DCC shorting on Peco Double slip

[KC Jones]

Hi All

I too have an intermittent shorting problem with some wheels arcing on the frog of a peco double slip and have photographic evidence to prove where it occurs. some wagon wheels shut down the DCC as they cross but when I was running a hornby class 58 on DC I noticed a spark so I set about getting it on camera and succeeded on first attempt. The trouble is both sides of the double slip are live at all times ie no switching with the point blades to insulate the oposite frog rail to the one running on. 

Is there an easy fix for this as it is not like a normal point frog, 

 Tried to upload an image but the upload window said the filetype is not allowed and cant find what filetype is allowed.

 

Regards KC J

[Chrissaf]

Supported file types are .JPG and .GIF. However be aware that as a relatively new poster, images need to be approved by the forum administrator and won't appear straight away. Use the Black&White hill icon (to left of smiley face) to upload your images.

[KC Jones]

Hi All

Found the problem with file type

This is the moment the short occures just on one wheel of the clas 58 pulling eight tanks all with metal wheels. Running on DC but it is enough to knock out the DCC to a short with other wheels as they pass over the frog.

/media/tinymce_upload/5833ca2b421f28ecddc6e011979b267f.jpg

This double slip is insulated from all adjoing track and has its own feed from control panel as you can see the IRJ's

Regards KC J

[KC Jones]

Thanks Chrissaf.

Duly noted and understand.

KC J

[St1ngr4y]

Hi KC,

Have you checked the back-to-back measurements of the wheels of your vehicles?

Ray

[Chrissaf]

I use Peco track. This point of shorting out is in my opinion a Peco design and manufacturing tolerance issue. The two converging frog rails can on some points have less insulation between them than others. Rolling stock wheel profiles can have a bearing on this as well as flatter profile wheels can easily bridge the two converging frog rails and cause a short. See wheel profile A in my graphic below. Wheel profiles more akin to B tend not to short out.

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See my graphic below that helps to explain what I am trying to convey. The converging rails in the example photo are relatively far apart. I have seen some Peco point examples where one needs a magnifying glass to actually see any gap at all, they are so close together. This is not an issue with Peco Electrofrog points, if wired to use switched frog power, as in that scenario the two rails are electrically the same potential anyway.

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/media/tinymce_upload/d24d86cdf3cbce675d710b228d282bcb.jpg

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[St1ngr4y]

Hello again,

I thought the Peco double slip code 100 was an Insulfrog. Have you wired it in some way to make it into an electrofrog?

Ray

[Chrissaf]

Ray,

I read it as KCJ is running both DC and DCC on his layout. This slip is where the two DC and DCC layout sections meet and that he has isolated the point via a control panel switch so that he can select either DC or DCC running on it. However, because of the short between the converging frog rails, the DC section of layout is being bridged to the DCC section of the layout.

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Of course I might have completely misunderstood KCJ's posted text and be talking complete dogs dangly bits.

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Note to KCJ. As you can see since your wiring appears at first glance to be non standard. It will not make it easy for members to offer solutions unless you describe in detail exactly what non-standard modifications (if any) you have performed.

[RDS]

If you have both DC and DCC connected to the same layout (even if you think they are separated by insulated joiners), I am not surprised you have sparks.  You cannot connect DC and DCC on the same track.

[KC Jones]

Hi All.

Thanks for replies so far,

@st1ngr4y, yes the B2B measures checked and all good, the peco is insulfrog and feed wired to the two stock rails from control panel. the spark can only be seen when on DC at near full speed thats how i got the pic, when on DCC there is no spark it just trips the short on both the Elink and The Dynamis, 

@Chrissaf, the double slip is not modified in any way. My layout has a control panel that selects all separate sections of track as it has always been to run several trains on the same track with DC, each section has a DPDT Centre off switch connecting either DC or DCC controlers. all can be used at the same time with no conflicts with a little disipline, The layout works and runs great except for some wheels on the double slip, All parts of the double slip are live at all times irespective of blade/train direction, unlike points where the oposing frog rail would be dead, point clips not fitted.

@RDS Yes DC and DCC can be controlled at the same time but as you say not on the same track, my control panel wiring wont allow two controllers to conect to the same section of track at same time, I think I have best of both worlds, run anything at the flick of a few switches.

I cant think of a simple way to eliminate this shorting unless I treat it like an electrofrog by cutting the fine wires accross the underside of the frog and add some more switching but no point motors fitted to provide switching. 

Regards KC J

[RDS]

@KCJ

Yes, I understand.  The usual way that members run both DC and DCC is that they have a DPDT switch that covers the whole layout, so the whole layout, not just individual sections, becomes DC or DCC.  As I have read it, one section of your track could (in theory) be DC and then the next section could be DCC.  If that is the case, the front part of a Loco could be DC and the rear half, DCC. (unless I have read your post completely wrong).

[KC Jones]

RDS Yes you could be right only that the track the train is travelling on will either be DC or DCC depending on the loco I am running. For this experiment all of the UP Main line is running on DC switched accordingly. non of the other tracks on the layout was alive with anything (all other switches in centre off) therefore no possible conflict of polarity,

My layout can run with Two analogue controllers for the UP and Down main lines with the dynamis running the branch line and storage/fiddle loops and the Elink running the loco sheds Diesel/steam, All at the same time with no conflict problems, I agree it could become very complicated if I were to throw a few switches at random, but then the only short would be where a loco running on DC passed onto DCC live track or visa versa. this has only happend while I was getting used to operating and during modification of the circuits, Wires/Track.

I only put the double slip in the station throat area for more function of operation and to be more in keeping with realistic track plans,

That'll teach me as it is a recent allteration,

Regards KC J

[Gearoid]

Folks,

I would like to ask a arelated question. I have just installed my first double slip - insulfrog - on a DCC layout. Will I need to install a DPDT switch?

Thanks

[Chrissaf]

Probably not....... as your layout is ALL DCC. The original poster had a highly customised wiring plan that utilised the switches.

[Gearoid]

Thanks Chrissaf