DCC turnout wiring question

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Question on DCC wiring. I have a loop, with a spur to the inside. I have a switcher on the spur, and a loco running around the main loop. When I throw the spur switch (I’m using a Peco insulfrog turnout), I can pull the loco onto the spur with no problem, at which time the switcher also runs. But when I return the loco to the main loop, and throw the switch so it runs continually around the loop, there seems to be no power to the spur and the switcher doesn’t run. Do I need to run a power line to the spur as well as the main loop? Or do I need a different kind of turnout?


Well-Known Member
The turnout you are using must not be power-routing or it is defective if it is supposed to be power-routing. Peco Code 83 Insulfrog turnouts are power routing. If your switcher doesn't run unless the diverging route is selected on that one spur turnout, the turnout you have that allows access to the spur inside the loop is either defective or it is not of the power-routing type. Get another or repair the one you have if it can be repaired. Alternatively, you could just drop a pair of feeders to the switcher's track.


Section Hand

Like Selector suggested, add a pair of feeder wires in front of the turnout on the diverting route to solve your problem. Had a similar problem on my layout when I forgot to attached a pair of feeder wires to the bus wiring. Be sure you keep the feeder polarity the same on the spur and the mainline.

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The PECO turnouts are power routed but through the points. I have found that this is not a reliable method so always put feeders on the diverging side of the turnout.
One cheat I've done is to solder wires to a pair of rail joiners from each outer rails to the rails past the frog. This way the rails past the frog are always powered and I can use the turnout just like an Atlas turnout for quick layouts (just connecting track pieces together).
Good thoughts, thanks. But why not just use a Peco electrofrog turnout (instead of an insulfrog)? Wouldn't that result in the siding always being powered?


Section Hand

Yes, a power routing turnout would work just fine, however, adding feeders beyond the turnout is always a recommended practice to insure electrical feeds to the trackage.



Iron Horseman

Well-Known Member
But why not just use a Peco electrofrog turnout (instead of an insulfrog)? Wouldn't that result in the siding always being powered?
No it would not. Whether the frog is hot or not is an independent variable from whether the departing tracks are powered through the points (power routing). With an electrofrog turnout the siding will still be dead when the track is switched to the main (because both rails will be the same "polarity"). To get the siding powered all the time requires a feeder wire to it. The difference is that with an electrofrog one would also need an insulated rail joiner or a gap in the rail between the feeder and the frog, while an insulfrog does not need this gap. The insulated frog is the gap.
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Got it . . . did some research and came to the same conclusion. So the simple answer is to use the Peco insulfrog turnouts, as I'm doing, but add feeders beyond every turnout. Thanks to all for your responses and suggestions.

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