Wiring help with fiddle yard throat

[Chrissaf]

Is the black track section A at that location longer than the Pendolino motor car?

Is the red track section marked B longer than the whole length of the Pendolino train including carriages?

Does the Pendolino trip the Elite at ANY other location on the layout?

Does the Pendolino still trip at the arrow location if turned around 180° and going round the loop in the other direction? (as opposed to just going in reverse).

Do the Pendolino carriages have any wheel pickups of their own, perhaps for internal lighting.

Do the Pendolino carriages have couplings that also provide electrical pass through from one carriage to another?

Do you have the same issue if you only run the Pendolino motor car on its own without any attached carriages?

[paul.b]

Hi chriss

Answer to q1 is yes 

q2 yes

q3 no

q4 yet to try that

q5 no

q6 no

q7 yet to try that

[Chrissaf]

Now you have used the term "TRIP" in your question. TRIP infers a 'short circuit', yet you go on to say that the Elite resets and the Pendolino starts off again. If the Elite is tripping due to a 'short' then 'ERROR' will show in the display and any reset will need to be MANUALLY implemented by pressing the Elite 'Escape' key.

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Do you get the 'ERROR' display in the Elite LCD screen?

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If the Elite just auto resets and the Pendolino just starts up again on its own without needing to be manually reset. Then that will be due to an intermittent pick up power break at that particular track location. In which case start looking at the Pendolino pickups and how flat and level the track is at that particular spot. Perhaps an extra track pin or two in the that area, plus some extra enthusiastic rail cleaning at that location too.

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If 'ERROR' is displayed, then the issue is an intermittent 'short' in which case:

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If you try Q4, then that could indicate that the short is caused by the bogie favouring one particular direction of bogie side pressure, particularly if it also happens to be on a curve section of track. It could also be an indicator as to whether the issue is directly track related or specific to the Pendolino motor car.

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If you try Q7 suggestion, then that would completely eliminate the attached rolling stock from the equation if the fault still persists with the motor car on its own.

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In general, as the other locos you have are not affected (apparently), then that would tend to indicate that the track and the RLM design is performing to specification.

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[paul.b]

Hi Chriss

just tried the pendolino going the other way and now i get a full short at a completly differint place and error on the elite so i tried it with just the power car and same again error  on elite at same new spot 

/media/tinymce_upload/bda7c7cf8421837e140b197aad578f2c.jpg

[paul.b]

At the new spot it crosses the point enters the first RLM section and shorts elite i reset and it carries on over the spot with the original problem and when gets back round the layout to the points it croses the point and shorts again cant get a full loop of the layout 

[Chrissaf]

What switch position are the R8238s in, are they in the Elite position or the Select position. Just because you have an Elite, does not necessarily mean that you have to have the R8238 in the Elite switch position. It is rather misleading of Hornby to use these switch label terms on the R8238. The switch position determines the RLM trigger current. The Select position is about 0.8 amps and the Elite position is nearer 3 amps. I would recommend using the Select switch position for more sensitive trigger current detection. If the R8238 is in the Elite position, then it may be that the Elite is going into 'short circuit' detection mode faster than the R8238 is switching. This could also potentially account for why this issue is intermittent, sometimes the Elite triggers first, sometimes it doesn't.

[paul.b]

Hi Chriss

I`m completley at a loss here i have set the RLM to the select setting and still the same now its happening to all locos as i enter the first RLM just the loco no rolling stock. i have an electrofrog point at the point of entry to the RLM as soon as it crosses the frog and enters the section it shorts  i have IRJ on the frog and on the other rail into the RLM sometimes any loco will go over no issues then it could do 1 or 2 loops and then short, i can hear the RLM trying to switch but the elite beats it to it  

[Chrissaf]

Well in the short term go back to the Elite position.

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In the longer term, review how you have wired up the electrofrog.

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1. Are you using the elctrofrog point 'as is' straight out of the box?
2. Are you using switched polarity on the frog and if so how?
3. Are BOTH frog rails on the output of the electrofrog fitted with IRJs?

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Try swooping the two R8238 RLM over, does the issue move with the R8238 or stay the same?

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If the issue moves with the R8238 then that could indicate the R8238 is out of spec in some way or faulty.

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Reading your post again it infers that the IRJ's are staggered some distance apart where a RLM protected section joins a normal track section. The two IRJs should (ideally) be co-located together. RLM theory should allow IRJs to be staggered, but 'best engineering' practice says co-locate them.

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/media/tinymce_upload/7439b41ad8b8f16c692e76b4a78dfe13.jpg

Can you clarify for me which points have the electrofrogs, because I was under the impression that the throat points were Insulfrogs. Are the electrofrogs the points on the far left hand side of the drawing that form the input and output of the triangular WYE.

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Can you produce a more detailed sketch showing exactly where the IRJs are fitted?

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Is just that I am starting to get confused. Because you indicated in the earlier reply that the short was happening on the black section of track near the large wide arrow you added to the drawing (nowhere near a point). Now you seem to be saying that the short is happening when traversing an electrofrog point.

[paul.b]

Hi Chriss 

I have moded the point bonding the rails with the switch blades and removed the small wires which join the blades to the frog. i use the ADS to control frog polarity i know frog is ok if i set the points to stay on the main layout no short 

[paul.b]

Hi chriss

it happening at both places i will try and do a drawing showing where everything is all irj are located together 

[Chrissaf]

Mark also as accurately as you can the position where the loco is shorting. And what track sections connect to what supply i.e Elite or RLM1 or RLM2

[paul.b]

Hi Chriss i have sent you an email

[Chrissaf]

Forum update (for any member who has been following this thread):

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I have been working with Paul behind the scenes via email last night and further this morning to help resolve his 'short circuit' issue. After much diagnostic testing the issue focused on RLM1 in the diagram above not switching when the short was detected.

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The RLM layout plan was simplified to remove the RLM2 protected section so that the whole track section of this part of the layout was via a single RLM. The RED track section on the right annotated as section B in the drawing above is now connected to the main track DCC Bus. This meant that the suspected faulty RLM1 R8238 could be replaced by the now free RLM2 R8238 for ongoing diagnostic testing.

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The primary identified issue was the R8238 switch position. This was originally in the Elite switch position where the short circuit trigger current is about 3 amps. Given that Paul has got 9 ADS decoders and a number of other locos potentially drawing background current. The R8238 RLM Elite switch position (3 amp) trigger current was too high. Because of the ambient background current already being drawn from the Elite 4 amp supply, the Elite was reaching its own 'short circuit' detection current setting before the R8238 could be saturated with enough current to trigger first. This was resolved by putting the R8238 into the Select trigger current position which has a target switch current of nominally 800mA.

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There are one or two other minor issues left to resolve, which would probably need the R8239 Power Booster solution documented previously in this thread to reduce the ambient power current load on the Elite 4 amp supply, so that there is a higher spare current overhead to accommodate the R8238 RLM. Another possible enhancement would be to replace the R8238 with a RLM product that has greater scope for configuring trip currents. The configurable trip currents of the R8238 are somewhat extremes at 0.8A & 3A respectively.

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At the time of writing this update Paul has a working layout with perhaps a couple of bits of tweaking to do as outlined above.

[Chrissaf]

Hi just seen this on youtube about ads8sx /2sx giving a short at first power on and dcc concepts sent  a fix for it ....exactly what i am getting on power up with all decoders connected 

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This is a follow up post from one that was originally posted on Page 4 of this thread.

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As well as Paul, I too have been in email dialogue with DCC Concepts regarding the fix device shown in this video. This is a summary of the mails I have received from them:

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We had a look at the video and it does make some sense when we saw the DCC system.

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The bottom line is that the ADS is not at fault - but the Circuit Breaker feeding it is too reactively sensitive. Perfect for an IT application but not generous enough to allow, say, a 1/10th second delay before reacting.

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Some power supplies are the same. We do see a trend of newer DCC products making this mistake.

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The 'Inductive Buffer' creates that delay long enough to allow the CB to react less impulsively!

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With specific regard to the product in the video.

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1. It does not have an official part number.
2. It is not orderable.
3. It is only provided as and when there are issues with start up current with a particular set of components (see below)

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The vast majority of ADS units are installed and running perfectly well without any need for our delay units.

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We have not supplied them to the user in the video, he has got them via DCC Train Automation who supplied his Digikeis unit. We did not know that they were being provided by DCC Train Automation for use with ADS units.

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They were originally designed for use with our small DCC accessory driver when connected to the Cobalt SS point motors, which was prone to the same rapid shutdown as the video user has experienced with his Digikeis system (future production of the accessory driver will have the short circuit protection de-sensitised slightly).

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As such, we supplied a few to DCCTA and a couple of other dealers selling our products.

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The best recommendation is to provide a switch in the DCC feed to each ADS unit, so they can powered up individually - much like starting an airplane with four engines - they are started one at a time. Or in the case of some DCC equipment, another solution may be to alter the trip settings.

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I basically read this last mail from DCC Concepts being that the chance of getting some of these products from them is close to zero.

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Note that they use the term 'Inductive Buffer'. This infers that the key components in the product are Inductors and not resistors as the video presenter surmised.

[Fishmanoz]

Makes sense when you think about it. An inductor is liable to compromise the steady state supply volts to the ADS less than a series resistor. And will look like an open circuit to the leading edge of the supply volts at switch-on. 

[96RAF]

Going back to the RLM issue and the possible need to introduce a Signal and Power Booster, remember the Hornby booster also functions as an RLM, which may be of use In the design.

Rob

[paul.b]

Hi Guys 

Just an update on this thread, I took the plunge and bought a hornby booster from ebay brand new and never used a bargain at £50. I fitted the booster as per chriss instructions an powered my 5 ADS8SX from the booster and straight away I got an overload and the booster shut down.

 

So I ended up with 3 of my 5 ADS8X and 2 of my 4 ADS2SX on the booster ( any more than that and the boosters overload light came on) and the rest of the ADS8SX/2SX conected to the main bus.

 

I now have no power up issues and the RLM works perfectly with all loco`s in both directions including my pendolino which would only run one way round the loop and at reduced speed, it now runs both directions and at full speed no issues.

I now have a fully working layout with a reverse loop and all issues resolved, I would like to thank everyone who inputted to the problems i was having and a special thanks to Chrissaf for all the email help..

 

paul

[Chrissaf]

....and a special thanks to Chrissaf for all the email help....

 

😀 Thanks

[paul.b]

Hi All

Sorry I`ve been away for a few months but took some time away from the layout when my wife passed in march but trying to get back to as normal as possible.

I am thinking of adding a second level to the layout and have a question. The fiddle yard is marked in the red box and /media/tinymce_upload/96cde0985956ba13141b1ec512b3225c.jpg connected to a reverse loop module (RLM) and i want to add a helix to the end of the layout to take me down to the lower level.

Will this cause issues with the RLM with trains entering the helix and exiting at the same time? the fiddle yard is marked with yellow dots to represent isolated rail joiners and the helix will be connected to the main bus as will the lower level

Regards Paul.........

[Chrissaf]

Sorry to hear about your loss.

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The same RLM rules that we have already discussed will apply. Trains should not enter and leave a RLM section at the same time and two RLM sections should not connect directly together.

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If the helix is connected to the main layout on the lower level. Then treat that as just an extension of the main layout. I can't see the detail of the track topology from the 3D image you have posted, but as long as the rules above are adhered to, there shouldn't be an issue.

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On the concept of a Helix in general, I'll leave others to comment. But this I will say. It is the same with any form of gradient and slope. Drag on curves compared to drag on straights is increased and a Helix compounds this even further. The original (now decommissioned) Everard Junction layout had a Helix at each end of his layout. He found he could only run heavy multi-wheel drive diesels on it and the Helix caused a lot of running issues that he only really voiced when he explained his rationale for building his new layout. His new layout removed the Helix ends. They need a lot of space (diameter) if the gradient in them is going to work. Remember that each complete circle of a Helix has to rise enough to clear the rolling stock.

[paul.b]

Hi Chris

Thankyou for the info.... I have uploaded a better pic of the layout the lower level and upper level will in reality be a huge loop, trains will travel round the top level through the RLM section down the helix round the bottom level back up the helix back through the RLM and round the top level.

/media/tinymce_upload/3fcdcffae1b0b602f1d6d977d247fca2.jpg

The arrows show direction of travel,I was hoping to be able to run a few trains on this huge main loop and was unsure if a train was coming up the helix and entered the RLM just as a train left the RLM to go down the helix would this cause RLM issues.

As to the helix its self I have the space and am in the design stage it works out at a 1.9% grade over the total run, I knocked up a trial helix at this grade and my pendolino ,hst 125 (with cd motor conversion ) and flying scotsman can all make it up... the scotsman with four coaches.

Regards paul....

[paul.b]

Chris

I forgot to mention in my last post there is only one RLM section as we disscused when i first started this thread we did away with the second RLM 

Paul....

[westernwill]

Hi Paul

 

I have a similar setup to your proposed one albeit without the fiddle yard where you have it.

 

I have a large loop on top and bottom joined by the helix. Because I can crossover the same loop I ended up putting 2 RLM's in with lengths just a little longer than my longest train and have had no problems so far. I can comfortably run 3 trains on the circuit and, if I really concentrate 4, it is nice to have a really long loop. I set up led strip lights on the lower section to be able to see what was happening.

 

I run mostly steam engines with 3 or 4 coaches attached and have had no problem with the gradient.

 

Hope you enjoy it all when it is built.

[paul.b]

Hi

Thanks for the help and encouragement guys I think this crude drawing will clear up how the RLM is connected to the layout currently albeit withot the helix at the present time the helix is just a loop and that loop going back to the main layout is connected to the main bus.

The drawing is how it will be connected when the helix is built 

/media/tinymce_upload/dc63aeb148d9b9824cedccfa9069fc3c.jpg

I have a spare RLM if needed for this design .....

Paul.....

[Chrissaf]

Yes that is a better image to work from.

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After some further consideration based on this new drawing........I can't see any easy and obvious solution to your issue. The fiddle yard throat section that lies between the four yellow dots that denote IRJs are protected by a RLM. Thus in this proposed new topology there are four potential access points to that section. Potentially, there is a possibility that any two of those four access points could have trains traversing the insulated joints at the same time which would be in breach of RLM (best engineering) design guidelines.

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