DCC from a Dummy

Cowboy Jan 18, 2011

  1. Cowboy

    Cowboy TrainBoard Member

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    Stupid question and please excuse the new guy into the hobby.

    I have done tons of reading on DCC Wiring. Here are some of the links I have been to:
    NMRA - DCC Home Page
    http://www.dccwiki.com/Introduction_to_DCC
    DCC Primer | Tony's Tips at Tony's Train Exchange.
    Marcus DCC for Dummies

    From my understanding it appears that you should run the main power lines around your track (red & black) and then do drops that are soldered to the track. These drops should be no more than 12".

    You should also run boosters to long runs and separate runs. The reading also suggests the idea of circuit breakers and on/off switches so that you may isolate a section of track for troubleshoot.

    On this diagram I am trying to capture the concept so that when I have finished my benchwork I have started wiring correctly.

    [​IMG]

    Remember, this is only conceptual. I have not done my trackplan yet but it will have some long straight runs and some different sections. There will be no reverses or wyes at this time.

    Please, please point out the error of my ways and feel free to point me to another website so that I can become educated.
     
  2. woodone

    woodone TrainBoard Member

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    I am uncertain just what you have shown. The on-off switch does what?
    Track B is not connected to anything, just the terminal strip. I see no connection to the buss where the B track is attached.
    Can you clear up were power is on terminal strip?
    As it is now you need to have feeders of track B going to the same buss as track A.
    Now if you want to be able to turn off and on track B, you put a DP switch between the track and buss.
     
  3. RBrodzinsky

    RBrodzinsky November 18, 2022 Staff Member TrainBoard Supporter In Memoriam

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    Cowboy,

    Unless you feel a real need to have a section completely off and isolated, there is really no need to worry about turning off tracks with DCC. Plus, if you decide to put in circuit breakers to protect logical blocks of the layout, then, if you use the PSX breakers, you can actually turn off the section with it!

    As to boosters, unless you are building a huge layout, there isn't a big need for them. I run the entire JACALAR from a single Zephyr.

    Yes, your 22 or 24 awg feeders should be nor more than 12" long, but, if your main buss is too far away, you can always put in some 16-20 awg "branches" (or, even 12-14). What you are trying to prevent is signal loss due to resistance.

    I would say you have the basic hang of it, and don't be afraid to ask specific questions. Once you actually start planning your layout and working the details, you will realize how simple it really is, even with lots of info thrown at you (I know I did).
     
  4. Cowboy

    Cowboy TrainBoard Member

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    Thanks! That statement alone helps a bunch.
     
  5. screen48

    screen48 TrainBoard Member

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    Good lesson here.
     
  6. Gats

    Gats TrainBoard Member

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    Cowboy, I have used your image to create an example of using a circuit breaker, power bus and isolation switches which may help you gain a better understanding;

    [​IMG]

    The bus (large rad/black wire) can be duplicated with another circuit breaker to create power districts. The track wiring can be directly connected to the bus by soldering or a 'suitcase' style connector or even a terminal like you indicated in your first post.
    The replies by woodone and Rick apply and are great recommendations. I used terminal strips to distribute the track power on my layout allowing me to break up the power bus if any problem arose.

    [​IMG]
     
  7. Cowboy

    Cowboy TrainBoard Member

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    Gary,

    Thank you Sir, that helps my conceptual understanding.

    One question about the picture you provided: The wires coming off of the terminal strip (heading towards the bottom of the picture); are they feeder wires or are they "branches" to the feeder wires?

    Also, would you mount the "optional" switches close to the command point or would you not run the wire that far?

    .. James
     
  8. Mike Sheridan

    Mike Sheridan TrainBoard Member

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    Your question actually highlights the downside of using isolation switches with DCC for more than a few specific areas where they are really needed. You either have to put the switches out near the section (in the local wires) so they are scattered around OR if you mount them centrally then you then have to effectively run another pair of bus wires out to each controlled section, which is moving you back toward the complexity of a DC block system.
    As RB said, you don't normally need switches with DCC. Adding them, or indeed power districts, without good operational reasons is just increasing cost, complexity and failure points. KISS :)
     
  9. Gats

    Gats TrainBoard Member

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    You're welcome, James!

    The wires off the bottom of the strip go to the tracks themselves, in this case in a yard. The wires at top are the power bus wires, in this case bus 1, one pair in and the other out to the next terminal strip.

    I would have them close to where they are controlling. You can have the bus wires come into the switch/switches and then onwards with the tracks you wish to switch off coming direct from the switch. If close enough you can use the feeder wire but you may have more than one feeder to a particular track. Then you would have a separate bus from that switch to terminals closer to each of the feeders.
     
  10. Railroad Bill

    Railroad Bill TrainBoard Member

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    I do an N-scale DCC (Zephyr) layout and have had success with a simple approach. I made a bus spine (16 ga. red, black wires) as long as needed to span the two drops (22 ga.) farthest apart; spliced branches into the spine where needed (suitcase connectors) to bring bus wire near other drops; used 8" drops; join drops/bus with euro connectors. All connectors are available at RadShk and cheap enough. The euro connectors are solderless and do not require special terminators (last pix given seems to be an example.) Often join 2 or 3 drops at one connector.

    I have power routing switches and use that feature to make isolated staging tracks where I shut off DC engines when not being used.

    Hard to say if any switches would be needed for power districts, as this is properly a function of the size of your layout and how many operators you will entertain at one time.

    DCC wiring is far simpler than DC wiring; so much so that I would recommend doing DCC from the get go. Bite the $$$ bullet now. All them switches are a thing of the past.
     
  11. dstuard

    dstuard TrainBoard Member

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    The "optional" switches shown are there primarily for troubleshooting, where you could turn off power to a section of track to help isolate a problem (note the track sections need to be isolated via insulating rail gaps as well). The switches would normally remain closed, so are best located "under the hood". Even easier would be to use terminal strips as Gary did. Disconnect is quick and easy if required, otherwise leave it alone.
     
  12. Cowboy

    Cowboy TrainBoard Member

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    That is an excellent point. I had not considered that. Thank you.
     

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