I run a DCC layout with two power districts. Within the second district I have a short line which branches of the main line. This morning I completed laying the track for a siding on the short line. At either end of the siding is a Peco power routing, insulated frog turnout. On the siding track I installed two #4 Atlas turnouts facing in opposite directions for spur tracks that will be added later. #6 is the minimum turnout I use on my mainline but my short line runs smaller equipment and I will go with #4s as needed. The Atlas #4 has an insulated frog but unlike the larger turnouts, it is completely plastic.
I was testing out the tracks with several pieces of equipment when the Ten Wheeler stalled out on the main track and wouldn't budge. The sound continued but it was just the idling sound and it wouldn't respond to the throttle. I gave it several pushes to try to get it going but still nothing. As I was doing this I got a whiff of what smelled like melting plastic. A few seconds later, I saw smoke rising from the plastic frog on one of the Atlas #4 turnouts and saw the frog was melting. I immediately shut down.
The first thing I did was double check the feeder wires to make sure I hadn't crossed them. I hadn't. The Peco power routing turnout at one end was pointed to the main track and on the other, the power routing turnout was pointed to the siding. Since the polarity for both tracks is the same, I don't see how that would have been a problem.
I am unable to see anything wrong with how I have the tracks aligned and wired. I'm suspecting the turnout that melted might be defective although if the frog was shorting out, shouldn't that have tripped the shutoff for the power district. One other thing I noticed is the tracks connecting to the melting frog were hot to touch. Too hot to keep my finger on for more than a second but the farther I got from the turnout, the cooler the track became.
Has anyone had a faulty Atlas turnout like this or is there something I might be overlooking. One other idea I just got as I'm typing this. Do Peco insulated frog turnouts need to have insulated joiners at the diverging end the way turnouts with powered frogs have to have?
I think your idea about the Peco power-routing turnout is correct. If you power a frog, the power must toggle with the turnout. If you connect fixed wired tracks to the two divergent routes, they must also be flipped or they must be insulated.
It takes an iron man to play with a toy iron horse.
I'm trying to understand this. The frog is insulated. I understand that with uninsulated frogs, you have to be able to change the polarity of the frog depending on which route the turnout is set to. What is different about a power routing turnout that would require insulating the joiners at the diverging end. I thought the whole purpose of an insulated frog was so you didn't have to be concerned with polarity.
The Peco Insulfrog is power routing, a holdover from the days of yore where you could drive a locomotive onto a siding, throw the switch and not worry about it moving until you realigned the switch for the siding.
The issue you have is shorting caused by the wheels...
Peco Insulfrog
The frog rails, of the insulfrog are close together and a site of shorting, therefore the need for insulating rail joiners on the frog rails.
I don't know why the melting would occur at the Atlas frog. Sounds like you could use a circuit breaker though.
Henry
COB Potomac & Northern
Shenandoah Valley
The melted frog is because of the resistance of the short at the frog. Even if it is plastic, the frog rails do come very close. if not put into the frog right they can touch. Solution those two rails should have insulating jointers put on.
Shane
A pessimist sees a dark tunnel
An optimist sees the light at the end of the tunnel
A realist sees a frieght train
An engineer sees three idiots standing on the tracks stairing blankly in space
So it sounds like there's probably a tiny short inside the frog, where the two rails of opposite polarity cross... the result is that some current passes through the high resistance short, creating the heat. Try checking with a multimeter to measure resistance across the turnout's rails (with no locos or command station attached, obviously). Ideally take the turnout out of the layout entirely, if that's easy to do.
Assuming this is the problem, I don't think insulating joiners would help, because you'd have to insulate the entire turnout and then you have a 9" dead spot.
IMO easiest solution is to use a Dremel to cut through the straight rail at the points where it enters and exits the frog. Thus, no opposite polarity signal inside the frog. Then you'd just need to make sure that both ends of the turnout are powered, though, since the frog is no longer letting the straight rail signal through.
As an aside, if it has a plastic frog, I don't think it's a #4? Unless something has changed at the Atlas factory in the last couple years. All my #4s have metal frogs, painted black, insulated from the rails but powerable. My only plastic frogged switches are the 18" and 22" snap switches.
speedybee So it sounds like there's probably a tiny short inside the frog, where the two rails of opposite polarity cross... the result is that some current passes through the high resistance short, creating the heat. Try checking with a multimeter to measure resistance across the turnout's rails (with no locos or command station attached, obviously). Ideally take the turnout out of the layout entirely, if that's easy to do. Assuming this is the problem, I don't think insulating joiners would help, because you'd have to insulate the entire turnout and then you have a 9" dead spot. IMO easiest solution is to use a Dremel to cut through the straight rail at the points where it enters and exits the frog. Thus, no opposite polarity signal inside the frog. Then you'd just need to make sure that both ends of the turnout are powered, though, since the frog is no longer letting the straight rail signal through. As an aside, if it has a plastic frog, I don't think it's a #4? Unless something has changed at the Atlas factory in the last couple years. All my #4s have metal frogs, painted black, insulated from the rails but powerable. My only plastic frogged switches are the 18" and 22" snap switches.
I agree with your assessment for several reasons. One is that the plastic frog on the Atlas turnout aligns with the outside rail of the curved Peco turnout so there should be no polarity issue with the Peco turnout. When the problem occured, the Peco turnout was aligned with the other track so it would not have been passing current to the siding track where the melted frog was. I built that end of the siding first and had no problems until I enclosed the other end of the siding and attached the feeder wires. That's when the issue arose. The heat point was at the frog of the Atas turnout. There is a short piece of straight track between the Peco and Atlas turnouts and if the short had been coming from the Peco turnout, it seems to me the heat would have melted the plastic ties on section of track as well.
At this point, I have no choice but to replace the faulty Atlas turnout. The plastic frog is too misshapen to work correctly. It would be more trouble than it is worth to try to reshape it so it will function, even if I could correct the problem with the rails leading to it. I was surprised when I saw the frogs were completely plastic because I had never seen that on an Atlas turnout before. I purchased these within the last year and I'm wondering if that is a design change by Atlas. Maybe I did purchase a snap switch inadvertently. My guess is this plastic frog did not seperate the two rails leading to it as it was supposed to do and that caused the short. Once I remove this turnout, I'm going to turn it over and try to confirm what I believe.
John, I agree that the fault lies in a defect in your Atlas turnout. My layout is built exclusively with Peco Insulfrog turnouts, and I have several sidings like yours, including having feeders in the siding. I pull trains in/out of the sidings all the time with only one turnout aligned to the siding. There are no issues.
Unless they've changed their design since I last used them, the jumpers on Atlas turnouts are not visible as they are hidden by the tie structure of the turnout. My guess is something went slightly wrong when that particular turnout was built, creating a high resistance short as Speedybee indicated. Would explain your issue perfectly.
The potential shorting issue on a Peco Insulfrog that keeps being brought up happens when rolling stock wheels bridge the diverging rails. You indicated your loco was out on the mainline suggesting you were not at one of these turnouts. As your Peco turnouts didn't melt, that's yet another indicator that they are not the problem. An easy tell would be to remove your damaged Atlas turnout and replace it with a piece of straight track. No issues=your Atlas turnout is the entirety of the problem.
Mike
Water Level Route An easy tell would be to remove your damaged Atlas turnout and replace it with a piece of straight track. No issues=your Atlas turnout is the entirety of the problem.
An easy tell would be to remove your damaged Atlas turnout and replace it with a piece of straight track. No issues=your Atlas turnout is the entirety of the problem.
That's an excellent short term suggestion since I won't be building that spur track off the Atlas turnout for some time. It should confirm what I suspected from the beginning, that the problem is a faulty Atlas turnout frog and not an issue with the way I installed the Peco turnouts. Once I take out the Atlas turnout, I'm going to remove the plastic from the frog and see if the two rails are touching.
Whiskers, happened to me after a short once, a female dog to fiqure what was wrong at first.
Lastspikemike Having also purchased snap switches not knowing how different they are to Code 83 numbered switches I recommend you don't buy them. The Atlas numbered turnouts look and work much better. Snap switches are designed to fit into sectional track layouts. The 22" models even come with short curved sections to fit to the diverging route if memory serves.
Having also purchased snap switches not knowing how different they are to Code 83 numbered switches I recommend you don't buy them. The Atlas numbered turnouts look and work much better.
Snap switches are designed to fit into sectional track layouts. The 22" models even come with short curved sections to fit to the diverging route if memory serves.
As it turns out, these are snap switches. I think I purchased them from Amazon last year and apparently I did not read the description close enough. I have two other #4 switches still in the packaging which I bought from my LHS and it has insulated metal frogs. Live and learn. I installed a left and a right on opposite sides of the curved siding. The left hand one seems to be working OK. I've removed the right hand one but haven't removed the plastic around the frog rails yet to confirm if there is some contact. I'm working on another issue right now.