# Wiring a wye / reverse loop module



## jimmyG (Dec 27, 2007)

I am building a layout that includes one reverse loop and one wye. I plan to use two 55085 modules to make this work.

Several questions:

1. How would you wire up the wye on my layout? Please refer to the attached layout diagram. I have added the letters “A”, “B”, “C”, “D” and "E" so you can clearly explain where I would create the isolated track section(s) and install the reverse loop wiring/components. Do I need another isolated track section (let's call it "F") just to the left of "D" and before "E". 

2. Related to #1 above, do I need to create isolated track sections that are connected to a reverse loop module on each side of the wye to enable full reverse loop functionality? 

3. Will my trains be able to run through the Wye in either direction if I only create one isolated track section on the wye and wire it up to the reverse loop module?

Thank you for your assistance.


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## Dan Pierce (Jan 2, 2008)

E is not needed as both sides of E are the same.
Reverse loop on the left needs isolation as your pix shows the rails shorted.


Also what is the length of a-b and C-D, these must be longer than the longest train if using metal wheels, A caboose with metal lights can short the rails.


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## jimmyG (Dec 27, 2007)

Thanks Dan. It's good to know I only need to isolate the A-B segment of the wye and wire it up to a reverse loop module. Based on that information, I've ordered two LGB 55085 reverse loop modules - one for the wye and one for the reverse loop.

In answer to your question, the A-B segment is about 8.5' long, while the C-D segment is about 10' in length. I wish they were both longer, but I don't have any more space. I'll therefore have to run shorter trains and/or use plastic wheels.


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## phils2um (Jan 11, 2020)

The attached is what I'd do in your situation. You only need one reverse loop module. Make the segment of track between the wye and reverse loop the track section whose "polarity" is switched by the module. Eliminate the isolations at A, D and E. Add the isolations you need anyway entering and leaving the loop. I'm actually doing something similar using one LGB reverse loop module and sensor segments. It works perfectly and you can enter or exit the wye and reverse loop from any direction. This also solves the switched segment length issue. The connecting segment as you've sketched it is probably plenty long to accommodate your longest train.

Edit added: I'm new to the forum and did not pay attention to the date of the original post. Automatically assumed it was recent. In any case it's what I'd do in this situation.


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## Dan Pierce (Jan 2, 2008)

One reversing unit is ok only if running one train. If running 2 trains you need separate reversing units.


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## phils2um (Jan 11, 2020)

Yes,I assumed there would only be one train at a time on the single track, reversing unit controlled segment as I've depicted it. Does not preclude a second (or more) trains running on the loop to the right of the wye or the loop segment of the revere loop at the same time. I regularly have multiple trains running. 

Attached is what my current outdoor layout looks like.Sensor segments for the LGB 55085 reverse loop module are located where I've sketched in the breaks. I typically have at least two trains running around and often three. It took a little head scratching to get the sensor wiring correct but I've not had any trouble with it. I can approach and exit the controlled segment from any of the three directions and it functions flawlessly. It is mostly true that I can only have one train in the controlled segment at a time. It depends on the routing I've selected and having both trains traveling in the same direction.


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## Greg Elmassian (Jan 3, 2008)

So, if you are running 2 trains at once, and each could hit a "reverse loop section" at the same time, then you DO need 2 reversers. That is the gist of Dan's question.


In your drawing, you can use insulators at x, y, a, d, and then the train running on the loop on the right never touches the reversing loop.


But if you are running DC and are transiting from left to right, you cannot do it, as the reverser will reverse the track you are already on, not the loop on the right as you enter it.


I think on DC you will have to have 2 reversers, on DCC only one will be adequate.


Greg


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## toddalin (Jan 4, 2008)

phils2um said:


> Attached is what my current outdoor layout looks like.Sensor segments for the LGB 55085 reverse loop module are located where I've sketched in the breaks. I typically have at least two trains running around and often three. It took a little head scratching to get the sensor wiring correct but I've not had any trouble with it. I can approach and exit the controlled segment from any of the three directions and it functions flawlessly. It is mostly true that I can only have one train in the controlled segment at a time. It depends on the routing I've selected and having both trains traveling in the same direction.
> View attachment 55954


If I understand this correctly, you already have this wired for dc and now want to change to DCC?

If that is indeed the case, why you you need to do anything to maintain the status quo? The system is already set up to avoid short circuits, and that would include shorting out the dcc circuitry.

Not running DCC, what am I missing here?


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## phils2um (Jan 11, 2020)

Hi Todd, No, I am running DCC and started that way. I assumed the OP was planning to run DCC as well because the LGB 55085 is mentioned. None of the three legs of my wye are long enough to contain trains of the length I want to run. So, it was totally impractical to make one of the legs reversing. Doing it the way I did overcomes that problem.

If the OP is running analog DC then I think Dan may be correct and two reversing units are needed. Even then, what is going to happen to other trains when the polarity is reversed if running analog DC? Makes my head hurt trying to think of the wiring nightmare on an outdoor layout! That's why my permanent outdoor RR started out DCC (actually mixed mfx and DCC).


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## Greg Elmassian (Jan 3, 2008)

you can use the 55085 for DC operation, but there are restrictions, would be good to hear from the OP definitively DC or DCC.


Yep, reversing the polarity on DCC "underneath" a running train is not good... what happens is the train immediately starts going backwards, no mystery.


So, waiting on the OP to verify, also next step is using sensor tracks or short detection.


Greg


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