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Reverse loop isolation and where to power?

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  • Member since
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  • From: Juneau AK
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Reverse loop isolation and where to power?
Posted by scookam on Monday, August 15, 2011 9:41 PM

Howdy

I am somewhat overwhelmed with some of my wiring and my have bit off more than I can chew.I sent along these pictures with a few questions hoping for guidance. The first pic is where the reversing loop comes back to itself. I marked with tape red for one idea and green for another as where to isolate and use an mrc auto reverse module. The other pic is an idea for a yard within the reversing loop. My module is rated for 5 amps and my dcc is prodigy advance rated at 3.5 amps. I'm just wondering if it maybe too much yard for the module to wire all that track to. If I then bought a booster would I wire that to just the reverse loop? Any help, to any of these questions, I would thank you for.

Scookam

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Posted by Johnnny_reb on Tuesday, August 16, 2011 12:22 AM

I assume you are following some kind of track plan, so if you would post a picture of said plan with the reversing loop marked. We should be able to help you.

Johnnny_reb Once a word is spoken it can not be unspoken!

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Posted by richhotrain on Tuesday, August 16, 2011 5:20 AM

scookam

Howdy

I am somewhat overwhelmed with some of my wiring and my have bit off more than I can chew.I sent along these pictures with a few questions hoping for guidance. The first pic is where the reversing loop comes back to itself. I marked with tape red for one idea and green for another as where to isolate and use an mrc auto reverse module.

Scookam

Scookam,

Either set of gaps will work as long as the wiring outside of the reverse loop is done correctly.

The loop itself, if considered in isolation, maintains a propery polarity.  What is crucial is the point where the loop connects back to the rest of the track.

In the red tape example, the turnout at the bottom of the photo must be in phase with the bottom portion of the loop.  The turnout at the top of the photo must be in phase with the top portion of the loop.  Where the two turnouts connect will be the point of reverse polarity.

In the green tape example, the polarities of the two turnouts must match, so the point of reverse polarity is where the top portion of the loop connects to the top turnout.

Hope that all makes sense. Here is a diagram to illustrate.  The black circles are the required rail gaps.  The clear circles are the point of reverse polarity. The rails are represented by red and blue lines.

Rich

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Posted by richhotrain on Tuesday, August 16, 2011 5:23 AM

scookam

Howdy

The other pic is an idea for a yard within the reversing loop. My module is rated for 5 amps and my dcc is prodigy advance rated at 3.5 amps. I'm just wondering if it maybe too much yard for the module to wire all that track to. If I then bought a booster would I wire that to just the reverse loop? Any help, to any of these questions, I would thank you for.

Scookam

 

Maybe Randy or someone can address this issue.

Rich

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Posted by MisterBeasley on Tuesday, August 16, 2011 6:29 PM

The question of "how much power do I need?" is more about the number of engines you're running at one time than about how much track you've got.  I like to do an easy, conservative estimate of 0.5 amps per locomotive, which will cover anything including sound engines with some to spare.  So, your PA should easily handle 7 engines.  Non-sound engines take less power.  Illuminated passenger cars, particularly those with incandescent bulbs, will add to your power needs.

The rating of 5 amps for the auto-reverser is fine.  Your real limit will still be the PA at 3.5.  Unless you've got a very large yard, you probably won't be running more than 1 or 2 switchers, and even with a 3-unit consist in the loop you're still well within the capabilities of the system.

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

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Posted by scookam on Tuesday, August 16, 2011 7:56 PM

Howdy

I wish I had a track plan Johnnny Reb. However, I started this venture by stealing as much room as I could in my house and started cutting wood. No plan I ever made worked out anyway so thank goodness for people willing to lend a hand. 

The question about having enough power in the loop is perfectly clear to me now Mister Beasley. Thank you .

But with isolating the loop I'm not sure Rich. Do I need to gap the track, on the green tape idea, at both ends or will the polarity be the same at the points you highlighted with the clear circles. Sorry again for being so dense.

Scookam

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Posted by floridaflyer on Tuesday, August 16, 2011 8:20 PM

I have my reverse loop is isolated similar to your green setup, only I gaped at the turnouts.  I would move your lower green isolation gap to the divergent track of the turnout, and move the upper green  gap to the connection between the upper turnout and the  regular track. But either way the green method is easier to do and would be effective

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Posted by scookam on Tuesday, August 16, 2011 10:20 PM

I was thinking that way myself floridaflyer. Was also thinking of trying code 55 insolated joiners. Was just going to cut the track after install but this 55 is so delicate I think maybe it would help.As long as there not as large as the code 80 ones I've used on my previous atlas projects. I will order some tonight and find out. Thank you Sir.

Scookam

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Posted by richhotrain on Wednesday, August 17, 2011 4:15 AM

floridaflyer

I have my reverse loop is isolated similar to your green setup, only I gaped at the turnouts.  I would move your lower green isolation gap to the divergent track of the turnout, and move the upper green  gap to the connection between the upper turnout and the  regular track. But either way the green method is easier to do and would be effective

If you do that, then you need to gap the connection between the two turnouts which brings you back to the red tape example.

Rich

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Posted by richhotrain on Wednesday, August 17, 2011 4:21 AM

scookam

But with isolating the loop I'm not sure Rich. Do I need to gap the track, on the green tape idea, at both ends or will the polarity be the same at the points you highlighted with the clear circles. Sorry again for being so dense.

I'm not sure that I understand your question.  In the photo you provided with the red and green tape marks, it is not clear where the upper and lower tracks lead to and what track configuration is beween these two points.  Absent a track plan, can you tell us a little about what the track configuration is to the right of the red and green tape marks.

Rich

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Posted by floridaflyer on Wednesday, August 17, 2011 9:50 AM

richhotrain

 

 floridaflyer:

 

I have my reverse loop is isolated similar to your green setup, only I gaped at the turnouts.  I would move your lower green isolation gap to the divergent track of the turnout, and move the upper green  gap to the connection between the upper turnout and the  regular track. But either way the green method is easier to do and would be effective

 

 

If you do that, then you need to gap the connection between the two turnouts which brings you back to the red tape example.

Rich

Rich, I'm having trouble seeing the polarity switch at the two turnout position, looks like a simple crossover to me but I could be missing something

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Posted by Medina1128 on Wednesday, August 17, 2011 11:21 AM

Get yourself a copy of "Easy Model Railroad Wiring", by Andy Sperandeo. A good bookstore should have it. If not, it's available from the Model Railroading  Kalmbach books online. It makes wiring a reverse loop a snap! I keep my copy on my desk for quick referral. If there's a topic I need in the train room, I just make a copy of the page(s) that I need and take it down with me.

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Posted by scookam on Wednesday, August 17, 2011 11:23 AM

Morning Rich.

The area to the right of these switches is just a loop with a bunch of sidings. The switches in the first picture are just a crossover so I could go eigther way around the loop and to service a yard to the left of the switches. I will take some more pictures and send if that will help. Thanks again.

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Posted by richhotrain on Wednesday, August 17, 2011 3:36 PM

scookam

Morning Rich.

The area to the right of these switches is just a loop with a bunch of sidings. The switches in the first picture are just a crossover so I could go eigther way around the loop and to service a yard to the left of the switches. I will take some more pictures and send if that will help. Thanks again.

In my green tape diagram, if everything to the right of those dark black circles is just a loop with a bunch of sidings, then the wiring on the entire right side of that crossover will be in phase.  Just gap the rails where the black circles (or in your case green tape) are located.

Alton Junction

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Posted by floridaflyer on Wednesday, August 17, 2011 3:56 PM

Rich, I think we are both talking about the same thing, i just moved the green tapes over to the connection of the loop to the turnouts

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Posted by richhotrain on Wednesday, August 17, 2011 5:45 PM

floridaflyer

Rich, I think we are both talking about the same thing, i just moved the green tapes over to the connection of the loop to the turnouts

ahhh, I see what you mean.

Rich

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Posted by scookam on Wednesday, August 17, 2011 10:42 PM

Howdy, again.

I have seen the light regarding this issue. Thank you for having an interest. I just ordered a wiring book, as per Medina 1128 suggested and will try not to bother you all too much in the future.

Thanks,        Scookam

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Posted by richhotrain on Thursday, August 18, 2011 4:18 AM

scookam

Howdy, again.

I have seen the light regarding this issue. Thank you for having an interest. I just ordered a wiring book, as per Medina 1128 suggested and will try not to bother you all too much in the future.

Thanks,        Scookam

Hey, scookam, it's not a bother at all.  Your questions are good and valid.  Keep them coming and we will answer them if we can.

Rich

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Posted by scookam on Thursday, August 18, 2011 10:38 AM

Thanks Rich. As for getting a book on this subject it sounded like a good idea to me. It just might make me a bit more prepared for situations such as this. Any help I can get with wireing has got to be good. Even if I never understand it at least I'll have a picture to look at. Maybe with a finger pointing at the turnout with a caption, insolate the track here dummy! Thanks again.

Scookam

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Posted by Owendubya on Thursday, August 18, 2011 11:22 AM

with all the references we are giving Andy, Linn and the rest, maybe the MR staff in their copious spare time could update some of the classic books. (tongue in cheek)

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