I'm tuning up my wiring plans and acquiring the wiring for my new HO layout. I've got one issue where I'd like some confirmation. One of my reversing loops will have an engine yard that branches off within the loop. The loop will be controlled by a OG-AR. I plan to isolate the engine yard as a separate subdistrict, fed by an OG-CB. I want to be sure I understand I'm not creating a problem. I understand how a loco (train) entering or exiting the reverse loop creates a short on loop entry or exit and causes the polarity for the loop to quickly reverse and all goes nicely. Can you confirm the same occurs when a loco enters or exits the (electrically separate) yard branching from the reverse loop; i.e., the yard always stays the same (it has no auto reverser), and the reverse loop (via the OG-AR) simply reverses polarity when it needs to when a loco enters / exits the yard? That's the conclusion I've come to but not 100% certain.
So if there are 2 trains (locos) involved, one entering and then proceeding towards exiting the loop and another entering the loop from the yard (while the first loco is progressing through the loop), I presume the loco running thru the loop happliy continues on its way even if another loco then enters the loop from the yard and causes a polarity flip?
This is stretching my current (no pun intended) understanding.
Paul
Modeling HO with a transition era UP bent
peahrens I presume the loco running thru the loop happliy continues on its way even if another loco then enters the loop from the yard and causes a polarity flip?
I presume the loco running thru the loop happliy continues on its way even if another loco then enters the loop from the yard and causes a polarity flip?
Not quite. The loco that is running through the loop might pause momentarily when the phase shift occurs, and then resume speed, as if the power was turned off and quickly back on.
peahrensSo if there are 2 trains (locos) involved, one entering and then proceeding towards exiting the loop and another entering the loop from the yard (while the first loco is progressing through the loop), I presume the loco running thru the loop happliy continues on its way even if another loco then enters the loop from the yard and causes a polarity flip?
The OG-AR is a solid-state, 4-amp device. The OG-CB also supports 4 amps. Unless you really think it's necessary to isolate the engine yard from the loop, I would simply run them both through the OG-AR and forget about the extra breaker.
Without a track diagram, it's hard to say how best to wire this. However, I think you could be asking for trouble by asking the auto-reverser to mitigate issues between the two ends of the reverse loop and a third entry point from the yard. Letting the OG-AR handle the yard eliminates that problem.
These solid-state units, by the way, are very fast. You probably won't notice the interruption as the polarity flips.
It takes an iron man to play with a toy iron horse.
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Thanks for the comments. I've added a diagram above. The engine yard is the lower one. Sounds like simplicity (combining it into the attached reverse loop OG-AR subdistrict) may be adviseable. I thought keeping the engine yard separate would be helpful in knowing where any short issues might be occurring, but maybe that's overkill for a relatively simple layout. I just wanted to ensure I understand the issues before deciding.
I have another (freight) yard atop but have the option of starting the reversing loop to the left of the yard turnout, which would leave the yard as an extension of the main line's OG-CB subdistrict. If I locate that reverse loop's isolation to the right side of the yard switch the yard would float with the loop's OG-AR.
I've got 2 OG-ARs on the way and 2 OG-CBs. One OG-AR for each loop, one OG-CB for the "mainline tracks between the loops, and the 2nd OG-CB (optionally) for a yard. The program track (with appropriate switch for program/operate) will be the weird extension off the left of the engine yard. All fed by a 5A NCE PHPowerpro.
I second what MisterBeasley said. Have the yard as part of the reverse loop and everything is simplified.
I'm inclinded to follow the advice above.
Just for my complete understanding, one additional question. I was reviewing the many pages of Alan Gartner's "Wiring for DCC" and see that (if I understand things) another option might be to make the connecting section between the reversing loops the "reversible" part (with OG-AR) and to have all the rest (primarilily the 2 loops) be the "main" OG-CB subdistrict that does not reverse. If that could work, only one OG-AR would be needed (for the connector main that goes into the reversing part of the associated turnouts) and one OG-CB for the rest. Do I understand this right? If possible, a reason not to do this would be the rather short section that the (right, outer, mainline) reversible mainline section would comprise, requiring very short trains if lighted passenger cars were used. Another reason (for me) is that it's more confusing, as I am used to thinking that reversing "loops" need polarity change when shorts occur, rather than the mainline itself flipping to match the entered/exited loop. Am I understanding this correctly, and is there a strong preference on which way to go...reversible loops vs. reversible connected mainline(s)?
I can see operating 2 trains at once, sort of chasing each other, using passing tracks, reversing (or not), etc and how they may enter/exit the loops with turnouts thrown for reversing or continuing on the larger continuous "loop" is something that seems logically ovewhelming until I get to do it. I want to have all options to operate as I please.
I appreciate your patience with my questions...I find this fairly confusing. I know the 2 OG-ARs on the loops and an OG-CB on the main will work and it makes sense to me, so that's my base case plan. It's not a matter of saving one $25+ component, rather what is most practical/recommended and understanding why.
Your track configuraion is relatively complex, so your objective should be to keep the wiring and the reversing sections as simple as possible.
One way to do this is to keep the mainlines, the turnouts, and the yards, phased the same way for electrical purposes. That makes it easier to visualize the reversing sections as you operate your layout.
Sometimes turnouts need to be included inside reversing sections, and other times the turnout becomes the entrance or exit to the reversing section. That complicates the wiring and the reversing sections, making it difficult to visualize the reversing sections as you operate your layout.
If I follow your track diagram correctly, you do have two reversing sections, and it appears possible to keep your mainline, turnouts, and yards, all phased the same way. Therefore, each of the two reversing sections can consist entirely of mainline track without any turnouts or yards incorporated into either reversing section.
It is somewhat challenging to describe the two reversing sections without having access to your track diagram, but let me give it a try.
The first reversing section is the left side of the loop that forms the figure 8. The reversing loop is the inner most of the three tracks on the left side that forms the mainline across the top of the track plan. If you gap the rails of the mainline at the top center and also right after the figure 8 crosses over itself, just before the turnouts on the upper right portion of the diagram, you will completely isolate that reversing loop.
The second reversing section is the portion of the figure 8 that crosses under itself. If you gap the rails on that section of the figure 8 between the turnouts, you will completely isolate that reversing section.
My only concern is whether that second reversing section is long enough to accomodate your longest train. it looks to be somewhere between 4 and 5 feet long.
Assuming that works, and it seems to me that it will, all of the turnouts and the two yards can be wired the same way, in phase, and as part of the main section of the layout rather than as part of either reversing section.
Rich
Alton Junction
peahrens I've added a diagram above. The engine yard is the lower one.
Texas Zepher peahrens: I've added a diagram above. The engine yard is the lower one. Yes, with that plan I would put the main yard at the top in with the mainline power and the loco facility (lower) on in the same power as the reversing loop.
peahrens: I've added a diagram above. The engine yard is the lower one.
You can have both yards wired in phase with the mainline. I have colored one reversing section in red and the other in blue. The circles represent the locations of the gaps.
Thanks for the various considerations & ideas. I decided to make things relatively simple.
a) The mainline(s) will be the right side inner and outer turns, including the 5-track ("upper") yard (since trains will enter it from the right hand mainline outer turn)
b) the (physically) "upper" reversing loop will be the red loop in the note above, extending to include the inner curved crossover turnout
c) the (physically) "lower" reversing loop section will be the left hand loop with its passing track and include the funny engine yard that branches off the (inner front) passing track
All this will use 2 OG-ARs (one for each reverse loop) and one OG-CB (for the mainline connections and the upper yard. I liked the simplicity of this approach as I can readily relate to the physical sections, loop and passing track electrical sections are long, etc. I discoved it was very important (not optional) at which end a couple of crossover turnouts got the electrical gaps. The way the setup should work is the reversers will function when using the crossovers into/out of a reverse loop (actual reversing) but not need to function when the crossovers are on straight through mode, where trains can run continuously without reversing.
As an aside, I got an under layout shelf made where I mounted the circuit boards, NCE PowerPro, room for other items and tested it on the workbench with my 1st loco (Athearn Genesis GP9). All seemed to work normally, including short protection by each subdistrict cuircuit board. I've started laying track...got the 6 turnouts on the right installed (prepped for Torti) and now laying connecting flextrack. I need to get my turnout control panel built...have all the components. This may take awhile.
Thanks again to all.