I am new to DCC and I am in the process of building an HO layout using my Bachmann EZ Command system. On the layout I have an up and over that does a half figure 8. When I connect the rails back into the main line, it instantly shorts. I know by tracing the rails that the lines cross(the outside rails become the inside rails…etc). I have tried wiring a jumper and isolating that section of track. As soon as the loco crosses over the isolated connection, it instantly shorts. I have been scratching my head for over a week trying to figure this out. Any help would be greatly appreciated!
You have to gap both rails just before they meet to close the loop you have created. Then, you must wire a toggle switch from your power device, the EZ Command or its bus, but probably only the two wires issuing from it, and then continuing on to just the rails between those gaps…the loop part. The toggle type must be a DPDT, or a double-pole, double throw, and there are wiring diagrammes on the www if you google that term. Relatively inexpensive, but it relies on you to remember to throw the toggle to keep the polarity at either gap correct as the train crosses that gap.
The alternative, as suggested by the person above, is to purchase an automatic one, and the PSX-AR is only one of several types available on the market. I use the PSX-AR, but it costs a pretty penny compared to other types.
FWIW, this isn’t a DCC problem. An unisolated reversing loop will cause a short no matter what type of power supply you are using. Previous suggestions should help you fix this.
To square the circle, in DC you generally use the manual DPDT switch method, although this will also work for DCC. There may be auto-reversers that work with DC, but generally people use the manual switch. There are also issues with direction through the loop when you return to the main in DC that you won’t have with DCC.
With DCC, auto-reversing works great once set-up. I use the PSX-AR, also, very happy with mine. You can also use them to reverse more than one reversing section, so long as you only run a loco through them in one section at a time.