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Unable to find a DCC wiring short

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Posted by richhotrain on Monday, July 16, 2018 9:27 PM

Too many different color references being thrown around here. So, at the risk of adding even more color references, consider the following. The drawing shows the polarity of the Atlas Custom Line turnout rails as red and blue. To maintain proper polarity, and to avoid a short, the red and blue colored rails should be wired to separate bus wires and never crossed.

Rich

 

Alton Junction

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Posted by maxman on Monday, July 16, 2018 9:09 PM

kasskaboose
While doing wiring, I thought to test if there's still connectivity. Turns out that I have a short. The problem is after checking the common issues--something metal on the track, etc. I know there's one b/c the multimater reads zero while about 12.5 on a test track.

Why are you calling this a short?  If you are reading about 12.5 across the rails of the test track, you must be reading the voltage scale on the meter.  If you are using the same scale setting to check across the rails of the problem area and getting a zero reading, this means there is no potential (voltage) differential between the rails.  So this means to me that either there is no power to either rail, or both rails have the same potential.  If both rails have the same potential, then you will have a short.

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Posted by kasskaboose on Monday, July 16, 2018 9:04 PM

Henry,

Using the picture you sent, I have feeder wires for the mainline.  The feeder for the outside rail on my mainline (which is a black feeder on my layout) goes to the red buss wire (line 2) in the visual.  The inside rail on my mainline (which has a yellow feeder on my layout) goes to the green wire (line 1) on the visual.  Correct?  I think that clarifies things.  Need to walk away before confuse myself!

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Posted by BigDaddy on Monday, July 16, 2018 8:12 PM

Red feeders have to go to the red wire and green to green, if that is what you are asking.

Henry

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Posted by kasskaboose on Monday, July 16, 2018 8:05 PM

Henry,

Thanks greatly for the visual. I need to print it out!.  I think you (and others) hit the issue squarely.  Even funnier is the buss wires shown are exactly what I have, haha!  For the main line feeders, and using the visual, I can then put the feeder for the outside rail on the red wire (line 2) and the inside rail on the green wire (line 1).  Correct?

and answer about doing the wiring in parallel.  Yes, I too only have two hands and like that analogy.  Too funny!

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Posted by BigDaddy on Monday, July 16, 2018 7:24 PM

Lee we are concerned that "outside" might mean the green rail in Track #1 and the red rail in Track #2.  Ignore the fact that the illustration is of a powered frog.

http://help.fast-tracks.net/customer/en/portal/articles/2430158-how-to-wire-a-standard-turnout-with-a-ground-throw-and-how-they-work-

As far as reconnecting feeder to the bus.  If you could hold the feeder parallel to the bus, while holding soldering iron in one had and the solder in the other, that would be fine.  I didn't get that many hands from the factory.  Wrap the feeder around the bus once or twice and solder it, or use suitcase connectors.

Henry

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Posted by richhotrain on Monday, July 16, 2018 6:00 PM

Lee, are you sure that you maintained polarity with the feeders on the turnouts?

When you said that you wired all three outside feeder wires to one of the bus wires and all three inside feeder wires to the the other bus wire, you would create a short since the feeder wires on the divergent side of the turnout would be the opposite polarity of the feeders on the straight through side of the turnout.

What I mean by that is if you joined the outside feeder wire from the divergent side with the outside feeder wires from the straight through side, you have created a short. The matching polarity to the outside rail on the straight through side would be the inside rail on the divergent side , not the outside rail.

Rich

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Posted by kasskaboose on Monday, July 16, 2018 5:15 PM

All,

Thanks for responding to my question.  I plan on approaching the re-wiring slowly.  To clarify,  I have three sets of feeder wires for the turnouts:first set before the switch (one feeder on each track); second set on the diverging track before the frog (one feeder on each rail of the straight tracK); a third set on the straight track (a feeder on each track).  Does that make sense?

Given that others suggest removing feeders from the buss, how to re-solder them?  In other words, should I solder the buss wires perpendicualr to the buss, parallel, or something elese?

Rich: I'm somewhat far along but don't mind redoing if it means getting the wiring correct.

~Lee

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Posted by richhotrain on Monday, July 16, 2018 3:27 PM

BigDaddy
 
kasskaboose
one on the diverging track after the frog and another on the straight track also after the frog? I then take the three outside wires to one feeder and the inside to the other. 

I was going to comment on this but then decided it was just me.  Looks like others may have the same confusion, which may only be semantics. 

Did you mean one set on the diverging track and not one wire?

When I saw outside wires, Ithought outside with repsect to the frog or the middle of the turnout.  I think you meant outside, with respect to a circular or shelf layout.  If you did not, there's the problem 

Henry, once I read your post, I began to wonder if he meant that literally about the outside wires. The outside wire on the divergent rail would be the opposite polarity of the outside wires on the straight through rail.

Rich

Alton Junction

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Posted by BigDaddy on Monday, July 16, 2018 3:22 PM

kasskaboose
one on the diverging track after the frog and another on the straight track also after the frog? I then take the three outside wires to one feeder and the inside to the other.

I was going to comment on this but then decided it was just me.  Looks like others may have the same confusion, which may only be semantics. 

Did you mean one set on the diverging track and not one wire?

When I saw outside wires, I thought outside with repsect to the frog or the middle of the turnout.  I think you meant outside, with respect to a circular or shelf layout.  If you did not, there's the problem

Henry

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Posted by mfm37 on Monday, July 16, 2018 3:11 PM

First thing I would do is disconnect the wire from the frog side of that switch to your bus and see if the short clears up.

Disconnecting the feeder from the bus is your best method. I generally just cut them close to the bus.

 

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Posted by RR_Mel on Monday, July 16, 2018 12:10 PM

Pictures and or drawings really help.  Its tough to explain trouble shooting with out something to go on.
 
 
Mel
 
 
My Model Railroad   
 
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I'm beginning to realize that aging is not for wimps.
 
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Posted by richhotrain on Monday, July 16, 2018 11:51 AM

I think that the OP's question is clear. He is operating in DCC, and the turnout is an Atlas Custom Line. He has wired feeders to all three ends of the turnout.

Lee, it sure sounds like you have crossed at least one pair of feeders. How far along are you with the wiring?

Rich

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Posted by Redvdub1 on Monday, July 16, 2018 11:18 AM

Something doesn't sound right on your wiring description.  You Atlas C83 turnout is an "Insulfrog" with an unpowered metal frog.  What "3 outside wires"?  ...and "one inside wire"?.  Can you elaborate on that commentary?  Your Insulfrog Atlas C83 turnouts have an unpowered metal frog which is "floating" unless you decide to power it via switch machine contacts.  You might check to make sure the frog isolation gaps are not shorted.

 

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Posted by cowman on Monday, July 16, 2018 8:49 AM

Though I haven't done much soldering of feeder wires to track yet, from what I have read, you would be less likely to damage the plastic ties if you disconnect from the buss wire.  They  may be a little harder to reach, but melting only one or two ties could mean track or turnout replacement (not so fun).

Good luck,

Richard

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Posted by BigDaddy on Monday, July 16, 2018 7:30 AM

We don't know how your test track and your layout are wired to your command station.  The first thing I would do is make sure you actually are delivering power from the command station to the mainline.

Divide and conquer as was said.  Do the work where it's easiest for you to tke it appart and put it back together.

Henry

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Posted by gregc on Monday, July 16, 2018 6:44 AM

be methodical, try to isolate the problem

if you added something new and the problem occured, it's most like in your changes.  undo them until you no longer have a short

otherwise, try to isolate the wiring into two halves to determine in which half is the short.  then divide that half in half, ...

greg - Philadelphia & Reading / Reading

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Posted by gary233 on Monday, July 16, 2018 6:40 AM

I’m no expert of solving short problems, just creating them Big Smile.  I’m guessing the experts on this forum will want more info.

DC or DCC, Track plan posted, DCC System if DCC, when where do the shorts occur? Insulfrog or Electrofrog turnouts? Etc.

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Unable to find a DCC wiring short
Posted by kasskaboose on Sunday, July 15, 2018 10:23 PM

While doing wiring, I thought to test if there's still connectivity.  Turns out that I have a short.  The problem is after checking the common issues--something metal on the track, etc.  I know there's one b/c the multimater reads zero while about 12.5 on a test track. 

Nothing stands out as being a cause.  Some questions before removing the feeders:

1. To remove feeders, should I do that from the track/turnouts or from the buss wires?  I would think the track is easier since it's straight metal. 

2. Is the turnout wiring correct for code 83 Atlas custom line turnouts: one set of feeders before the turnout switch, one on the diverging track after the frog and another on the straight track also after the frog?  I then take the three outside wires to one feeder and the inside to the other.  Of course, I am consistent on the colors.

Thanks,

Lee

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