wjstixIt wouldn't be a bad idea as suggested to wire the section up to a toggle to work the reversing section manually. If that works fine, then the problem is with the auto-reverser. However, that may not mean the reverser is defective!
+1
greg - Philadelphia & Reading / Reading
It wouldn't be a bad idea as suggested to wire the section up to a toggle to work the reversing section manually. If that works fine, then the problem is with the auto-reverser. However, that may not mean the reverser is defective!
IIRC, the MRC auto-reverser doesn't have a sensitivity adjuster; Digitrax does. It may be you've wired everything OK, but the sensitivity of the AR isn't quite right. On my Digitrax AR it took a couple of test runs to get it set just right so it worked properly every time.
CPbuff I did your diagnostics and have figured out that the brand new AR is failing! 2 AR failures in the last 2 years.
I did your diagnostics and have figured out that the brand new AR is failing! 2 AR failures in the last 2 years.
I had a similar problem when I was using Digitrax AR1s for my reversing sections on my old layout. The Digitrax AR1s worked just fine until I decided to break my old layout into power districts controlled by PSX circuit breakers. The PSX with its solid state relay would trip faster than the AR1. So, I replaced the Digitrax AR1s with PSX-ARs and everthing worked fine once again.
But before running out and purchasing a couple of expensive PSX-ARs, I would install a temporary DPDT switch on that lower reversing section and manually operate the lower loop to make sure that it is wired and gapped correctly.
Rich
Alton Junction
Just get a PSX-AR and be done - more expensive, but they work with nearly anything, and have options for some remote indicators to tell you what's going on.
Digitrax is more or less replacing the AR-1 with the BXPA1, which is a solid state auto reverser, breaker, and block detector all in one, but unless you use Loconet, the block detection feature is pretty much useless. The PSX-AR is an AR and breaker in one as well - if flipping the loop doesn;t fix the short, the unit will completely disconnect power to the loop track. The MRC AR and the AR-1 don't do this.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
OK, so you have a "good" AR that works on the upper loop with no issues entering or exiting the upper loop. Does that "good" AR also work on the lower loop with no issues entering or exiting the lower loop?
Thanks again Randy! I did your diagnostics and have figured out that the brand new AR is failing! 2 AR failures in the last 2 years... I took the last AR I had from the lower loop placed earlier and moved it to the upper loop and everything seems to be working for that loop(upper), so now I have to purchase another AR... but with the luck I've been having with MRC, would a Digitrax AR work on the lower loop even though we have a MRC AR on the upper loop?
It shouldn't matter which way the yellow wires are conencted, as these are the ones that change phase when the reverser flips. One way, it will match the top but not the bottom initially, the other way it will match across the bottom gaps but not the top ones initially. When the gaps are crossed, it should flip the yellow wires so it matches the phase across the gaps.
Even if the AR doesn't work, or if it fails to trip before the main booster, a train should be able to cross one set of gaps, since the phase has to match on one end no matter what. It will fail on the other end if the AR isn't working, but crossing one set of gaps should always work - it would work that much even if the AR was not in the circuit.
OK, that clarification definitely helps. So, that explains the feeder protocol with the MRC Auto Reverse Module (see the diagram below in the next reply). With no feeders connected to the bus, the MRC AR Module receives power from the non-reversing section of track (red wires) and carries that polarity into the reversing section of track. Have you connected the two yellow wires the same way as the two red wires (inner to inner and outer to outer)?
Edit Note: Randy types faster than I do.
Do you have the AR hooked up the right way? Input and output are not interchangeable. Red goes to the main bus, yellow feeds the loop. You should probably have a short bus under the loop and more than one feeder to the rails, with that loop bus powered by the yellow wires from the autoreverse.
Inadequate feeders can cause the autoreverser to not flip, if it does not sense a current that exceeds the trip point. The MRC unit has no adjustment, so it either works or it doesn't. You should get a click out of it if you short the rails, before the system shuts down, if it is working.
Another possibility is that the trip time of the MRC AR is too slow to work with your DCC system - what system are you using? If the main breaker trips faster than the AR, you will have the problem you are experiencing.
Just some clarification for some of you! This is a brand new layout of which is only DCC and I have never owned DC anything. The MRC Auto reverser takes power from the track only ( not the bus) and supplies power to the inside of the loop allowing the loco to continue around, when the loco leaves the loop the AR should? automatically change the polarity to match the track feed leaving the loop. Thats why only one track feed is required , When coming into the AR before the AR gap, the feed is the same as the feed and polarity after it exits the gap leaving the loop! I am working through Ricks suggestions and I will let you all know later!
richhotrainThat is quite confusing. If you removed all feeds from the layout except for one, you would lose power as the loco crossed over from the non-reversing section to the reversing section. You would need at least two pairs of feeders, one powering the non-reversing section and one powering the reversing section.
I assume he still had the reverser in the circuit.
But I still don't understand. It is unlikely that 3 AR's are bad. I remember a previous thread about a short and it turned out to be part of a DC bus, still wired to a DCC system that the OP forgot about.
There is still something missing that neither the we nor the OP realize.
Henry
COB Potomac & Northern
Shenandoah Valley
CPbuff Another update! To isolate the problem, I have removed all feeds from the layout (as I use terminal blocks under the layout for trouble shooting) except for one located on the top track where the "A" is on the diagram
Another update! To isolate the problem, I have removed all feeds from the layout (as I use terminal blocks under the layout for trouble shooting) except for one located on the top track where the "A" is on the diagram
rrinker Easy to test. Bypass the AR. Connect the loop tracks with the feeders matching one of the two tracks, for example, on the top loop, if you have the rail to the top of the digram as A, and the rail towars the bottom as B like where the A abd B are in the top left, then wire the loop the same way so that on the loops ide of the upper right gap, the top rail is A and the bottom rail B. Now a train should smoothly run into the loop at the top right, crossing those gaps with no problem. Main to loop, loop to main. There WILL be a short if you attempt to cross the gaps at the bottom of the upper loop though, because now the polarity is backwards across the gaps. If this works, and there's no reason it shouldn;t, put the AR back in place. If the train will no longer enter/leave the loop at the upper gaps, there is something wrong with the AR. If it goes in, but shorts coming out, reverse the feeds to the AR with the train in the loop. If it now comes out of the loop fine, that points to the AR not reversing. If the AR is not working, then the train should now cause a short at the upper gap, because the loop polarity no longer matches the track on the other side of that gap. ANd if you get a short as soon as you turn on the power - that means you don't have both rails gapped at each end of the loop. Or a feeder from outside the gap connects to a rail inside the gap, or vice-versa. --Randy
Easy to test. Bypass the AR. Connect the loop tracks with the feeders matching one of the two tracks, for example, on the top loop, if you have the rail to the top of the digram as A, and the rail towars the bottom as B like where the A abd B are in the top left, then wire the loop the same way so that on the loops ide of the upper right gap, the top rail is A and the bottom rail B.
Now a train should smoothly run into the loop at the top right, crossing those gaps with no problem. Main to loop, loop to main. There WILL be a short if you attempt to cross the gaps at the bottom of the upper loop though, because now the polarity is backwards across the gaps.
If this works, and there's no reason it shouldn;t, put the AR back in place. If the train will no longer enter/leave the loop at the upper gaps, there is something wrong with the AR. If it goes in, but shorts coming out, reverse the feeds to the AR with the train in the loop. If it now comes out of the loop fine, that points to the AR not reversing. If the AR is not working, then the train should now cause a short at the upper gap, because the loop polarity no longer matches the track on the other side of that gap.
ANd if you get a short as soon as you turn on the power - that means you don't have both rails gapped at each end of the loop. Or a feeder from outside the gap connects to a rail inside the gap, or vice-versa.
Lastspikemike An object lesson here is to wire the reversing loop for fully manual operation and get it to work. Only then fit the auto reverser.
An object lesson here is to wire the reversing loop for fully manual operation and get it to work. Only then fit the auto reverser.
Another update! To isolate the problem, I have removed all feeds from the layout (as I use terminal blocks under the layout for trouble shooting) except for one located on the top track where the "A" is on the diagram, I reversed polarity too and the problem continues, I moved the feed to where the "B" is on the top of the diagram and tried both polarities and the problem continues, so I am going back to thinking somethings wrong with the AR, although all AR's bench tested fine... ( using a process that MRC supplied to me a while back)...
Thnks Rich! Your diagram (all be it crude) does match the the wiring I have in place, per my previous diagram the squares are 1' square and the total layout is 11'W by 12'6"Long...
Yes, polarity is correct... Yes, 2 gaps in the upper loop and 2 gaps in the lower loop!and no feeds inside the loop, only powered by the AR... The diagram you saw, each square is 1' square! so distance apart should not be and issue!
I will investigate further into a possible bad frog before reaching the AR? as I just noticed that the headlight of my steam loco flashes briefly (sitting in the engine house just to the right of the roundhouse) as a normal car passes over the turnout (two turnouts left of the upper AR) which suggests a quick short!
That would seem to indicate you have the shank part wired backwards somewhere. It's stillt he same as I previously posted with the red and black lines indicating polarity. Unless any of those turnouts making the crossover is an electrofrog type.
You have the 2 gaps in the upper right loop, correct? and that track is fed through the autoreverser? And the lower loop,. same thing, 2 sets of gaps, and all track within the loop, inside the gaps, must be powered ONLY through the second autoreverser.
CPbuff Thanks, Again Randy, but I reworked the layout this afternoon per your diagram and now the loco shorts out across the gap in both directions not just one... And too the others asking, its only one loco at a time I am trying to get around the loop, no consist and numerous locos do the same thing!
Thanks, Again Randy, but I reworked the layout this afternoon per your diagram and now the loco shorts out across the gap in both directions not just one...
And too the others asking, its only one loco at a time I am trying to get around the loop, no consist and numerous locos do the same thing!
Will a locomotive run through the loop without a train?
Jim
Like this:
Then the only reversing sections are the two end loops.
If you have room, you can put a second crossover going the opposite way in there as well. Anywhere along the two mains, you can put a crossover, actually. Changing the track at the top makes it a true dogbone.
Can I send you an email at rer@lehighgrads.net and you could scan a rough drawing on paper of what you saying I need to do?
On simple track change - get rid of that short section so signle track at the top, that's where the problem is, there's a wye AND a loop. Have the track on the diverging route of the top turnout that leads to those sidings across the top go to the top of the loop, rather than have the tracks join.
Thanks Randy! I checked the feeds and everything is the way your diagram shows them to be . As a matter of fact I used an ohm meter to ensure the meter shorted at the top loop on both when testing black rail to black rail and red to red... Problem continues! the A and B were to show that when the the rails on the second track (down from the top) returned to the top of the layout the polarity would have been reversed? To check further I gapped the second track from the top (as I have a feed on both top and bottom track ) and problem still exists when the loco crosses the gap at the top... going counterclockwise!
I think Randy nailed it. I saw the A B B A and it didn't make sense to me, but I didn't think to ask about it either. My bad.
Forgive the crudity of the model, didn;t have time to build it to scale or to paint it - but here is a diagram that mau help
Thick red slashes show where the gaps go (approximately). Thin red and black lines show which polarity the track should be in those various areas. I notice int he upper left there is some A/B labeling - if this is the way the feeders are hooked up, it's backwards. Both tracks need to be the same, as shown by my red and black lines.
If I am understanding the track plan correctly - the track to the left loops around in a helix, the track in front passes over that track there in the middle left, no connections between them?