Hi Greg

Finding a short-circuit is sometimes long to find and depends on the type of rail you are using (M-Track, C-Track, K-Track)
Usually, you need to be given a clue so removing all power feeder and plugging them one by one while the power is on will give you a hint on to which zone to look for the short

I have made many mistakes on wiring my layout (approx.70 turnouts, 28 locos) and the best approach I think is:
- to use a thick (2.5 mm²) power feeder cabled in a star arrangement from the CS3 (5A) and all is welded
- at the end of each power feeder line there is a connector to the distribution plate
- from each distribution plate, on wire (0.5 mm²) brings power to a zone where the central conductor is insulated from others
- I used Viessmann distribution plates and this was a mistake because the plugs are popping out all the time. The Märklin ones are far better
- there is no need to insulate the ground distribution, nor to install connectors.

On M track, a simple metal (e.g. a thin wire ) near a metal stud can short. Also a derailing train on a turnout can cause the spring to become red and then totally useless, even cause shorts inside the turnout.
On C track (the best in my opinion) chances or a track-related short are very very small. Rather the risk is that the bridges to cut for creating occupancy zone can accidentally contact
On K Track, the B and O are very close together at the extremity so the risk of short is real and hard to find in concealed road bed.

A funny trick I used in the past is to use car brake lamps in series with each power feeder. Normally, it has a very low resistance but as soon as there is a short the lamp lights up showing which zone is causing trouble

Cheers
Jean

You should tell which rails you using !


But otherwise my suggestion would be:

Think about what you changed before the short circuit happened, and then see if the problem lies there.

If not, you should find out which circuit is causing the short by removing two of them, and then find the one that is the problem.

Then your search starts, but if you have many connections to the underneath wires, then it is difficult, but there must be a the way.

My experience is, that if there is absolute calm in the room, that you can hear a faint ticking, the system shuts down, then find a partner and then look for that way!

Especially with K rails there are tabs that can tease ....

I also know about 24V truck bulbs ( Thanks for that Purellum ), but it is more in the construction phase !

Thanks Fellas for the help. I'm sorry I didn't mention that I'm using C track. I have isolated the problem to one section of the layout which of course is the largest section.

The way to do this is to have a DC power supply that will current limit. Set it up to limit at a lowish current, say a 1/4 to 1/2 amp, and with a sensitive DVM look for the lowest voltage point on the track. You may well need a 4 or 5 digit DVM to find lowest voltage point, but a 3 digit one may get you close enough to find the problem by visual inspection.

You will need to disconnect the boosters and ECoS while you do this.

I've replaced the bus and have connected the drop downs. In doing this exercise, I lifted some track pieces and I found a loose track screw under a track piece. I think the screw moved to one end of the track and this caused the short circuit, as now there's no short. Such a simple thing can cause so much trouble.

Anyway, I'm up and running again with a new bus and wiring system so when (and hopefully it won't happens) happens I can trace the short more easierly.

Regards
Greg

Hi Greg and everybody
When I was using M track often there were shorts as any tiny cable strand / screw / burnt springs inside points/turnouts would cause one and was hard to find.

In this case, the best is to divide your layout into individually powered zone and inserting a 5W car bulb (brake lamp) will turn on and show in which section the short C. is.

Since I am with C Track, the issue is much simpler for me as it is only one of the two:
- a derailled car / train so I look into Rocrail which trains were last running
- a short under the table caused by faulty insulation. Here I soldered all grounds together and protected the non-insulated areas with "Liquid Tape" (a sort of liquid insulator used in boats etc to protect electrical connections

The risk of having a short on the track caused by a metal part is much much smaller
Cheers
Jean