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
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!
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.
--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, 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)?
Rich
Edit Note: Randy types faster than I do.
Alton Junction
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.
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?
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?
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.
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.
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.
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