Loco moves at zero throttle ?

[Anton Stedman]

However I do have the R8201 DCC Link wires and I tried it with them but the same overload message came up almost straight away after I started the train up.

[Chrissaf]

@Anton,

One thing you can try.

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Put the Select into Address Zero mode. Now turn the speed knob all the way up and then all the way down to the stop position. Then choose a valid loco DCC address of one of your locos to come out of the Select Address Zero mode.

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Sometimes, if you have previously been using Address Zero mode and not fully reduced the speed knob to zero before calling up a valid DCC loco to control, the controller sort of gets confused and remembers the zero address throttle setting that was last used and then uses that as the stopped position with the subsequent DCC locos.

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As to your statement:

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"I also used to run analogue locomotives on the layout using the Analogue locomotive control but when I told Hornby this they said they do not recommend it. I have now stopped using this mode (not quite sure why Hornby bothered creating it if they do not recommend it)."

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This is historical legacy. You have to go back to when DCC was in its very early development. The majority of model railways worldwide would have been Analogue. Then comes along the first manufacturer (not necessarily Hornby) to release a DCC system. Now that manufacturer wants to make their DCC product palatable to as many existing Analogue users as possible. Thus the inclusion of the 'Address Zero' feature. They know that it is not an ideal technical solution to Analogue control, but it is their only option to maximise market penetration for this new emerging DCC technology.

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As new manufacturers enter the DCC market, they too adopt the 'Address Zero' feature for the same market led reasons.

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Time moves on and DCC takes a foot hold in the market and becomes less of a niche technology. Manufacturers are aware of the risk of damage that using Address Zero can do to an Analogue loco motor and start to drop the Address Zero feature from their products. In the current market, this feature is being dropped from products and it will only be a matter of time before it dies out all together.

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Hornby are correct to advise you not to use it, you do risk permanently damaging your analogue loco motors. Want to know more on why this is so, then read this web article by Mark Gurries. Mark is a member of the NMRA, the body that wrote the DCC standards. So the information in this article is coming straight from the horses mouth.

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https://sites.google.com/site/markgurries/home/technical-discussions/dc-loco-on-dcc

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PS - If you are sure that you are using a R8241 (the power track on the end of your posted link) that is fine, but do make sure that you are not also using any OTHER power clips / power tracks on your layout that are not the DC friendly versions.

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UPDATED EDIT: In light of your updated reply made at 15:04 above, which I have just seen:

 

You have stated that you are using the Hornby R8201 Link Wire product, these use Analogue power clips and are not DCC friendly. The R8201 is not intended for DCC use. There was a time when the Hornby Shop product page mentioned use for DCC in the product description. This was an error that has now been rectified and the reference to DCC removed.These Analogue clip products contain 0.1uF suppression capacitors that are wired across the track. The capacitors can cause OL to be displayed on the Select and the capacitors must be removed - see image below.

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To be 'belt n braces' I would check ALL your power track / clips that are used on your layout regardless of where they are implemented for a capacitor and remove ALL capacitors that you find. As well as the OL, these capacitors do affect the ability to control a DCC loco and can cause some intermittent erratic operational behaviours to be observed (which is why previous posters mentioned them). The fact that you have got at least one R8201 on your layout is almost certainly the cause of your issue.

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On a DCC Layout there is no need to use a R8201 Link Wire. The electrical functionality that this provides is performed by fitting R8232 DCC Point clips to all your points instead. The R8201 was always designed for use on a Hornby DC Analogue controlled layout. The only reason for using a R8201 on a DCC layout is if the points that create a cross-over between inner and outer loops have Insulated Rail Joiners (IRJs) fitted. In which case, use the R8201 but perform the capacitor removal procedure shown below on BOTH R8201 track clips.

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The image below gives guidance on what to check for:

/media/tinymce_upload/b62f9143a838241df18d4d246d7a8918.jpg

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TIP: I write long posts. If you intend to write a reply, it would be appreciated if you didn't use the 'White Arrow in Blue Box' button. This is not a 'Reply to this post button. It is best to write any reply you want to make in the 'Reply Text Box' at the very bottom of the page and click the Green 'Reply' button.

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Particularly as my reply includes an image. If you use the blue button, any reply you write may be held back for image approval. Even though it is already a previously published image.

[Anton Stedman]

Thanks for the help.

I didnt realise about the R8201 not being DCC friendly. I do not use them anyway. I have been meaning to sell them, so they have never been on the layout recently. I am sure that the power track I use is DCC friendly because it came with my Somerset Belle DCC Train Set.

I will try the first part of your answer now.

[Chrissaf]

Check the power track as well anyway. It has not been unknown for the Belle set to ship with an Analogue power track by mistake.

[Anton Stedman]

I have just tried this part of your post:

Put the Select into Address Zero mode. Now turn the speed knob all the way up and then all the way down to the stop position. Then choose a valid loco DCC address of one of your locos to come out of the Select Address Zero mode.

The analogue locomotive went up to full speed fine but when the control throttle was brought down to zero it kept gradually moving. The DCC fitted loco however did stop completly when the throttle was at zero. This is what I meant when I said it was an intermittent problem, the DCC locos sometimes keep going but the analogue loco always keeps going (very slowly) or sounds as if it about to go (I realise that analogue locos hum when put on a DCC track but this humming is different and if you push the loco along it slowly move forward). I think the controller is giving the locos a tiny amount of power but not enough for the DCC locos to respond to. 

I also tried changing the speed steps to prove this. On speed steps 14 and 28 all locos stopped completely and the analogue one no longer sounded like it was about to move off. This is why I think it has something to do with the control throttle. Maybe the inside of the controller is not completely cutting the power to each locomotive even though the white arrow on the control knob is pointing at zero speed.

[walkingthedog]

I haven’t read all the posts but are you running DC analogue locos on DCC. Don’t, you will burn out the motor. 

[Anton Stedman]

/media/tinymce_upload/1a8b107b4e87f7a3ca598a6f5addab63.jpg

This is what it looked like.

[Anton Stedman]

I haven’t read all the posts but are you running DC analogue locos on DCC.

No, after phoning Hornby Customer Service I have stopped using this mode. They told me what you have just said: it will burn out the motor.

[Chrissaf]

DCC using a bi-polar square waveform which is a form of AC (Alternating Current). DCC Address Zero uses something called 'Zero Bit Stretching'. In Address Zero mode, the controller does not cut the power to the track when the control knob is at zero speed with an Analogue loco. Instead it tries to keep the voltage bias zero such that the overall track voltage is neither positive or negative. If this bias is not completely neutral (zero) then a sensitive Analogue loco motor can still react to it and move slightly.

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Zero Bit Stretching is explained here:

https://dccwiki.com/Zero_Stretching

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But since you have stated that you are no longer using the Address Zero feature, then this is a bit of a 'red herring' with regard your DCC loco creeping. You have already indicated that after performing my tip in my earlier reply, your DCC loco now no longer creeps.

[Anton Stedman]

Check the power track as well anyway. It has not been unknown for the Belle set to ship with an Analogue power track by mistake.

I have sent through a picture showing the DCC power track without a capacitor but the it doesn't seem to be going through.

[Chrissaf]

Images are held back for approval by the forum Administrator. The administrator only works UK Office Hours. Your image might appear before 5pm, but more likely tomorrow now. This assumes that you used the correct image upload procedure as documented here:

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https://www.hornby.com/uk-en/forum/how-do-i-include-an-image-photo-in-my-post/?p=1

[Anton Stedman]

Any ideas what to do next?

Should I send it in for repair at Hornby?

[walkingthedog]

What is the problem at present?

[Anton Stedman]

I am having the same problem as Paul60 but I am only 13 and cannot afford the Elite at the moment. However this fault is intermittent, sometimes the trains will stop when the throttle is set at zero and other times the trains keep moving at a very gradual pace (even when the throttle is at zero). The other problem is that the controller keeps displaying oL (overload) so I presume that means there is a short somwhere.

My first post back on page 3 of this topic gives more detail of the problem.

[Anton Stedman]

So basically the locos sometime move at zero throttle and the oL message keeps displaying even when there are no locos on the track. I am not quite sure but I think the 2 problems might have something to do with each other.

[Chrissaf]

Can I just say that your standard of writing skills and your understanding of DCC at aged 13, puts some of the others on here to shame.

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Problem with intermittent faults, is that sending it off to Hornby is that there is a very high probability that it will be returned as 'no fault found'.

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You mentioned 'test track'. I suggest that you create the biggest piece of test track you can with the track parts you have available to you (excluding points) that does not use your normal layout. Then run a loco back and forth on it for as long as it takes to be reasonably sure. Not so interested in the not coming to a complete standstill issue, it is the OL fault that will give a clearer indication of fault location.

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The idea being, is if you can replicate the OL display on the test track, then that would tend to infer that the fault is with the Select. If the OL display can only be reproduced when connected to your normal layout, then that would tend to indicate that there is an intermittent short circuit fault of some type on the normal layout track.

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Realistically, the straight and curved track pieces themselves are unlikely to have any scope for a short circuit fault. Any track fault that causes a short is more likely to be with a point or a scissor cross-over piece. Hornby points have been documented on the forum to have the occasional short fault, but these don't tend to be intermittent short faults (but anything is possible).

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Could you just confirm whether ALL your points have R8232 DCC point clips fitted or not. If you did have a faulty point, then if it is fitted with point clips, the short circuit would more likely be present on the layout permanently all the time.

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[96RAF]

I have seen this before and it is because the Select has had loco zero selected and a throttle amount set, possibly inadvertantly.

 

Even if you do not have a loco zero, select 0 and press the select button to invoke one, then open and close the throttle ensuring it hits zero at the end. This should clear your problem.

 

The other way to clear it is to reset the Select and ensure loco zero support is disabled when the option is presented (-0).

 

Select v1.6 will help here as loco zero will be disabled by default As it is on some other controllers.

 

Rob

[Anton Stedman]

Could you just confirm whether ALL your points have R8232 DCC point clips fitted or not. If you did have a faulty point, then if it is fitted with point clips, the short circuit would more likely be present on the layout permanently all the time.

 

There are about 20 points on the layout. Most of them have the R8232 DCC point clips fitted to them. Some of the points are new Bachmann ones which don't seem to need these clips as power is getting through to the whole of the point without them.

[Anton Stedman]

Even if you do not have a loco zero, select 0 and press the select button to invoke one, then open and close the throttle ensuring it hits zero at the end. This should clear your problem.

The other way to clear it is to reset the Select and ensure loco zero support is disabled when the option is presented (-0).

Thanks for the help. 😆

I tried opening and closing the throttle fully with it set a loco 0 but unfortunately this has made no difference.

I have also already reset the Select a few times and made sure the analogue control mode is switched off.

I was wondering whether this problem had something to do with CV2 but since you can only read and write this CV with an Elite controller this is not possible for me unless I asked a model shop or somewhere similar to do it for me. I don't totally understand everything about CV's, so sorry if this doesn't make sense.

 

 

[Anton Stedman]

As for the test track that Chrissaf said about.

Does the track included in it need to be track that hasn't been used on the layout. I do not have any spare curves so therefore cannot make a complete circle unless I use track from my layout.

[Chrissaf]

OK, if your layout is not pinned down and can be taken apart, then by all means use those track parts, just make a very simple circle or oval out of basic straights and curves and exclude any points and scissor cross-overs. In other words, exclude any track parts that could feasibly be a source of a short circuit.

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Although totally familiar with Hornby and Peco points. I have no knowledge of Bachmann points. For example, with Peco electrofrog points you have to use Insulated Rail Joiners else you get a short. But whether there is something similar with Bachmann points I couldn't say. Another reason for making the 'test layout' a layout without points in it.

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20 points is quite a lot of points. So if you cannot replicate the OL fault with a simple test track then some time soon you will probably need to post an image of your track plan showing what brand of points are located where and what ones have the point clips fitted and which ones don't. Because if you can't replicate the OL fault on the test track, then that would indicate that something in your layout is faulty. Now it may be that you have got a 'Reverse Loop' inadvertently designed into your layout, but I would need to see your track plan to confirm if that was the case. Reverse Loops inherently create a short circuit.

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[Anton Stedman]

It would be difficult to show the layout in photos as it is located in the loft. However, I have got the SCARM track planner software so I would be able to draw up the layout of the track on this (I did go by a track plan to structure the layout but a lot of changes had to be made so my old track plan on SCARM is not the same as my current layout). 

I will make another track plan using SCARM and put it on this forum ASAP, unless you have any other ideas. 😆

[Anton Stedman]

OK, if your layout is not pinned down and can be taken apart, then by all means use those track parts, just make a very simple circle or oval out of basic straights and curves and exclude any points and scissor cross-overs.

Thanks for the help so far!

Will try to make the test track sometime tommorow. 

[Howbi]

As I have mentioned before on this Forum, Bachmann provide a choice of standard points, i.e. Isolating and Non-Isolating.......the non-isolating versions negate the need for point clips........I would have thought that Hornby would have introduced these before now considering how many posts have arisen over the past few years concerning the viability of the point clips..........HB

[Chrissaf]

A screen capture of a SCARM design would be fine. The 2D display not the 3D one.