Electrical short - your help is requested!

[StanierBlack5]

Please look at image #02 to see my set up and then image #01 to see where I have a problem that I cannot solve.

When a loco leaves district #1 via the points (using iP Digital point motors) to district #2, when in between the two districts a short occurs, this is my first layout build and I'm learning as I go!

 

Your help in this matter would be very much appreciated.

 

Thanks in advance,

Roger

[Dagworth]

Try putting a wire where either the blue line or green line are here. If this also causes a short then swap the track feed wires over in district #2

 

Andi

[Graham108]

On the assumption the missing sleeper on the very short piece of track between the 2 points is for feeds from underneath the track, check you have these wired the right way round. If you don't have any feeds here then you have a 'dead' section on the lower rail.

[DY444]

I would start with the short (lower) bit of rail with the insulated joiners at each end between the two points where the short circuit is happening. 

 

Where is that bit of rail power fed from?  Looking at the picture it should be the same as the lower rail of district two.  However if you've got it connected to the upper rail feed of district 2 by mistake then you'll get a short every time the loco bridges either of the insulated rail joints at each end of that bit of rail. 

Edited November 7, 2020 by DY444

[Andymsa]

Looking at the placement of rail joiners on the crossover, it appears to have been over complicating by wiring the section of track between cross overs. In essence this is just a cross over with an additional section of track extending the crossover. Simple solution only have one set of insulated rail joiners at one end, the other end make conductive and remove any power feeds to the section of track where the short occurs.

[StanierBlack5]

Firstly, thanks for all your input.

 

I've had a good look underneath the baseboard this morning and the more I look, the more baffled I get!

Working on the 'KISS'  formula and taking on board what you have said, if I remove the short piece of track in question then power the point instead where it joins to the next point, would that work? Please see my diagram. 

 

Once again, thanks in advance,

Roger

 

 

[ITG]

It may be helpful to determine what exactly is meant by ‘short’. Is it possible to say if the problem is a section of track with no power or a section that is the incorrect polarity? In my limited experience, I’d say you have an extra isolating rail joiner which is not necessary, ie the left hand end of the lower rail on the track just above your ‘electrical short occurs here arrow’. Unless that short section of track has a power feed, or such a feed is of the correct polarity, that’s why a loco stops there.

 

is there a feed there? 
Do you have a meter to test power to that section, and to the left and right of it?

 

To answer specifically you question of adding a feed on the last photo, I cannot see that helping if the problem is on the track section as I described above, as your suggested solution is aimed at the wrong rail.

[Pete the Elaner]

4 hours ago, Andymsa said:

Looking at the placement of rail joiners on the crossover, it appears to have been over complicating by wiring the section of track between cross overs. In essence this is just a cross over with an additional section of track extending the crossover. Simple solution only have one set of insulated rail joiners at one end, the other end make conductive and remove any power feeds to the section of track where the short occurs.

 

If you mean reduce insulating rail joiners & feed from points, I disagree.

I have found that feeding sections via points causes lots of issues & can make troubleshooting very difficult.

Isolating after & re-feeding after every point makes problems much easier to find.

[RobinofLoxley]

You have Electrofrog points. Have you complied with the recommendations for the wiring of these points? There are many threads where its discussed but i cant point you to one as they aren't that obvious.

 

What kind of loco is causing the short, in other words where is the rest of the loco at the point where the short is.

 

District 1 would not seem to be involved as the loco hasn't reached it in an electrical sense, from what you have told us.

 

There is what looks like a small piece of wire running across the switch rails, which are of opposite polarity. One or other rail may be dead depending on the point position and the rest of the track wiring. is it real or just a piece of hair?

 

Based on what we can see, the small section of track between the two points needs a power feed on one side only, as the other side in theory is getting power through the metal fishplate connection to the stock rail of the point. If that is how its wired, is that particular piece of track (the isolated side) powered from the correct side of the DCC bus?

 

 

[Edward]

Just remove one of the 2 insulating rail joiners on the left lower rail.

If the upper point is set against that road,  the loco will stop (which is what you want ). 

Change the point and the loco should start.

If there is another short ( when light goes out on power panel) swap the track feeds over on your Cobalt.

 

[Andymsa]

4 hours ago, Pete the Elaner said:

 

If you mean reduce insulating rail joiners & feed from points, I disagree.

I have found that feeding sections via points causes lots of issues & can make troubleshooting very difficult.

Isolating after & re-feeding after every point makes problems much easier to find.

The method you describe can be as problematic, having a small 2inch section having its own power feeds is just making more work adding that wiring. As the OP has found it can lead to such issues as a short by not keeping things simple. Just soldering the rail joiners will resolve such issues as power reliability. Having around 300 points on my layout I have not had any issues with power routing through points.

[Pete the Elaner]

3 hours ago, Andymsa said:

The method you describe can be as problematic, having a small 2inch section having its own power feeds is just making more work adding that wiring. As the OP has found it can lead to such issues as a short by not keeping things simple. Just soldering the rail joiners will resolve such issues as power reliability. Having around 300 points on my layout I have not had any issues with power routing through points.

 

I agree that small sections is more wiring.

If you really do have 300 points & you've used them to carry power to the following sections then you've been very fortunate to have a working layout at all.

 

But everything else you've said is wrong.

 

Small sections can be electrically joined below the board & if you have caused a short by connecting something wrong, just snip the offending wire.

Big sections cannot be split without lifting the track so if there is an issue, resolving it can be a major headache.

Therefore small sections are less problematic than larger ones.

I have been asked numerous times to look at layout shorts & these are invariably caused by loops fed from the wrong end because the sections are too big. I make it the layout owner's job to lift the track.

I used to use larger electrical sections but learned through experience that smaller ones are much easier to work with. I didn't just make a random decision that small sections is a better way to work.

 

Soldering rails together opens up the issue of expansion & contraction in heat. I doubted this would really be enough to cause a problem until someone pointed me to an online calculator to calculate the deflection of a curve & I looked up the expansion coefficient of Nickel Silver. I can't remember the maths for this now but do remember being surprised at how much deflection a change of 10c can cause over a metre. If it contracts, the solder joint will simply break, which defeats the object of soldering it in the first place.

 

Have you got a layout thread please? Something with 300 points is worth a look.

[newbryford]

Shouldn't there be an insulating joiner on both vee-ends of the upper left point?

 

 

 

 

[Andymsa]

46 minutes ago, Pete the Elaner said:

 

I agree that small sections is more wiring.

If you really do have 300 points & you've used them to carry power to the following sections then you've been very fortunate to have a working layout at all.

 

But everything else you've said is wrong.

 

Small sections can be electrically joined below the board & if you have caused a short by connecting something wrong, just snip the offending wire.

Big sections cannot be split without lifting the track so if there is an issue, resolving it can be a major headache.

Therefore small sections are less problematic than larger ones.

I have been asked numerous times to look at layout shorts & these are invariably caused by loops fed from the wrong end because the sections are too big. I make it the layout owner's job to lift the track.

I used to use larger electrical sections but learned through experience that smaller ones are much easier to work with. I didn't just make a random decision that small sections is a better way to work.

 

Soldering rails together opens up the issue of expansion & contraction in heat. I doubted this would really be enough to cause a problem until someone pointed me to an online calculator to calculate the deflection of a curve & I looked up the expansion coefficient of Nickel Silver. I can't remember the maths for this now but do remember being surprised at how much deflection a change of 10c can cause over a metre. If it contracts, the solder joint will simply break, which defeats the object of soldering it in the first place.

 

Have you got a layout thread please? Something with 300 points is worth a look.

yes I really do have that number of points, but I’m in the midst of a major layout change so the number may reduce a bit but will still have around 270 of them. The reason I don’t have issues is testing testing testing, I’m not sure why track lifting would be required to resolve a short, but good design of the placement of feeders and isolation joints would resolve many issues. But any new track is tested before any ballast laying is done or any soldering is done in any case. When I lay track I use coloured pins red a white to denote track polarity. I don’t have massive long soldered sections in any case as I have track detection and the isolation between sections is used for track expansion but it’s not a big issue in any case as the room is temperature controlled. Unfortunately I don’t have a layout thread and I really don’t know how to start to describe things.

[Pete the Elaner]

2 minutes ago, Andymsa said:

yes I really do have that number of points, but I’m in the midst of a major layout change so the number may reduce a bit but will still have around 270 of them. The reason I don’t have issues is testing testing testing, I’m not sure why track lifting would be required to resolve a short, but good design of the placement of feeders and isolation joints would resolve many issues. But any new track is tested before any ballast laying is done or any soldering is done in any case. When I lay track I use coloured pins red a white to denote track polarity. I don’t have massive long soldered sections in any case as I have track detection and the isolation between sections is used for track expansion but it’s not a big issue in any case as the room is temperature controlled. Unfortunately I don’t have a layout thread and I really don’t know how to start to describe things.

 

Are you serious?

[kevinlms]

18 hours ago, StanierBlack5 said:

Firstly, thanks for all your input.

 

I've had a good look underneath the baseboard this morning and the more I look, the more baffled I get!

Working on the 'KISS'  formula and taking on board what you have said, if I remove the short piece of track in question then power the point instead where it joins to the next point, would that work? Please see my diagram. 

 

Once again, thanks in advance,

Roger

 

 

Not sure that removing a small piece of track is going to make the slightest difference.

The way you have described the fault occurrence, is when you attempt to run a train through it. That indicates that the 2 wires feeding it are reversed. The wires should of course come from District #2 and NEVER District $1.

[RobinofLoxley]

Sorry about going off topic, but I am bewildered by this risk of exansion thing. I suppose people have experienced it. I have a layout in an uninsulated loft it gets up to 40C on the hottest sunny days, and probably 5C on cold winter nights - goes without saying the insulation on the loft floor is pretty good. I haven't noticed a problem with expansion, and this was my DC layout with few breaks in the track. What I didnt do is lay the track so as to leave zero gap between each rail, I always left a small expansion gap where I could and relied mainly on the fishplate to carry the power. By small I mean just visible, less than 1mm. As I am converting to DCC and have lifted all the track, I wont be relying much on fishplates but I will have a lot of insulated joiners. These are quite soft plastic and if laid with that same approach, Im not expecting any trouble from them. The plastic is fairly soft and would compress very slightly under pressure in the worst case. The longest gap between IRJ's is likely to be the full length of a piece of flexi, so just under a metre.

[Andymsa]

9 hours ago, Pete the Elaner said:

 

Are you serious?

the whole sentence needs to be read regarding the statement not just one part of it. I guess we will have to agree to disagree.

[DY444]

21 hours ago, StanierBlack5 said:

Firstly, thanks for all your input.

 

I've had a good look underneath the baseboard this morning and the more I look, the more baffled I get!

Working on the 'KISS'  formula and taking on board what you have said, if I remove the short piece of track in question then power the point instead where it joins to the next point, would that work? Please see my diagram. 

 

Once again, thanks in advance,

Roger

 

 

Given the presence of insulated rail joiners at each end of the short bit of track then it seems to me there is only way one way the short can occur where it is.  That is if the lower rail of said bit of track is connected to the wrong side of the District 2 DCC bus so a short occurs every time the loco bridges the insulated rail joiners.

 

Short out the two rails on that little bit of track with a coin and see if it trips out.  If it doesn't then you have your answer.

 

Edited November 8, 2020 by DY444

[RobinofLoxley]

1 minute ago, DY444 said:

Given the presence of insulated rail joiners at each end of the short bit of track and then it seems to me there is only way one way the short can occur where it is.  That is if the lower rail of said bit of track is connected to the wrong side of the District 2 DCC bus so a short occurs every time the loco bridges the insulated rail joiners.

 

As I said about half a mile further up the thread

[DY444]

56 minutes ago, RobinofLoxley said:

As I said about half a mile further up the thread

As did I but nobody is listening 

 

And if it isn't that then it'll probably be that the District 2 DCC bus track connections are reversed relative to District 1 although then the short would only occur when the loco crossed the District 1 to District 2 boundary at the left end of the short bit of track and it is not clear from the OP whether this is the case or not.

 

In all probability putting a coin across the rails on the short bit of track will reveal all:

Coin causes no short = lower rail on short bit of track connected to the wrong side of the District 2 bus

Coin causes short = District 2 DCC bus track connections reversed relative to District 1

Edited November 8, 2020 by DY444

[StanierBlack5]

I've done what has been suggested and placed a coin across the rails of the short piece of track which caused a short - the light for district 2 lit up, so what is my next move to rectify my problem?

 

Thanks in advance,

Roger

[DY444]

2 hours ago, StanierBlack5 said:

I've done what has been suggested and placed a coin across the rails of the short piece of track which caused a short - the light for district 2 lit up, so what is my next move to rectify my problem?

 

Thanks in advance,

Roger

 

You need to confirm the precise point where the loco causes the short.  Is it where it crosses the boundary between district 1 and district 2 and only there? 

Edited November 8, 2020 by DY444

[long island jack]

if this was me, this is how i would do it

 

[newbryford]

3 hours ago, long island jack said:

if this was me, this is how i would do it

 

 

 

Ray has shown the insulators on both v-ends of the points - as suggested earlier.

The only thing I would do is move one of the two that form the crossover, so that they are opposite each other - for the district separation.