Hello. I am setting up an around the desk nscale dcc layout using Kato unitrack and a NCE PowerCab. I have two Kato double crossovers currently and I am wondering how to wire the line feeds and where to put the insulators and the PSX-AR auto-reversers. I have attached a rudimentary schematic of the layout where I have dropped line feeders on all of the points of the turnouts and all four points of each double crossover ensuring that the lines each attach to either the red or the black wire using the colored tape on each side of a boxcar method. I have indicated the rail power drops with blue boxes. I am pretty certain on the inner dog-bone loop that I need an auto-reverser (PSX-AR) on each loop, and that I will need to insulate the loops as shown by line cuts with red triangles (I have 2 PSX-ARs from a previous layout). However, I am unclear if I need to insulate part of the outside loop add auto-reversers to it due to the double-crossover connecting the inner and outer loops. I hope that this makes sense while looking at the schematic and I will try and post pictures as well. Thank you all, Spencer
You really only have one reversing loop, if you wire it up as such: The double xovers from Kato are insulated WRT the inner rails at the middle of the xover (visible gaps in all rails midway on the xover, except for the outer rails, which are continuous end-to-end). Thus you should put insulating joiners where you have labeled your inner loop PSXs to go, and remove the others insulating rail joiners. One psxar will power the bottom half of that inner loop. The rest of the trackage (upper half of inner loop, and all of outer loop) need never reverse polarity, and can be connected directly to your CS/booster. You do not need a second psx ar controller anywhere.
I should add that you should never have AR controllers adjacent to each other (where a train can pass over insulated joiners between the two auto-reverse sections.) The two AR controllers will tend to fight against each other, both reversing at the same time, and thus not clearing the short.
Thank you Big Jake! If I understand correctly I will only need one of the AR controllers and power both sides of the double crossover loops from that one controller. I will try that tomorrow and report back with a new schematic of how I did it and how it works. Thank you very much for the assistance, it is much appreciated. Take care, Spencer
Just to be clear, your diagram showed the inner loop divided into two left/right halves. I would divide that inner loop into two upper/lower halves instead. You only need one AR controller, for the lower half of that inner loop. The rest of the layout, including the upper half of the inner loop, can be controlled directly from the command station/booster that powers the AR controller, that in turn powers the lower half of the inner loop.
You need the auto-reversers on the inner loop. For the outside loop, you could put them if you have them, or you could just connect your powered cars via thick stranded wire; this is what I've done on my outside loop. If you have trouble with the thick stranded wires, then you can just do a short run of thick stranded wire that connects to the inner loop, then it will cut off any power from the outside loop, but if you have powered cars on the outside loop that's a bad idea. Anyhow, like I said, if you can use the auto-reversers, use them, but if you don't have them you can get by without them.
Be careful NOT to put two AR controllers on two tracks that are on either side of the same pair of insulated rail joiners (or isolated rail gaps). This can cause both ARs to trip simultaneously (and repeatedly) when shorted, which does not remove the short (it just reverses the 'polarity' of the short).
Thank you BigJake and RudolphJ382 for your comments and advice. I moved the track insulators a bit on the inner loop from where they were before and finished connecting all of the turnout points to the main bus and everything seems to be working really well. The inner loop with the double-crossover in the middle, and the outer loop with the double-crossover that connects the outer loop to the inner loop. I figure with where the insulators are on both dog bones of the inner loop I can run a train with ~15 50" box cars which is max number I would usually run so I think I am ok on those dog bones where the PSX-ARs are connected on the inner loop. I am uploading an updated image of the layout with the correct placement on the insulators t in case someone else can benefit from the information. Thanks again, Spencer
