ISOLATING CROSS-OVER IN A LOOP

[carpediem4570]

ISOLATING CROSS-OVER IN A LOOP

Greetings One and All:

We have some progress with a few minor changes to the track plan.  I’ve include a cross-over reverse on a loop.

I need advice on track isolation.

In the photo, I have marked the track in the affected area with red for positive and black for negative. 

The areas circled in blue is where the positive and negative reverse when connecting to the loop.  The exception is the cross in the middle.  I circled this because I am wondering if this cross needs to be isolated separately.

The four areas highlighted in green are where I think I need to isolate the track from the loop with plastic fishplates.   Can I use plastic on just one rail; red or black or, do both rails need to be isolated?

I have two auto reverse, (ar), units.  Can I use one ar for the entire cross-over  or do I need one ar for each leg?

Your help as always, is appreciated.

Kind regards,
Max

[carpediem4570]

All righty then:

Got the track laid on the three ovals and the reverse loop section.  To test the track for problems, I ran my dc locomotive and cars. 

I isolated the four directions of the cross in the reverse loop with plastic fish plate.

Had a dead spot on the cross and once across that, the locomotive reversed direction.  Who knew, lol.

Switching direction on my power pack allowed me to go on my merry way.

Wiring this for railpro, I will install my auto reverse units.  I still have to figure out how to do that.  Do I need one or two auto reverse units?  Will I have to rewire the cross with jumper lines?  Where do I isolate the track?

Well, it’s a learning curve.  A pleasant one.  Glad I’m retired, lol.

The red arrow points to the cross.  The blue lines show where I used plastic fish plates.

Kind regards,

Max

[G8B4Life]

Yes, you will need two AR-1's, one for each leg of the cross.

You have put the insulated (plastic) joiners in the wrong spot, they really need to be where you have put the green lines in your first pic, just after each turnout (while what you have done would technically work the length of track to auto-reverse in is realistically too short to to work well). As these legs are quite short you need to be sure that you don't bridge the insulated joins at each end of a leg at the same time with something that conducts, like and engine or something with wheel wipers or you will get a short.

- Tim

[carpediem4570]

Thank you Tim for your advice.

My plan is to put the plastic joiners where the green lines are, in picture one.

Is there any place in particular where the ar’s should be attached to the track?

Do I have To do anything to the cross to isolate the north-south from the east-west or it it already isolated?

Thanks again for the advice.

[G8B4Life]

I don't know what brand of track your using but zooming in on that 90 degree crossing it appears each leg of the crossing is well and truly isolated from each other.

There isn't anywhere particularly special that the AR-1's should be attached to, as long as they are powering the correct piece of track. Using your first pic as an example, for the BL-TR (Bottom Left - Top Right) leg I'd attach an AR-1 roughly where the tape measure is. For the TL-BR leg I'd do the same thing, mirror image of the first (this is based on the legs being isolated with the plastic joiners at the green lines). Then the AR-1 are powered (input) by what ever is powering the inside track loop, and the output of the AR-1's power the legs of the cross.

- Tim