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Digitrax AR1 Brand Selective

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  • Member since
    June 2011
  • From: Loveland, Colorado - Rural
  • 366 posts
Digitrax AR1 Brand Selective
Posted by rgengineoiler on Saturday, March 9, 2013 8:22 AM

I have my AR1's installed now on my new layout design and was testing with a KATO F3.  All was ok.  Ran an Intermountain SD40T-2 and it stalled on one of the reverse sections and then another.  Started adjusting the TTC and could get the Intermountain to run through ok but then the KATO wouldn't.  Since then I have been trying all my Kato's and all my Intermounmtain engines and the AR1 seems to be prone to reject the Intermountain engines.  Haven't gotten far enough to  try my Atlas Engines yet and will today.  Has anyone else had this issue and is there a cure?  This problem exists on a couple of areas that are not near turnouts and one is near a turnout.  It seems that the Intermountain engines won't trip the AR1's at factory default settings but the KATO's will, which includes F3's, PA1's and SD45's.  Is it power draw of one brand as opposed to the other?   Appreciate any Ideas.  My system is Digitrax Super Chief Xtra.     Doug

Tags: Digitrax AR1
  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Saturday, March 9, 2013 8:37 AM

How long are the reversing sections?

If the TTC adjustment doesn't solve the problem. you may simply need more feeder wires in the reversing section.

Rich

Alton Junction

  • Member since
    June 2011
  • From: Loveland, Colorado - Rural
  • 366 posts
Posted by rgengineoiler on Saturday, March 9, 2013 8:59 AM

Feeders are spaced no more than four feet max and the sections are no more than five feet max.  Doug

  • Member since
    July 2008
  • 1,206 posts
Posted by mfm37 on Saturday, March 9, 2013 9:21 AM

I would agree that more feeder wires are required.

Ar1 and any auto-reverser or circuit breaker detect a short circuit then apply a pre designed solution to that short circuit. AR1's swap phase of their outputs to correct the short. Circuit breakers cut power. That's really all they do and there is not much difference in them except for the different solutions.

So when a locomotive metal wheel bridges the gap in two isolated rails that \are not of the same phase, there is a short and the AR1 goes into action. Since all brands of locomotives you have tried have metal wheels, there really is no difference. The current carrying capacity of your feeders and bus back to the Ar1 is more likely the issue. Add some feeders to the reverse loop/section.

Martin Myers

  • Member since
    June 2011
  • From: Loveland, Colorado - Rural
  • 366 posts
Posted by rgengineoiler on Saturday, March 9, 2013 10:09 AM

Ok Martin,  I will work on that today and see what happens.   Doug

  • Member since
    February 2005
  • From: Vancouver Island, BC
  • 23,330 posts
Posted by selector on Saturday, March 9, 2013 10:38 AM

The other thing to try, if all else fails, is to stagger the cuts in the rails so that the gaps are not perfectly transversely situated across from each other.  Many AR manufacturers recommend this practice up front just to avoid problems at gaps.

Crandell

  • Member since
    June 2011
  • From: Loveland, Colorado - Rural
  • 366 posts
Posted by rgengineoiler on Saturday, March 9, 2013 11:49 AM

I hope I don't have to make that change Crandell as that would be a major operation.  I have read about staggering the joints but it says nothing about it on the AR1 instruction sheet.  Anyway I'm working and testing the problem.  Thanks,  Doug

  • Member since
    August 2011
  • 805 posts
Posted by narrow gauge nuclear on Monday, March 11, 2013 11:01 AM

As noted by all, it appears that you don't have the conduction, (low ohmic connection), needed to draw the current required to trip the AR-1. 

The buss wires and feeders are critical here.  I use #12 solid copper wire as my main buss and use heavy, #18 gauge solid wire track feeders to a two screw lug barrier strip just under the holes for the very short, (under 2-inch long), 24 gauge final track feeders.  I feed the track to the center of every 3 foot flex section, thus, I am never more than 18" away from a very heavy copper bussed supply of power anywhere on my track.  To some, this is overkill, but I have never had an issue with any DCC accessory or engine........Too much heavy copper near the wheels and accessories at all times to allow for high resistance issues fouling the DCC.

Richard

Richard

If I can't fix it, I can fix it so it can't be fixed

  • Member since
    June 2011
  • From: Loveland, Colorado - Rural
  • 366 posts
Posted by rgengineoiler on Monday, March 11, 2013 3:01 PM

Thanks for reply Richard.  My bus is 14 gauge and 18 gauge feeders with a 3 inch 22 gauge attached to the 18 gauge soldered to the track never more that four feet.  I solder everything in wiring except for the screw terminals on the terminal blocks.   I did add an extra feeder to one of the problem areas and that has cured the problem at that point.  I have been tweeking the TTC also and the other areas are ok now except for two Atlas RS3's which hesitate but keep moving.  I am N Scale and have been for almost forever and have good reliable equipment no more than 2 years old.  I decided that default for the AR1's was probably set for HO scale so I backed off the AR1's to .25 amps then turned them up 1/3rd turn and two more very very slight tweeks and that is the success that I have at this time.  Now just the RS3's and I will be happy.  In this new build and me being new to DCC I read for a year before even starting.  I still have several engines to convert also.  Really keeps me thinking.   Doug

  • Member since
    January 2023
  • 1 posts
Posted by PeteyG on Friday, January 13, 2023 9:39 AM

I realize this is a long shot for a 9 year old post but I am having the exact same problem.  AR1 works great except for atlas R3 locomotive on 1 of my 2 AR1 installs.  Did you ever get this figured out and if so do you remember what you did?  Thanks!

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Saturday, January 14, 2023 9:09 AM

PeteyG

I realize this is a long shot for a 9 year old post but I am having the exact same problem.  AR1 works great except for atlas R3 locomotive on 1 of my 2 AR1 installs.  Did you ever get this figured out and if so do you remember what you did?  Thanks!

The OP hasn't posted in over 5 years, but he did indicate that he solved the problem by adding more feeders and playing around with the TTC (Tunable Trip Current Adjustment).

In your case, make sure that you have enough feeders inside the reversing section and also lower the current with the TTC adjustment. It apparently is not tripping fast enough to accomodate that Atlas RS-3

One issue with the AR1 is that it doesn't work well as an analog device when solid state devices are also present on the layout. For example, a solid state PSX circuit breaker will trip faster than an AR1 with its mechanical relay.

And, of course, make sure that your reversing sections are longer than the longest train passing through them.

Rich

Alton Junction

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