# Do i need these insulated joiners here



## irontodd (Aug 28, 2014)

So i put these insulated joiners in place to prevent a short, this is configured for dc only at this point. The 2 tracks are opposing polarity, i.e. both outside rails are positive and the rails closest to each other are negative. I was thinking i needed them to prevent accidental short until i go dcc and match their polarity. Right now i have the turnouts disabled, meaning the movable points are tacked so trains cannot diverge/cross over to the neighboring track. I put the joiner in for a little extra insurance against shorts. But then i thought about it, these are atlas switches with insulated frogs. So i think i have a dead length of rail between the frog and the insulated joiner. Electrically speaking, would a standard metal joiner be the right thing to use here, both now for dc isolation and also for DCC once i get there?


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## Lemonhawk (Sep 24, 2013)

I would check the continuity from the point rail to the exiting frog rail and I think that you will find that there are jumpers from the appropriate point rail to the appropriate exiting frog rail. If so then you are OK with the insulated joiners although on DCC they may not be necessary. They would be necessary on DC if you have the loops separately controlled, then you'll get a short if the loops are going in different direction.  I think these switches can be used to remove power from a siding based on point contact. But check the continuity of a switch you have yet to use just to make sure the point are power routing. If not then you may have a dead rails and you will need to wire in drops to the exiting frog.


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## MtRR75 (Nov 27, 2013)

irontodd said:


> The 2 tracks are opposing polarity, i.e. both outside rails are positive and the rails closest to each other are negative. I was thinking i needed them to prevent accidental short


The two tracks will definitely short out without the insulated joiner.

But there are bigger issues here. Normally when two tracks are parallel, they are wired the same -- meaning both outside rails are positive and bot inside rails are negative (or vice versa).

...Unless one of these two tracks is part of a reversing loop. The reversing loop will have a directional switch that allows you to reverse the polarity when necessary. If that is case, your situation is normal.

Do you have a diagram of your layout that we can look at?


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## DonR (Oct 18, 2012)

Yes, as Lemonhawk says, the joiners are correct as you
have them considering that the DC polarity is reversed in
the two tracks. You could actually move a DC train from one
oval to the other simply by using the 'reverse' switch on
ONE power pack to match the polarity of the other.

If the two tracks joined by the crossover are
basically two separate ovals then the joiners would not
be required when you go DCC. However there would
actually be no reason to remove them. 

Don


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## irontodd (Aug 28, 2014)

Thanks for your input guys. MtRR, I do have a reversing loop situation, but not at this location, and not at this time. The neighboring tracks you see here are effectively 2 sides of a single oval. I have tacked (with a track nail) both turnouts involved so that until I get all the dcc stuff I will not be able to transition across this crossover. 

As lemon hawk suggested, I confirmed continuity to both rails of the diverging route, so I will keep the insulating joiners in for now. 

Sent from my SM-T550 using Tapatalk


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## Mark R. (Jan 26, 2013)

irontodd said:


> Thanks for your input guys. MtRR, I do have a reversing loop situation, but not at this location, and not at this time. The neighboring tracks you see here are effectively 2 sides of a single oval. I have tacked (with a track nail) both turnouts involved so that until I get all the dcc stuff I will not be able to transition across this crossover.
> 
> As lemon hawk suggested, I confirmed continuity to both rails of the diverging route, so I will keep the insulating joiners in for now.
> 
> Sent from my SM-T550 using Tapatalk


Adding DCC isn't going to negate the need to keep those two tracks of opposite polarity separate from each other. DC or DCC, you will still get a short. You are going to need an isolated section at some point in order to change the polarity of the mismatched mains if you are ever planning on actually using that cross-over. 

Mark.


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## irontodd (Aug 28, 2014)

Mark R. said:


> Adding DCC isn't going to negate the need to keep those two tracks of opposite polarity separate from each other. DC or DCC, you will still get a short. You are going to need an isolated section at some point in order to change the polarity of the mismatched mains if you are ever planning on actually using that cross-over.
> 
> Mark.


Thanks Mark. Once I get to dcc the tracks here will be parallel polarity, and the balloon ends of the Oval will be auto reversing sections (long enough to hold my mongers lighted or double ended consist). Lots of temporary measures right now so I can test the track work on DC.

Eastern Plains - Holyoke, Idalia and Towner (EPHIT) Branch build thread http://www.modeltrainforum.com/showthread.php?t=102266


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## MtRR75 (Nov 27, 2013)

irontodd said:


> I do have a reversing loop situation, but not at this location, and not at this time. The neighboring tracks you see here are effectively 2 sides of a single oval. I have tacked (with a track nail) both turnouts involved so that until I get all the dcc stuff I will not be able to transition across this crossover.


OK, now I understand the opposite polarities of the two tracks. But this means that the crossover between the two tracks establishes a reversing loop. However, since you have insulated the tracks and tacked the turnouts so that no train can cross at this point, you have negated the reversing loop -- for now. But I assume that you have plans for this crossover. Just remember that activating it creates a reversing loop.


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## irontodd (Aug 28, 2014)

Yep once i go dcc it will be pretty much this scenario (image from wiringfordcc.com)

http://www.wiringfordcc.com/dogbone_end_ARSC.gif


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## Lemonhawk (Sep 24, 2013)

And now that I see where the turnout is the big picture, you definitely need the insulated joiners. Actually if your unsure if insulated joiners are needed, its best to put them in. You can always just add another drop and sometimes its nice when your trying to isolate a track problem to isolate things to a smaller section. Just try to keep them away from any curves!


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## DonR (Oct 18, 2012)

Irontod

Now that you used the Wiring for DCC drawing
There are big changes in my previous suggestions.

Here on the Form, we have had 2 or 3 very similar
'reverse' loop
situations like yours, where you install a crossover
between the 'east bound' and 'west bound' tracks.

The simple solution is to remove the insulated joiners
from between the two turnouts. Wire BOTH east
and west tracks with right rail RED wire, left rail BLACK wire.
Therefore, there is no short when locos move from one
track to the other. 

Then install an isolated section in each end loop.

It will require two reverse loop controllers. However,
you might look at the Digitrax PM42, a device with
4 reverse controllers that can also be used a
short circuit protection for track blocks.

The reason for this unusual track wiring is that
crossovers are mainly intended to make movement
from one parallel track to another thus the two right
rails would be Red. Thus you must do the same.

Don


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