Digitrax DCS100

[trainforfun]

Hi
I have this model since about 15 years .
Yesterday everything was great , shut it off to go to lunch when I came back there was a short on the layout .
The layout is 16' x16' with three
 district one controled by DCS 100 , another portion  by a DB150 ( slaved of the DCS100 ) and another portion by I forgot the name .
Everything is well for the last 5 years I would say . There is like well over 100 locos , half of them are parked on dead sidings  ( controlled by a toggle switch ) and the rest are on trains that have 3 or 4 or 5 locomotives in consist .
A few of them , maybe 10  have sound , only one is BLI with sound , this one is consuming more amps than the ATLAS  one .
The rating of the DCS100 is 5 amps , this morning I fired it and everything was fine , as per my power pack there was only 1.5 amp , suddenly after 10 minutes a short again , no trains were running .....
I wonder if after a certain time the breaker inside become weak and more fragile to load . Probably with the temperature rising inside the DCS100 .
What do you think ??
I went thru all the DIGITRAX literature and no word about it ...

[nickelplate759]

I think it's more likely that an intermittent short has developed in your layout or wiring than in the Digitrax system (although anything is possible).
Time for serious troublshooting.

If it's in the Digitrax system, it should happen when connected to much less than the entire layout.  Try connecting it to a smallish isolated piece of track, but FIRST check that that track has no shorts in it.  Then use the Digitrax and see if the short still happens - bet it doesn't!

If the short doesn't happen on a test track, it's likely that it's something on our layout, or part of the layout itself. 
Step one would be to see if the problem is specific one one of your three power districts - isolate each district and test each district separately.  There's a good chance that the problem is unique to one of the districts.

Now it get's tedious - I'd remove every piece of rolling stock from the "bad" district, see if the problem persists.  If it's gone - it's something in the rolling stock.
after that, you may have to go hunting with continuity testing, etc...

[peteski]

Yes, like George mentioned, isolate the problem to a single district, then work your way through it to find the problem.

You didn't specify it, but I'm assuming that since you have 3 districts only one is shorted (or being overloaded).  If all 3 districts are "shorted" or overloaded, it is one strange problem.

I also don't think that the breaker got weaker with age.  Those are likely solid-state breakers which should always function the same as the day you bought them.

[trainforfun]

Yes it's an intermittent short that have developped like yesterday morning !!!!

The third sector is run by a TAM Booster of 5 amps , no problem on this one , it's a big yard where many trains are stored with many locomotives on each  .

The second one is run by the DB150 , no problem on this one also , it's also a big yard with many long trains with many locomotives on each  .

The faulty one is the one run by the DSC100 ....
It runs a longer mainline , I can isolate the main line in many place , so I shaould be able to pinpoint where it comes from , hopefully .

I tried to connect only a short piece of track , really that piece of track is my programming track with a DPDT toggle switch , one side is for programming , the other is rails A and B , I tried to put many locos on it and it never trigged the breaker ....

Thanks Pete for your answer about the breaker getting weak after a while on the DSC100 .

I ordered a 12 vdc cooling fan on AMAZON ( $ 12 ) that I tought would help to cool the DCS 100 , I will receive it tomorrow but it seems that I have a short on the mainline somewhere , so I will have a fan for nothing !

I am suspecting a loose "glad hand" from an ATLAS car that could have fell in a turnout frog or something like that ...
But why is it intermittent ......

[John]

The faulty one is the one run by the DSC100 ....
It runs a longer mainline , I can isolate the main line in many place , so I shaould be able to pinpoint where it comes from , hopefully .

This is like playing a game of Clue -- the buttler in the drawing room with a DCC booster

Replace the DCS100 with one of the other boosters .. turn it on and see if the problem goes away .. thats a simple swap .. easy test

DCS100s are fairly old .. and there are a couple of big capacitors in them ..

[John]

I am suspecting a loose "glad hand" from an ATLAS car that could have fell in a turnout frog or something like that ...
But why is it intermittent ......

shopvac .. it happens

[mmyers]

You might also have a look at your DCS100 power supply. It may be failing to supply the current required when under load. Eric -Seusscaboose can tell you all about chasing that one down.

[Bill H]

I was recently operating on a very large, very well known and very stable layout. Suddenly one session, shorts mysteriously appeared. I am talking about a layout of 30+ years at operational status.

What happened? The owner replaced an old HVAC system with a new brand new high efficiency heat pump and refreshed duct work. That new system apparently pulled a lot more moisture out of the basement and cooled the basement much better with 20+ operators in the room. Wood shrank. Rail gaps that had been gaped just fine, suddenly shorted, and after 30+ years, the owner had to go back and widen all the gaps. And with that, all the mystery shorts disappeared.

Just a thought...

Kind regards,
Bill

[trainforfun]

I was recently operating on a very large, very well known and very stable layout. Suddenly one session, shorts mysteriously appeared. I am talking about a layout of 30+ years at operational status.

What happened? The owner replaced an old HVAC system with a new brand new high efficiency heat pump and refreshed duct work. That new system apparently pulled a lot more moisture out of the basement and cooled the basement much better with 20+ operators in the room. Wood shrank. Rail gaps that had been gaped just fine, suddenly shorted, and after 30+ years, the owner had to go back and widen all the gaps. And with that, all the mystery shorts disappeared.

Just a thought...

Kind regards,
Bill

Wow must have been quite a search to find where was the problem  ....
My room is at the same temperature all year long , we had a lot of rain this summer , could be more humid but not that much , I don't feel it anyway
I have disconnected all reverser unit , one by one
I removed from the the track that are not feed thru a toggle switch all locomotives or car that pick up current , I had one a year ago that the decoder blew and it gave me a short circuit

The short circuit is still there and a strong one , when I hook up the wires to the DCS100 there is a spark and then the breaker does it job .

So I am inspecting the tracks , and I will have to check the bus if everything looks OK.
My big layout was built in 3'x 6' modules and there is plugs with multiple connectors , it's easy to unplug but over the years the lousy guy here have bypass the plugs at some places for new installation....

[John]

The short circuit is still there and a strong one , when I hook up the wires to the DCS100 there is a spark and then the breaker does it job .

So I am inspecting the tracks , and I will have to check the bus if everything looks OK.
My big layout was built in 3'x 6' modules and there is plugs with multiple connectors , it's easy to unplug but over the years the lousy guy here have bypass the plugs at some places for new installation....

It's good that you have modular sections .. classic electronic troubleshooting consists of dividing the problem into 1/2 .. disconnect 1/2 of the layout. If the problem is gone, its on that half - then subdivide that 1/2  into another half .. continue until you isolate .. good luck

do you remember if you made any adjustments just before the problem appeared?

[trainforfun]

It's good that you have modular sections .. classic electronic troubleshooting consists of dividing the problem into 1/2 .. disconnect 1/2 of the layout. If the problem is gone, its on that half - then subdivide that 1/2  into another half .. continue until you isolate .. good luck

do you remember if you made any adjustments just before the problem appeared?

That's a good point , when I work on the layout I usually leave a train running on a long run that takes about 10 minutes to do a lap .
First because it's like railfanning and second if I do something wrong I will know right away .
I was working on new lighting in a building , did not finished left the building unplugged , shut the main switch when I left , came back 1 hour after , it worked 10 seconds and poof !
Trying to think backward , what I did before etc etc
I am doing some clean up in the wiring , I will find it !!!

[John]

That area may be a good start .. if you are using the DCC bus to power lights, then its possible there is a cross in there ...  remember - Model Railroading is Fun

[trainforfun]

...  remember - Model Railroading is Fun

These days I am trying to convince myself of that !!!!!

[trainforfun]

I was recently operating on a very large, very well known and very stable layout. Suddenly one session, shorts mysteriously appeared. I am talking about a layout of 30+ years at operational status.

What happened? The owner replaced an old HVAC system with a new brand new high efficiency heat pump and refreshed duct work. That new system apparently pulled a lot more moisture out of the basement and cooled the basement much better with 20+ operators in the room. Wood shrank. Rail gaps that had been gaped just fine, suddenly shorted, and after 30+ years, the owner had to go back and widen all the gaps. And with that, all the mystery shorts disappeared.

Just a thought...

Kind regards,
Bill

I was able to divide the main line part in 2 , I added some toggle switch , cleaned the wiring in some parts ,this wiring is like 25 years old and the insulation is dry and bristle .
The humidity thing is really probable , but a little piece of metal is still in the probability.
The DCS 100 is not the culprit,  when I try to reconnect the total main to the system the spark is solid , not just a little chicken spark !
Still searching 

[peteski]

The DCS 100 is not the culprit . . .

Not surprising.
If you keep dividing the search area like John recommended, it will greatly help in finding the problem.