MRC reversing loop question/problem...

Discussion in 'DCC & Electronics' started by Chesticus, Mar 14, 2008.

  1. Chesticus

    Chesticus New Member

    I have three reversing loops on my layout. I have put three MRC reversing loop modules on the layout. I am having problems. They are not working. My Challenger stalls coming out of the loop. This is not a new problem. I have read about this very same problem on this site, and that these modules are not able to handle the pwoer requirements or work fast enough for the engines I am using. I am using Bachmann easy command system with a 5 amp power supply (also Bachmann). I have read hear that these modules (MRC) may not be the best for the engines I am running (sound and three engine consists). If these are not going to work, can you recomend anything that will handle what I am using.

    Also, I have read that you want the gap in the loop to be longer than you longest train. I am assuming that by train we are talking about the engines and not about the train (cars) themselves.

    Also, the Challenger seems to go throught the loops just fine with out the cars in tow (at least on the test late last night), but as soon as you attach cars to the engine we get the short.

    I am really tired of this. I just want to run my trains.

    any advice would be greatly appreciated.

  2. steamhead

    steamhead Active Member

    Hi...When "the longest train" is means the WHOLE train (otherwise it would be said "the longest ENGINE..." ). This is because there may be metallic wheels on some of your cars which can bridge the gaps on the rails causing another re-set of the reversing unit, which will cause the engine to short out when it tries to cross over the second gap at the end of the reversing section. You use the word "gap" to mean the whole section, This is not correct. The gaps are in the rails at both ends of the section where they join the rest of the layout.
  3. Chesticus

    Chesticus New Member

    So the train length cannot exceed the length of the "blocked off section" of the track? I do have metal wheels. But I do have plastic rail joiners. I have never heard that the cars passing through the blocked off section of track would cause a problem.

  4. steamhead

    steamhead Active Member

    That is correct....Metal wheels can bridge the gap at the rail joiner and cause a short, which in your case, can reset the reversing unit.
  5. Harold Cole

    Harold Cole Member

    I've got a MRC reversing unit and the reverse section is enough for 4 engines to pass through and with 8 lighted passenger cars i don't have any problems.
  6. 60103

    60103 Pooh Bah

    You should be able to design the reversing section to be most of the track beyond the turnout that defines it. That way, any train you can reverse will fit in the section.
    It may take a bit of ingenuity to devise it.
    Try running shorter trains to see if they work, then lengthen them until it fails.
  7. Here's an idea: Make the turnout switch reverse the polarity as well instead of relying on the automatic reversing switch.
  8. Chesticus

    Chesticus New Member

    Thanks for all of the input. Here is what I did, and it seems to have worked. The MRC unit is rated for some at 1.5 amps and others 2.5, but my set is using the 5amp Bacmann pawer supply. I decided to try it with just the 1 amp power supply that came with the Bachmann DCC. The result is that IT WORKS JUST FINE.

    I think what is happening, and i have read this on other posts, is that the 5 amp power supply is reading a short faster that the MRC reversing module can switch the polarity. Idon't know if I can reset the speed at witch the 5 amp power supply reads the short, but if I can't, at least I have my layout working for now. In the future I will get a better DCC system.



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