Author Topic: The Case of the Phantom Short  (Read 1273 times)

ON28

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The Case of the Phantom Short
« on: September 18, 2020, 05:27:02 PM »
Thought I'd pass this on. Was wiring some Atlas snap switches (with plastic frogs) crossover, four wire feeds per switch plus shim brass bus bars from stock rails to closure rails, as well as shim brass under stock rails and points. (A little extra work but works for me.) Anyway, I am testing with an RP+KA diesel to see approximate voltage, and getting a voltage drop moving through the crossover followed by a return to full power after a few seconds All the feeds are good, and the drop only occurred in one direction. Listening, I here a clicking typical of a short. Turns out the metal wheel of one car was bridging the stock rail and wing rail at the open end of the frog. Who knew?

I'll tell you who. By coincidence this past week my knowledgeable train store guy Warren said he had seen this in some higher quality Peco switches, solved by painting the too-close rail tops with insulating clear enamel. I tried this and it worked. Warren said another way to detect a short is to turn out the room lights and look for sparks...

 

Alan

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Re: The Case of the Phantom Short
« Reply #1 on: September 18, 2020, 07:02:32 PM »
I'd listen to Warren.
Alan

LK&O Railroad website

When I was a kid... no wait, I still do that. HO, 28x32, double deck, 1969, RailPro

ON28

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Re: The Case of the Phantom Short
« Reply #2 on: September 19, 2020, 11:20:09 AM »
Warren's the man! The Model Railroad Shop, Dunellen, NJ.