How to wire the

DCC Specialties PSX-AR Auto Reverser

to work with Peco Electrofrog Turnouts using snap-coil motors

According to the DCC Specialties manual (Manual Rev: 0 10116) (Software Rev: N 4115): The PSX-AR Series is a Intelligent, DCC, Solid State Circuit Breaker and Auto Reverser with Integrated Control for Stall Motor Switch Machines for Loop Automation. And a fine job it does switching a Circuitron Tortoise Switch Machine.

However DCC Specialties also offer a version, called a PSX-ARSC, which is marketed as working with snap coil switch motors, such as the Peco PL-10. What DCC Specialties do not tell you is that, out of the box, without any special wiring the PSX-ARSC will only work with Atlas or Peco Insulfrog turnouts. It fails totally to move a switch motor attached to a Peco Electrofrog turnout.

According to richhotrain, writing on the web site:

“With regard to the Peco Electrofrog, the issue is attributable to both the powered frog and the power routing feature of the turnout.  As a result, the inner frog rail on the non-selected route has the same polarity as the corresponding stock rail.  Gapping the ends of those rails is apparently not enough to prevent a short when the locomotive exits the loop and the point rails are simultaneously thrown, as a matter of timing, so an extra section of track is needed.”

As Rich comments, the solution is to add two additional sections of track, powered from the track bus, after each leg of the Peco Electrofrog turnout.  The following diagram illustrates the wiring of these two extra sections of track.

Rich explains the purpose of his wiring as follows:

“When the loco proceeds on the straight through route of the turnout, the PSX-ARSC will be unaffected as the loco crosses the gaps into that new track section and remain unaffected as the loco crosses the gaps into the loop.  That is because the turnout, the newly added track section and the loop are wired the same way (the polarities match).  Only when the loco crosses the gaps to exit the loop will the PSX-ARSC be affected since the polarity of the loop will not match the polarity of the newly added track section between the loop and the divergent route of the turnout.”

At this stage you, the reader, may be asking why these additional track sections are needed as surely the switch motor will change it's route when the loco crosses the gap immediately before the turnouts frog. The truth is we are not sure but it appears that the PSX-ARSC needs more time to make the change to the alternative route and the extra track sections provide that time. If the extra track sections are not present the turnout will not change and the Locomotive will stall when it enters the same block as the Peco Electrofrog turnout and not start again until the turnout is manually changed.

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