BTW, this is an improvement for DC control too, so It's a good idea regardless. Paul
my bad Paul... I thought the PowerPole RP was a part of the RP for 12 gauge wire. I stand corrected. anyone remember the bad old days when you connected the powerpack to the snaptrack with decoder sized wire?? one very scary thought these days !!!
What's this 12 gauge RP for? Feeders? That's a little overkill for 5amps, really. Your typical 12/14 gauge house wiring is rated for up 20amps.
