My apologies if this subject has been covered and recovered - I did look.
This is my first complete layout (n-scale) using DCC from the ground up and I am attempting to wire reversing loops. At first I installed a PM-42 using separate power supply and found that the locomotive used for testing this would cross the double gapped rails and stop. In all cases power was still on to the reversing section and in most cases, power to the booster would not shut down. This was true in all three reversing loops that I wired in.
I checked the gap on the rails and confirmed that power is being delivered to the reversing section. Next I tried taking out the PM-42 and installing an AR-1 to just one reverse section and had the same results. The AR-1 was run off of track power and delivered slightly lower voltage to the rails in the reverse section.
Is there something basic, or not so basic - that I am overlooking?
It sounds like the PM 42 may not be programed or wired for reversing functions. The PM 42 will not only auto reverse but will create power districts as well, but it needs to be programed and wired acordingly. The instructions that came with my PM42 did not tell me about how to install it completly they were more of a getting started instruction set. http://www.digitrax.com/ftp/pm42manual.pdf is a link to the online manual that will give better programing and wiring istructions. I hope this helps! [8D]
Do you have the reversing section gapped in TWO places? You need two sets of gaps and all power feeds to the isolated section have to be from the AR1 or the section of the PM42 set for auto-reverse. Unless there is no way two trains couldn’t occupy two different reverse sections at the same time, they should each have their own auto-reverse, not share one.
I found that the PM42 needed to be set for an amperage that was less than the booster being used. The DB150 is 5amps, the PM42 should have been factory set to 3.5 amps (as I remember the setting) but I found mine set at 12 amps and this gave me similar problems until I reset it. If you have a Zepher unit the amps need to be set at the lowest value - special instructions on Digitrax website.
You also have to ensure the ground wire is connected to the booster
and
Ensure the PM42 is set for reverse operation on the section wired. This too is an internal setting programed by your cab unit as the amp setting.
Thanks to all – I have apparently found the problem. Both the PM-42 and the AR-1 require a feed from the A and B rails. I had a 0.5 volt differential between the A and B side (apparently due to an inferior suitcase connector). Once I replaced the feed wire, it all works.