DCC Electrics problem

[JB59]

Was doing okay until I wired up this junction. DCC Buswires are radial. All points are insulfrog with insulator fishplates as marked in yellow. Dropper feeds are as shown, black to the back, red to the front. Points are motorised but powered using the DCC Ultimate turnout pack so work independant of the DCC system. I purposely chose insulfrog so I would not have to worry about over-complicated electrics (for me !) Whenever I now turn on the Elite, it comes up with an error message.

Have I done something wrong here ? One thing I have done which may be wrong, is to solder a wire between the main rails (two black rails joined and two red rails joined) as shown in this picture ?

Any comments most welcome thanks !

[96RAF]

You obviously have a short so start by disconnecting those two rails in the picture.

[RDS]

I cannot imagine that those soldered wires caused your problem because they appear to be in exactly the same position as required by the Hornby Point clips that are used on DCC. Of which I have 35 sets on my layout.

Make sure that all your dropper wires are connected to the correct rail, as that is the easiest way to unknowingly create a Short Circuit.

[Chrissaf]

You say they are Insulfrog. If so, then I just point out that there is no technical need for the insulated rail joiners (yellow). Insulated rail joiners at that location are only relevant when using PECO Electrofrog points.

If these are Hornby points (you haven't stated the brand) then if the droppers are not reversed as RDS suggested, then the point has a common factory short circuit fault. At the top of the 'General Discussion' forum is a sticky thread titled 'General Discussion FAQ Index' open this thread and read FAQ 4.

[JB59]

All the points are PECO ST-240/ST-241. I know there was no need to fit insulated joiners but as every track section has droppers I did it as an extra precaution.

[JB59]

Have checked all the droppers are correct, as indicated on the picture.

[Flashbang]

Somewhere you have a positive rail abutting a negative rail. Only by removing all the droppers and starting from the beginning can you determine which connection is causing the problem. So once all connections are disconnected, apply DCC power and ensure all is good. No shorts with any point position.

Assuming all is good then connect one pair of droppers at a time and retest to prove if a short occurs when any point or that dropper pair is incorrect. After connecting the first one and if OK continue on until hopefully the short is discovered and then resolve by correcting that connection.

[96RAF]

Have you by chance introduced a reverse loop.

[Chrissaf]

Just to add to Rob's reverse loop suggestion. Your photos do not show your layout in its entirety for us to review for reverse loops. So as a textual description of what consists a reverse loop, I use this definition.

"Any path that can be taken through the layout regardless of complexity that allows a loco to arrive back at its starting position but facing the opposite direction."

This includes Turntables.

Reverse loops generate an instant short circuit. If there is a path through your layout that meets the above definition, then download my 'Reverse Loop Tutorial' pdf from the sticky post at the top of the DCC forum that describes how to resolve 'DCC reverse loop short circuit issues'.

[37lover]

As a variation on Flashbang's suggestion, and something you may have thought of yourself, you could disconnect only a couple of droppers, test and then repeat as required until the fault is rectified. If you are lucky you may only need to remove a few rather than all.

[JB59]

Thanks for the suggestions. I disconnected all the droppers and confirmed continuity to both ends of the buswire. As soon as I connect one dropper Elite gives an error warning, and this is on an area that previously was okay. Droppers are connected to a 12 way terminal block which is then connected to the buswire using splice connectors as in the picture. This is what is wired so far.

[JB59]

Trying to post pics of the layout so far but does not seem to want to post them !?

[Chrissaf]

All posted images are held back for moderator approval thus there is a delay and they do not appear instantly. I have just approved your queued images and removed your duplicated posts. Your approved images appear at the end of the previous page.

Quote "I disconnected all the droppers and confirmed continuity to both ends of the buswire. As soon as I connect one dropper Elite gives an error warning"

I suggest that you use a Multimeter [measuring Ohms resistance] to identify where the short is originating from. Start with measuring across the two rails before any droppers are attached. If the rails show a short then there is a fault in the track (or a reverse loop as previously suggested). If the rails are clear of a short, then the short is in your BUS wiring. Using a meter is the most efficient way of finding it. Don't have one.... they can be purchased from eBay for less than £8 delivered.

[Flashbang]

I cannot see any gaps in the points two closure rails?

You cannot bond stock rail to closure rail on each side of a Electrofrog point without having these two rail gaps! No gap equals a full short circuit!

Then when you have the two gaps you will also need some means of applying the correct polarity feed to the rails after the gaps into the frog and out to the IRJs on the ends of the Vee rails. This is usually done by a point motor operated change over switch feeding the frog. But can be manually switched or by a surface mounted small micro switch fitted adjacent to one side of the point and whose operating lever is depressed in one point position by the points moving stretcher (Tie) bar.

[Chrissaf]

FB,

The OP is not using Electrofrogs. He stated PECO ST 240 / 241 Insulfrog points. Therefore given that PECO ST points are clones of Hornby's design. It is assumed that the frog rails are isolated from each other as Hornby points would be.

Yes I know that the OP has included IRJs that Electrofrog points use. This has been pointed out to him in a previous reply. In theory, the wire dropper links between the moving and fixed rails are just emulating what Hornby R8232 DCC point clips would perform on Hornby points.

[JB59]

Have you by chance introduced a reverse loop.

 

 

No reverse loop. Just two facing points connecting two main tracks. The first set worked okay.

[JB59]

[Chrissaf]

JB,

Please note that the photos above are duplicates of the images you posted on the previous thread page.

[Going Spare]

If all the other points have been wired in exactly the same fashion without any problem, this line of thought is obviously a non-starter, but if this is the first point tackled, I wonder whether the Peco points do differ in their construction or in-built wiring from Hornby's so that wiring them for DCC in this way does create a short-circuit?

[JB59]

Many thanks Chris, Multimeter ordered have never used one. As an electrical novice, might need some guidance on what settings to use on it before testing!

[Chrissaf]

In my very first reply to your post on 'Page 1' of this thread I made mention of FAQ4. This FAQ documents some guidance with regard how to use a Multimeter to measure resistance to identify a short circuit.

[Brew Man]

If all the other points have been wired in exactly the same fashion without any problem, this line of thought is obviously a non-starter, but if this is the first point tackled, I wonder whether the Peco points do differ in their construction or in-built wiring from Hornby's so that wiring them for DCC in this way does create a short-circuit?

 

 

I've never wired them in that way but I have used Hornby point clips on Peco points which is electrically the same with no problem.

[Brew Man]

@JB59

Are you absolutely sure you don't have any Hornby points in the mix there?

[JB59]

@JB59

Are you absolutely sure you don't have any Hornby points in the mix there?

 

 

All PECO

[JB59]

Layout diagram. All went well with boards 1-5 (circled in red) it was when I connected boards 6 and 7 that the error appeared.