From your description, it does sound like a wheel flange issue rather than a wiring issue or a faulty turnout issue.
What type of turnout is it, and what type of loco is shorting? Or, is more than one loco shorting on this turnout? Where on the turnout is it shorting?
Rich
Alton Junction
PasoTried a couple locos. Short appears to be where the two tracks come to a point but are separated at tip by plastic insert. The are a couple of these on the crossover. X crossover if that is what you meant by turnout type. paso
What type of locos are causing th short? Is every loco causing a short or just some of the locos? Diesels or steam engines? What is the size of the loco? The reason for looking for specifics is that shorter wheelbase locos are more likely to produce visible shorting results than longer wheelbase locos. So, it would helps to have this info.
Regarding turnouts, here is a photo of one:
http://www.walthers.com/exec/productinfo/150-506
If your crossover is a pair of left hand or right hand turnouts, who is the manufacturer (e.g., Atlas, Peco, Walthers Shinohara) and what size (e.g., #4, #6, #8) are the turnouts? This will help others close in on the problem because the shorter turnouts (#4) are more likely to produce shorts with shorter wheelbase locos than longer turnouts (e.g., #8).
My club has the same problem on a couple of Shinohara Electrofrog double crossovers. Nail polish cut down on the occurances. Short four axle diesels make it over ok, but six axle diesels and steam loco's still short out on them. There is a fix that requires cutting gaps in some rails and wiring the frogs to auxiliary contacts on switch machines. Using insulfrog switches would be better.
It sounds like the wiring of the two main lines was not properly connected and they are out of phase. With DCC (and DC too) if the wiring to the two main lines is not of the same polarity you create a short circuit when a train passes from one to the other through a crossover.
The simplest way to determine if this is the problem is to disconnect the DCC system and connect a DC power pack to the layout. Take DC voltage measurements of both main lines near the crossover. If one main lines gives a positive voltage reading but the VOM indicates a negative reading on the other line, the wiring to one of them needs to be reversed all the way around the layout The easiest way to do this would be at the point where the main line wiring connects to the command station.
cacole It sounds like the wiring of the two main lines was not properly connected and they are out of phase. With DCC (and DC too) if the wiring to the two main lines is not of the same polarity you create a short circuit when a train passes from one to the other through a crossover. The simplest way to determine if this is the problem is to disconnect the DCC system and connect a DC power pack to the layout. Take DC voltage measurements of both main lines near the crossover. If one main lines gives a positive voltage reading but the VOM indicates a negative reading on the other line, the wiring to one of them needs to be reversed all the way around the layout The easiest way to do this would be at the point where the main line wiring connects to the command station.
cacole,
Thought about that as a possibility, but wouldn't the DCC system stay shorted (unless there were rail gaps between the connecting rails of the turnout) if the wiring were reversed? On my layout, powered by an NCE DCC PH-Pro 5 amp system, if I mistakenly reverse the wiring, a steady blinking red light on the command station occurs, and no movement takes place unless and until I correct the wiring.
It sounds like his problem is when the wheels of the loco reach the frog.
richhotrain cacole It sounds like the wiring of the two main lines was not properly connected and they are out of phase. With DCC (and DC too) if the wiring to the two main lines is not of the same polarity you create a short circuit when a train passes from one to the other through a crossover. The simplest way to determine if this is the problem is to disconnect the DCC system and connect a DC power pack to the layout. Take DC voltage measurements of both main lines near the crossover. If one main lines gives a positive voltage reading but the VOM indicates a negative reading on the other line, the wiring to one of them needs to be reversed all the way around the layout The easiest way to do this would be at the point where the main line wiring connects to the command station. cacole, Thought about that as a possibility, but wouldn't the DCC system stay shorted (unless there were rail gaps between the connecting rails of the turnout) if the wiring were reversed? On my layout, powered by an NCE DCC PH-Pro 5 amp system, if I mistakenly reverse the wiring, a steady blinking red light on the command station occurs, and no movement takes place unless and until I correct the wiring. It sounds like his problem is when the wheels of the loco reach the frog. Rich
What he is saying is that the are flipped across the crossover. There won't be a dead short to trip your NCE system because the locomotive is completing the circuit when it crosses. Another simple test would be to open the rails on one side of the crossover, beyoond the first set of feeders. Then try flipping the polarity of the feeders and see if the problem goes away.
Engineer Jeff NS Nut Visit my layout at: http://www.thebinks.com/trains/
jbinkley60 richhotrain cacole It sounds like the wiring of the two main lines was not properly connected and they are out of phase. With DCC (and DC too) if the wiring to the two main lines is not of the same polarity you create a short circuit when a train passes from one to the other through a crossover. The simplest way to determine if this is the problem is to disconnect the DCC system and connect a DC power pack to the layout. Take DC voltage measurements of both main lines near the crossover. If one main lines gives a positive voltage reading but the VOM indicates a negative reading on the other line, the wiring to one of them needs to be reversed all the way around the layout The easiest way to do this would be at the point where the main line wiring connects to the command station. cacole, Thought about that as a possibility, but wouldn't the DCC system stay shorted (unless there were rail gaps between the connecting rails of the turnout) if the wiring were reversed? On my layout, powered by an NCE DCC PH-Pro 5 amp system, if I mistakenly reverse the wiring, a steady blinking red light on the command station occurs, and no movement takes place unless and until I correct the wiring. It sounds like his problem is when the wheels of the loco reach the frog. Rich What he is saying is that the are flipped across the crossover. There won't be a dead short to trip your NCE system because the locomotive is completing the circuit when it crosses. Another simple test would be to open the rails on one side of the crossover, beyoond the first set of feeders. Then try flipping the polarity of the feeders and see if the problem goes away.
I must be dense. Is cacole suggesting that all of the feeders are wired correctly except for a pair of feeders where the turnouts meet?
Ahhh, never mind.
I just re-read cacole's response. I see what he is saying.
In any event, we will have to wait to hear back from the original poster to see how he resolved the issue.
That isn't indicated unless the two sections are isolated with gaps in both rails, which the OP did not state. If they ARE isolated the test is easy without disconnecting anything. Use a VOM, or even a 14 volt light bulb and put one lead on each side of the gap on the same rail. There should be no difference in voltage. If the bulb lights, or the VOM shows voltage then it is miswired.
I subscribe to the theory that the back of the wheel is causing a short as it crosses the frog and momentum is carrying it past the short. That, or the frog is insulated and the engine is experiencing no voltage as it passes over it.
Dave
Lackawanna Route of the Phoebe Snow
Thanks everyone for your suggestions.
The last post is what we suspect is happening but the other points raised also provide food for thought.
I'm very tempted to go for the dremel but that's not an option atm with a display next week so looks like avoid using the crossover will be the safer option until after that.
Also a 'guru' on DCC is visiting us shortly and reckons it's an easy fix so I will let you know what happens.
Thanks again.
You still haven't mentioned what manufacturer of the switches (Atlas, Peco, Shinohara, Kato) or the type and # (insulfrog, electrofrog, #4, #6). It would help if we knew.
If it's a miss wired turnout, you don't need a DCC guru to find it. That would short out on DC too. If it works on DC, have another look at the wheel flange and truck gauge. Especially if they are PECO switches.
richhotrain From your description, it does sound like a wheel flange issue rather than a wiring issue or a faulty turnout issue. What type of turnout is it, and what type of loco is shorting? Or, is more than one loco shorting on this turnout? Where on the turnout is it shorting? Rich
I'm standing by my May 8 supposition that it is the wheel flange rather than a wiring issue or fault turnout issue.
Should be interesting to learn the final outcome of this now month-long issue.
richhotrain richhotrain From your description, it does sound like a wheel flange issue rather than a wiring issue or a faulty turnout issue. What type of turnout is it, and what type of loco is shorting? Or, is more than one loco shorting on this turnout? Where on the turnout is it shorting? Rich I'm standing by my May 8 supposition that it is the wheel flange rather than a wiring issue or fault turnout issue. Should be interesting to learn the final outcome of this now month-long issue. Rich
Either this will remain a mystery or maybe the problem remains unresolved.