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DCC Wiring of WYE with Reversing Loop on one leg

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DCC Wiring of WYE with Reversing Loop on one leg
Posted by telerailroader on Wednesday, September 15, 2010 11:32 AM

My layout design has WYE that has a reversing loop on one of its legs.  The leg of the WYE with the reversing loop will be on its own power district.  The main line that goes through the other 2 legs and will be on a separate power district.  What would be the best way to wire this for DCC?

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Posted by dehusman on Wednesday, September 15, 2010 12:06 PM

I'm confused about your track arrangement.  One main line can't lie on 2 legs of a wye.

Is the reverse loop entirely on the tail of the wye?

Is the wye "in" the reverse loop? (when you go around the reverse loop you travel over two legs of the wye)

Any chance of a picture or sketch of what the arrangement is?  If the reverse loop in on the tail you have two reversing sections, if the wye is in the loop you have one reversing section.

Dave H. Painted side goes up. My website : wnbranch.com

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Posted by Phoebe Vet on Wednesday, September 15, 2010 1:26 PM

telerailroader
My layout design has WYE that has a reversing loop on one of its legs.  The leg of the WYE with the reversing loop will be on its own power district.  The main line that goes through the other 2 legs and will be on a separate power district.  What would be the best way to wire this for DCC?

A question like this should be accompanied by a track diagram.

Dave

Lackawanna Route of the Phoebe Snow

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Posted by maxman on Wednesday, September 15, 2010 3:07 PM

At the club I belong to we had a situation that appears to be similar to what you're describing.  It is shown in the accompanying sketch.  We have a standard gage branch line fed with a booster and power suppy that feeds the branch and two legs of the wye.  Then there is a dual gage section that forms the reversing section.  The end of this section is connected to a partially dual gage loop that is fed from a separate booster and power supply.

We connected the DCC reverser into the reversing section portion which is between the crossover gaps on the left and the gap on the right.  To simplify the description of this location, the connection was made where the sketch says "dual gage ends".  The reversing section has to be a little longer than your longest train so that you don't span both ends of the reversing section at the same time.

 

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Posted by telerailroader on Wednesday, September 15, 2010 6:13 PM

The attache URL below is a link to layout diagram of my layout.  The WYE I refere to in my original posting is in the upper center of the diagram and the reversing loop is on the right center of the diagram.  How many reversers do I use and where do I place them?

 

http://s936.photobucket.com/albums/ad205/bwaterman1/?action=view&current=TrainRoomV7.jpg

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Posted by Motley on Thursday, September 16, 2010 12:32 AM

Hi neighbor. That is one nice looking track plan, and it's huge! I sure wish I had that much room.

It looks like you have the 2 places for needing a reversing section. One on the wye, and one on your reverse loop.

So you will need 2 auto-reversing units. I reccomend getting the Tony's Trains PSX-AR. They work well and are completely silent, unlike some of the other auto-reversers offered. Just read the manual it tells you where to place the isolated gaps and how to wire it. It's pretty easy.

Let's see some pics of the layout? How far along are you in the building of it?

Michael


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Posted by MisterBeasley on Thursday, September 16, 2010 8:32 AM

You've got one of those "second order" effects that's not immediately obvious.  You will need a reverser for the wye and another for the loop.  That's pretty obvious.  Unfortunately, the "obvious" arrangement of having the reverser-controlled section of the wye take you over to the loop isn't something you want to do.

That arrangement would force you to "daisy chain" two reverser sections.  When a locomotive crosses that boundary, both of the reversers will detect the situation and both will try to flip at the same time, resulting in the two of them fighting each other.

I would also contact Tony's Trains and ask them about this specific situation where one reverser must lead to another.  The PSX-AR is "tuneable" to some extent, and they may have suggestions on how to set the parameters so that one of the reversers will flip before the other, avoiding the conflict.

The PSX-AR units, by the way, also contain circuit breakers, so when you put one in it can double as the circuitry for your power disctrict.  I have a pair of the older PS-REV units from Tony's, and they have performed flawlessly for years.

It takes an iron man to play with a toy iron horse. 

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Posted by Phoebe Vet on Thursday, September 16, 2010 10:22 AM

If the section of track that contains the wye turnout is a reversing section, then why does the loop have to be reversing?

If you put the insulated joints in the normal location, when the train crosses the non conforming insulated joint the wye will reverse, eliminating the short.  Why would you want to reverse the loop as well?

Dave

Lackawanna Route of the Phoebe Snow

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Posted by telerailroader on Thursday, September 16, 2010 10:49 AM

Thanks for the sugestion to look at Tony's Trains reverser.

As for the questions regarding the layout.  The layout is currently under construction and is located in a room in the basement of my house in Littleton, CO.  The layout is N Scale and the room is 17' x 18' .  Most of the major benchwork is completed and about 50% of the sub roadbed has been placed.  The only trackwork that has been completed so far is for the staging yard that is under the pennisula that has the WYE.  As for posting pictures, I don't know if anybody would be interested in seeing a lot of benchwork.

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Posted by superbe on Thursday, September 16, 2010 10:55 AM

Your track plan and questions have raised my curiosity, and it will be interesting as to the solution.

Another question I would ask would be what happens to the track after entering the tunnels in both the upper left and lower right corners. There is one rail going in and two coming out creating the possibilities for more loops.

Place your finger on one of the rails (inside for example) and follow it around until you come back to the starting point if you don't end up on the same rail (outside for example) you started on you have a reversing loop.

Happy Railroading

Bob

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Posted by MisterBeasley on Thursday, September 16, 2010 10:56 AM

Phoebe Vet

If you put the insulated joints in the normal location, when the train crosses the non conforming insulated joint the wye will reverse, eliminating the short.  Why would you want to reverse the loop as well?

That's true.  The loop could be powered off the non-reversing main.  It would not, however, be in the same power district as the rest of that track, but given the overall layout that should not be a problem.

Phoebe Vet's solution saves the cost of an auto-reverser and eliminates the two-reversers-fighting-each-other problem as well.

It takes an iron man to play with a toy iron horse. 

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Posted by CSX Robert on Thursday, September 16, 2010 11:17 AM

You have two reversing sections on that part of the layout, but you do not necessarily need two auto reversers, or even one, though it might be easier to wire using auto reversers.  FIrst, look at the section between the wye and the loop.  To pass through the turnout between this section and the wye, the phase of this section has to match the phase of the leg of the wye that the turnout is aligned for.  If you configure this section to swap it's phase when you throw the turnout, it will always match the leg that it is aligned for and you won't need an auto reverser there.  Likewise, to enter or exit the loop, the end of the loop you are passing through has to match the phase of the section between the loop and the wye.  If you power the loop from that section and also configure it to swap it's phase when you throw the turnout for the loop, you won't need an auto reverser there.

The are several ways to have control of the turnout also control the phase of a section of track.  Here are juat a few:

If use a DPDT switch to control the turnout, you can replace it with a 4PDT and use two poles to control the track phase.  If you are using solenoid operated switch machines, you can use Atlas snap relays wired in parallel with them.  If you are using Tortoise switch machines, you can use the built-in DPDT contacts; however, this solution has the disadvantage of causing the tracks to be dead during a poriton of the turnouts thow.

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Posted by CSX Robert on Thursday, September 16, 2010 11:26 AM

Phoebe Vet

If the section of track that contains the wye turnout is a reversing section, then why does the loop have to be reversing?

If you put the insulated joints in the normal location, when the train crosses the non conforming insulated joint the wye will reverse, eliminating the short.  Why would you want to reverse the loop as well?

That would work, as long as you don't have one train cross the boundary at the wye and  another cross at the loop at the same time

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Posted by telerailroader on Thursday, September 16, 2010 11:45 AM

The attached link should answer some of your questions regarding the layout design.  The tunnel track is now visible and it should be more clear as to where the in's and out's of each tunnel are located.  The only track that is not visible in this picture track in the tunnel in the upper center and the track in the tunnel in the lower right.  Both of these tracks go to the staging yard under the pennisula that has the WYE (Keddie WYE).

http://s936.photobucket.com/albums/ad205/bwaterman1/?action=view&current=TrainRoomV7-1.jpg

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Posted by Phoebe Vet on Thursday, September 16, 2010 12:15 PM

Insulate both rails at the red dots.

The blue highlighted section is your reversing section.

Dave

Lackawanna Route of the Phoebe Snow

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Posted by CSX Robert on Thursday, September 16, 2010 12:46 PM

Phoebe Vet

 

Insulate both rails at the red dots.

The blue highlighted section is your reversing section.

 

Again, that will work IF you won't be passing through both ends of the blue section at the same time; however, since there is a passing siding in the blue section, I would think there would be a good chance that you would be doing that(actually, you could pass through both ends at the same time as long as the phases match when you pass through them).

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