Building a new layout. All track and turnouts are installed and all rail connectors were soldered. At this point no bus wire or feeders have been installed yet.
All Peco turnouts have jumper wires on underside to improve reliability, nothing new for me doing this.
This evening I powered the track just to do test run, well I have a short circuit. i checked no tools etc were laying across the rails. None found. vacuumed the tracks in case of debris.
my layout has no continious loop, just two independent RR’s with an interchange. I disconnected the interchange track so now I have two independent railroads and both have their own short circuit. So clearly I have some type of track arrangement that is causing an issue. I see no reverse loop, double checked and still don’t see one.
I checked several uninstalled turnouts with the jumper wires and none created a short circuit when checked.
Before I start uninstalling all my track I was wondering if there is something else I am overlooking? I plan to disconnect the track leading into the yard and see if I end up with three independent areas each with their own short circuit.
Don’t remove any track but think about isolating smaller sections of trackwork with gaps carefully cut in one or both rails (you don’t mention DCC so if you have DC you can cut one gap in one rail and rely on the other rail as the common) or if using DCC you would isolate both rails to make a “power district” that can have a dedicated circuit breaker protecting each area of trackwork.
Back to those Peco turnouts. Are they a power-routing (Electrofrog) configuration? If so you need to have a rail gap anywhere there is a common rail between two frogs and all feeders have to come from the point side of the turnout.
Quite true, with the turnout sitting by itself. If you place them in a configuration such as in a passing siding where the frogs are joined together by a length of rail, then throw one turnout you will cause your short.
What changed since the last time you powered-up the layout? Are you sure you have feeder wires configured to feed the proper rail? As I was building my layout I placed small stick-on dots (Avery removable stickers) every few feet to designate rail A or B (N or S, whatever designation you want to use).
If you have DC are you going to have block control? You will need isolated rail for that so you will have to have rail gaps anyway. This will help isolate smaller sections of track electrically to make troubleshooting easier.
I’m assuming that you are using Electrofrog turnouts and I suspect that your frogs are not isolated. Study the link that Ed provided to see the proper arrangements:
Is it possible to slide a few of the rail joiners apart so you can isolate (electrically) sections of the layout (or track as laid so far) ?
Much easier to diagnose smaller segments than the whole shebang.
I don’t use Peco turnouts. Is it necessary to add jumpers to maintain continuity?
Is it possible that you tested a turnout and it was OK on the bench but then after installing it the jumpers you installed possibly touched and are now shorted?
Agree with Rich, without some sort of track plan we are guessing. My first action would be to isolate a small section of track close to where you attach the feeders and see if the short still occurs. If so the problem is in the small area of the feeder attachment and the power source. If not keep expanding the isolated section until the short occurs, when it occurs the problem is in the last section that was added to the isolated part of the layout.
All good comments so far. Short circuits can result from a track design problem, or an execution problem. Seeing the track plan and how it is connected to the power source will help the experts here to see if it is a design problem, such as Y or return loop. My bet would be on the execution side - did you recheck all of your wiring to see if the wires are connected at the right place and not touching each other? Do you use a color coding system for your wiring? Breaking down the sections as suggested will help you find the offending section (process of elimination). But a review of your own wiring is probably worth a try before taking things apart.
Forget what I said about the turnouts likely being the problem. I made the assumption that you were using Electrofrogs so nothing that I said applies. The coloured diagram in the link is for an Electrofrog turnout so the parts around the frog don’t apply in your case, and you are already familiar with the jumper placements. I don’t know enough about Insulfrog turnouts to comment on the possibility of them causing shorts. There was a reference in a previous post to shorts occurring if they are used in a reverse loop but that’s not your case.
Testing your track as you go is a very smart move. You don’t have to apply track power to do the testing. All you need is a DC buzzer, a 9 volt battery and a couple of test leads with alligator clips. Wire one leg of the buzzer to one side of the battery (it doesn’t matter which). Wire the other leg of the buzzer to one test lead. Wire the other test lead to the other battery post.
When you are starting to lay track, all you do is connect the circuit across the rails of the first piece of track that you are laying and then proceed to lay more track. If you install a piece of track that causes a short the buzzer will sound immediately and you will know that something is wrong at the exact location where you are working. Leave the buzzer attached all the time.
In your case, the buzzer will come on and stay on until you eliminate the short. The noise could get tiring real fast, so you might want to use an automotive light bulb instead. The only advantage to the buzzer is that you don’t have to look at it to know what’s happening.
You can get a cheap buzzer and the test leads from any electronics supplier. Here is one example of a cheap buzzer:
I might add that most low to mid-range Volt-Ohm-Amp meters have a continuity setting that will beep when there is a short (or continuity). Frequent checking with this “beeper” will indicate when (or if) a short occurs.
Of course, you also have all the other functions of a VOM which will prove invaluable for electrical diagnosis down the road.
if your desperate, try to isolate half of the layout from the other half and see which has the short. Then isolate half of the half until you find the short.
of course, there may be multiple shorts.
and of course it would be nice if the layout were designed with this in mind. So you may have to cut bus wires and reconnect them later.
I really appreciate all the comment, thanks. Let me respond to one or two.
Currently there are no feeders and no buss so therefore no wires have been crossed.
Not sure I can post a track plan, but I was cautious to make sure I had no reversing sections, no Y’s or any other type of section that allows a locomotive to turn around.
so far trouble shooting has involved me dividing the layout into two seperate sections and both independent sections have a short.
I made a mock up between two facing turnouts to create a passing siding and used jumper wires to connect them, no short regardless of turnout position. To me this confirms that insulfrog’s do not need to be gapped because the frog is already insulated.
I now install jumper wires on the Peco’s because over the years I have had a few where the tabs loose contact. Builds in reliability.
i will continue to divide the layout into smaller sections and go from there.
How does a continuity meter show a short? A continuity test simply establishes whether there is an electrical path between two points.
Without a track plan to look at, this is one tough problem. I am trying to visualize a layout with no wiring, no bus, no feeders, no reversing sections or loops. You connect a single pair of wires from the DCC command station, and a short occurs.
When you connect and apply power, is the command station indicating a short? Is there a locomotive somehere on the layout during this test? This is all very weird.
Um, place a probe on rail A, place the second probe on rail B.
No beep, no short.
Lay a 25¢ coin across rail A and B. The meter beeps, you have a short.
That’s how I use the meter anyway.
They are extremely helpful when trying to sort out which side of a wheel/axle is insulated or is your locomotive frame in contact with the left or right rail.
Checking motor/brush isolation before wiring a locomotive for a decoder is another handy use for a beeping continuity meter.
Lots of uses. I also use a continuity meter when wiring up power to a frog using the SPDT switch on a switch machine. I want to be sure the points leading to the frog are at the same continuity that the electrical switch is providing from the common. The meter tells me when I have it correctly wired, no guessing.
Rich, you are correct that I hooked up two wires from my DCC system directly to the rails to test the track. It indicated a short circuit. My multimeter shows continuity between rail A and rail B.
There has to be a track geometry issue but I had though that insulfrog turnouts avoided that issue. Maybe not.
As always time is an issue when it come to reading these posts and getting to apply it to the RR. I hope to get a bit of time over the weekend and do some trouble shooting.
Just to mention, I have visually inspected the track and vacuumed the track for any debris that may have caused the issue. I will run a strong magnet over it too. Who knows. Then I will start dividing the layout to smaller areas.