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Wiring for Electrofrog points


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This is really a follow on to my earler posting about fitting points next to each other, and I am pleased to report that I have manged to overcome the loose joiner issue. I have started at the lead-in end of my planned layout, using four Peco Insulfrog SL-87 large curved turnouts, and that has proved to be a big mistake. My three locos are all small three axle tanks and the wheel spacing is such that each of them manages to rest two pairs of wheels on the plastic frog and the insulation spacer beyond the frog, resulting in tediously repetitive stalling. I am, therefore, considering replacing  the turnouts with Electrofrog points, but have never used them before. I have read up about installing them as supplied, or modifying them to create a permanetly powered switch blade, and understand both methods, but none of the instructions explain how power is supplied to the two rails ahead of the frog which are insulated from the frog, without installing a points motor and auxilliary switch, as I do not intend to install points motors I need to know how to wire them directly. So far the only solution I have come up with is to solder a wire to each of the inside rails before the frog and connect the wires with each of the the rails that are in line with them, beyond the insulation. Will that work or is there a better method?

 

 

Edited by David Schweizer
correct confusing information
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Hi David,

 

You have to switch the frog one way or another and so the method of switching doesn't really affect the answer to your question. If you do the live point blades modification then you have to switch the frog externally.

 

The rails beyond the frog can either be electrically connected to the frog and take all power from it, or have their own power feed and be insulated from the frog.

 

Aside:

If you think you might like to use the point blades to switch the frog now but leave open the option to use an external switch later, then there's a simple method here: https://www.rmweb.co.uk/community/index.php?/topic/109951-electrofrog-point-isolations/&do=findComment&comment=4174997 (Read further back for Suzie's written explanation.)

 

 

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As supplied the Peco electrofrogs will work almost exactly the same as your current insulfrog points. The big difference is that they don't self-isolate the non active road. on Insulfrog points the non active switch rail is electrically dead. On an as-bought electrofrog the non active switch rail will be live but at the same polarity as the other rail of the non active route so any trains on that track (assuming no other feed in place*) will not move as both rails are at the same polarity.

 

Hopefully this image makes that clear 

Turnout_Plan_SL-87.jpg.f3a4975c54c357756771e7df40163931.jpg

 

The power supply to the outer rails is shown as red and black.  All the area shown as green is electrically one lump. The point blades against the stock rail act as a switch in themselves just like they do in insulfrog points, So when the point is in the position shown this is what the polarity actually looks like.

 

Turnout_Plan_SL-87a.jpg.00ab436da4dd57eede6589714d753dd5.jpg

 

As you can see, the lower route has one red rail throughout and one black rail throughout and trains will move on it as normal. The upper route has two red rails and no trains will move on it.

 

If you lay your points as they are bought then they will work with no extra switches.

 

BUT (and it's a big but)

 

That point blade to stock rail contact is not very reliable, and the non selected point blade is at the opposite potential to its stock rail, this can lead to short circuits if the back of a wheel touches it.  For these reasons it is recommended to modify electrofrog point to do away with that reliance on point blade to stock rail contact and to remove the short circuit possibility.

 

To allow this Peco give us little wires welded underneath the rail below insulated sections between the frog and the blade roughly where the tiny blue lines are in this picture. 

Turnout_Plan_SL-87modded.jpg.71f58efe3fb1e525ffc278ee22e87047.jpg

 

These little wires can be simply snapped out with a small screwdriver or cut with fine wire cutters or Zurons. This breaks up all the green area in the first image into three electrical sections. In order to remove the need to rely on that point blade to stock rail contact you can solder link wires as shown between the switch rails and the stock rail, - there are gaps in the sleeper webbing for this - and also now you need to provide an external means of switching the frog itself (for which Peco have a wire that comes from the frog as supplied). You can lay them as bought without this mod and later add a frog switch to remove reliance on the blade contact but it still leaves that problem of shorting against a wheel back mentioned above.

 

*It is the possibility of other feeds reaching the point from the wrong end that is the reason for fitting insulating joiners on the frog rails of electrofrog points.

 

That's all probably as clear as mud!

 

Andi

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I switched to electrofrog for similar reasons to yours, and chose to use Gaugemaster auto frog devices (there are other makes) which switch the polarity of the frog according to direction set. This means the whole frog is either one way or the other, but no matter how wheels pass through the frog, it is the ‘right’ polarity. Of course, using insulating breaks on the two inner exiting rails is essential.

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4 minutes ago, ITG said:

I switched to electrofrog for similar reasons to yours, and chose to use Gaugemaster auto frog devices (there are other makes) which switch the polarity of the frog according to direction set. This means the whole frog is either one way or the other, but no matter how wheels pass through the frog, it is the ‘right’ polarity. Of course, using insulating breaks on the two inner exiting rails is essential.

Those will only work on DCC. I believe the OP is not a DCC user according to some of his older postings though that may no longer be the case of course!

 

Andi

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Just now, Dagworth said:

Those will only work on DCC. I believe the OP is not a DCC user according to some of his older postings though that may no longer be the case of course!

 

Andi

True, although I’m not sure I spotted whether it was D.C. or DCC.

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Thanks for the swift replies, the diagrams shown are very similar to several I have already downloaded. I am assuming from the comments that the electrofrog points will work in exactly the same way as Insulfrog points if I do not use insulated joiners on the two inside points rails, but if I do use insulated joiners, I have to provide a supply to the rail beyond the insulated joiners. If this is correct I am still not clear where that supply can come from and whether I will need to use switches

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11 minutes ago, David Schweizer said:

Thanks for the swift replies, the diagrams shown are very similar to several I have already downloaded. I am assuming from the comments that the electrofrog points will work in exactly the same way as Insulfrog points if I do not use insulated joiners on the two inside points rails, but if I do use insulated joiners, I have to provide a supply to the rail beyond the insulated joiners. If this is correct I am still not clear where that supply can come from and whether I will need to use switches

What are these points leading to David? Are they dead end roads or parts of loops?

 

Andi

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46 minutes ago, Dagworth said:

What are these points leading to David? Are they dead end roads or parts of loops?

 

Andi

 

Hi Andi,

The points are all leading from a single dead end to six dead end sidings  over something less than two metres, with one dead end extending less than another metre, and my plan was to only have one power feed on the single dead end. I have the potential to construct a single loop from one end to the other, with no points but that may never happen.

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If the points all go to dead ends then you can do exactly that, one feed on the single line.

If you create a loop then put an insulating joiner on the frog rail of the loop line, the power will come all the way around the loop and no additional feeds will be needed.

 

Andi

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41 minutes ago, Dagworth said:

If the points all go to dead ends then you can do exactly that, one feed on the single line.

If you create a loop then put an insulating joiner on the frog rail of the loop line, the power will come all the way around the loop and no additional feeds will be needed.

 

Andi

 

Thanks Andi, There will be a loop (of sorts) at the far end of the longest dead end where the two station tracks will merge into one line, but I can sort that out when the layout trackwork is finished.

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Having studied the diagrams and explanations, I have proceeded with a number of tests. Assuming that the geometary of Electrofrog points is the same as Insulfrog points I have concluded that the minimum 1.5 mm gap between the wheel back and the unselected point blade will ensure that there is no risk of shorting, and as the longest wheelbase on my small four wheel coaches is only 75mm, the angle across the curved rails is negligible. However, I am a cautious chap and in the first instance have decided to buy one set of Electrofrog points as an experiment, and try them out of the box un-modified. If all goes well I will shell out on seven more sets. The next issue will be disposing of eight sets of Insulfrog points, which apart from three pairs of tiny pin holes on the outsides of the sleepers, are brand new. Time for ebay!

 

Many thanks to everyone who has offered advice and information, particularly Andi for his Instructions and diagrams.

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On 21/11/2020 at 16:50, Dagworth said:

That's all probably as clear as mud!

 

Andi

 

Mud  schmud - for me, that's the best explanation of the issue, with the best illustrations, that I've ever seen on here - and I've seen an awful lot over the years!

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18 hours ago, Chimer said:

 

Mud  schmud - for me, that's the best explanation of the issue, with the best illustrations, that I've ever seen on here - and I've seen an awful lot over the years!

Not to rain on anyones parade but it would have beeb helpful to mention  which kind of point was displayed in the pictures :laugh:

 

Then it could have been helpful to point out that Electrofrog points are actually cut on the blue lines, at least newer ones are.

 

Sorry I needed something to do whilst waiting in a helpline queue

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2 hours ago, RobinofLoxley said:

Not to rain on anyones parade but it would have beeb helpful to mention  which kind of point was displayed in the pictures :laugh:

 

Electrofrog points may have changed slightly over the years, but you can fiddle with Insulfrog points to make them work in the same way, but obviously still with a plastic frog.

I did this with about 15-20 Insulfrog points at the club which had been recovered from a layout we are rebuilding.

Why?

Several suffered from blades which wouldn't conduct reliably, causing dead sections. Some members refused to accept this so there was no way I could justify replacing them all.

Modifying them was a free alternative to replacement.

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So far so good,  I have produced some (paper) mock ups and the only remaining issue is the two tracks through the station. Basicly the layout is typical single track K&ESR with all the dead end sidings aproached from one direction. After all the sidings turnouts, the single track diverges into two tracks through the station and then reverts to single track after the station, creating what is basicly a passing loop. The problem is that changing the points at each end of the loop will cause a short, if there is even the slightest amount of power still reaching the track. I am not prepared to risk this so I need to find a solution,  turning the power off before changing the points, and back on when changed may be the easiest solution, but seems a bit primitive. Another solution I have come up with is to isolate a section of each of the inside tracks with a switched connection, but that would entail installing four switches which seems a bit OTT. I have also looked at cutting the two link wires under the rails close to each frog and installing a pair of two way switches, connecting the frogs with the main supply rails, (as per the illustration below), but my simple brain cannot understand whether that would work or not, and it would still involve two switches wheras one switch simply turning the power OFF/ON would seem to be the simplest (if amateur) solution. I think I have answered my own question, but any advice would be gratefully received.

 

image.png.cc2d10528000b503e8dfd1a8b3367a1b.png

 

 

Edited by David Schweizer
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Just provide a second feed to the converged end, it is useful to be able to isolate a loco there anyway. then add two more insulated joiners (SL-11) to the other two rails at the frog end of the turnout.

Its a standard principle with wiring of electrofrog points that the feed must always come from the toe end.

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You're now into the space of "regular" electrofrog design.

 

To prevent shorts, you must put insulating joiners on the rails leading from the frogs - the track beyond those insulating joiners must be fed power independently.

 

Strictly, this is all that you MUST do. But as discussed previously, a design that has both switch rails with the same polarity as the frog is prone to shorting between the stock rail and the switch rail. This leads to the idea of cutting the wires between the switch rails and the frog as in your diagram. This results in the frog needing its own power feed, which must switch polarity when the point is switched.

 

If the point is operated by a point motor, most of these can have a switch that can be used to provide the correct feed for the frog (switch is either built in or can be added as an accessory to the point motor). If the point is operated manually, it is necessary to have some form of mechanical switch which is moved when the point is switched. In the case of DCC operation, it is also possible to use a frog juicer device like the Gaugemaster DCC80, where there is no mechanical switch and the frog polarity is organized through electronic technology.

 

Finally, bonding wires can be added to the switch rails as shown in your diagram, to overcome any poor electrical continuity between the switch rail and the corresponding stock rail.

 

Mike.

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Thanks for the suggestions.  I understand the convention that the power should be fed into the toe end of the points which is the case with the first six points on the layout, but the seventh point is at the further end of the Passing loop, and I was not planning to feed any power into what is a half metre dead end beyond that point.  It is really only there to add some visual realism and provide the facility for locomotives to change ends of the train. I also understand the consequences of allowing negative and positive to meet each other on the same rail, which would happen on the passing loop when changing points if the power was on, and  is why I came up with the idea that the power be turned off while changing the passing loop points. Furthermore it would only involve one switch rather than several, and would avoid the need for complex cicuitry. I would be interested to learn of any technical reasons why such an approach should not be adopted. Just to clarify a couple of points, raised in the suggestions, I am running DC only, and am not planning to instal any points motors. I realise that I am a bit of a novice where model railway wiring is concerned, but I do have a good understanding of 12v power, having worked on and extended a battery powered system on a 50 ft boat where the calculations and circuitry can be quite complex.

 

 

Edited by David Schweizer
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11 hours ago, RobinofLoxley said:

Not to rain on anyones parade but it would have beeb helpful to mention  which kind of point was displayed in the pictures :laugh:

 

Then it could have been helpful to point out that Electrofrog points are actually cut on the blue lines, at least newer ones are.

 

Sorry I needed something to do whilst waiting in a helpline queue

My text did make that clear,



To allow this Peco give us little wires welded underneath the rail below insulated sections between the frog and the blade roughly where the tiny blue lines are in this picture

unfortunately the images I used as the base for the diagrams are the plans that are currently on the Peco website under SL-87/SL-E87/SL-E187 https://peco-uk.com/products/sl-87-turnout-plan

I missed that there is a better one under just SL-E87

 

Andi

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8 hours ago, David Schweizer said:

Thanks for the suggestions.  I understand the convention that the power should be fed into the toe end of the points which is the case with the first six points on the layout, but the seventh point is at the further end of the Passing loop, and I was not planning to feed any power into what is a half metre dead end beyond that point.  It is really only there to add some visual realism and provide the facility for locomotives to change ends of the train. I also understand the consequences of allowing negative and positive to meet each other on the same rail, which would happen on the passing loop when changing points if the power was on, and  is why I came up with the idea that the power be turned off while changing the passing loop points. Furthermore it would only involve one switch rather than several, and would avoid the need for complex cicuitry. I would be interested to learn of any technical reasons why such an approach should not be adopted. Just to clarify a couple of points, raised in the suggestions, I am running DC only, and am not planning to instal any points motors. I realise that I am a bit of a novice where model railway wiring is concerned, but I do have a good understanding of 12v power, having worked on and extended a battery powered system on a 50 ft boat where the calculations and circuitry can be quite complex.

 

 

 

The loco release spur at the end of the platform needs to have power for its whole length because at this stage you can't guarantee what operations you might use it for. You might need to drive a loco to the very far end for some reason so give it equal importance and attention as any other bit of track.

 

It is usual to allow the power to be turned off for the loco release spur separately from the platform track and the run round loop so that another loco can pick up the train in the platform while the arriving loco stands in the spur. (This operation may or may not have happened prototypically but, again, you can't know for sure at this stage if you'll ever need to do that so it's wise to allow for it.)

 

The layout will probably be divided up into sections, each with its own switch on the control panel so that you can control the movements of more than one loco and for fault finding. So it's a very small overhead to add another section switch for just the loco release spur.

 

In that case the typical arrangement might be something like this:

 

DS2.png.a90dcc84663a3908c54c44caecf448f4.png

 

  • Only two switches are needed on the control panel for this area.
  • There’s no need to turn off the power to change the points.
  • Notice that it doesn't matter in what combination the points are thrown (or how the frogs are switched), the insulators in the frog rails prevent shorts through the rails. You may get a short if you drive a loco over a point that is set against it but that's a different matter.
  • The platform and run round tracks take their power directly from a switch, not relying on point blade contact, thus improving reliability.

 

Edited by Harlequin
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Thanks for that Phil. Just one question. Are the four locations marked - To switch labelled "Platform and Loop" supplied by one (presumably double pole) switch, if so, does that switch source it's power from the Controller? Well two questions, Does the power supply to the switch labelled "Loco Release Spur" also come from the controller. To clarify my earlier post, it is a one section end to end layout, with a total length of less than 3metres without points motors, The illustraion I supplied was perhaps confusing because it included reference to points motors, wheras I meant to only show the control switches.

 

Just to muddy things, prototypically the passing loop was hardly ever used, except to store spare carriages, so it would probably be easier to include the converging loop points for visual realism, but use insulating rail joiners at both ends of those points . That way I would not have to worry about any switches, but could modify it to be live at some future stage, which given my age will probably never happen. In the first instance the only real reason I embarked upon a layout was so that I had somewhere to display, and use, the prototypical K&ESR locos and rolling stock I have built, and continue to build.

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If I read this correctly, your platform road, run round and sidings arrangement means that for a train arriving at the station, all points are facing except for the one at the far end of the run-round loop.  If that's right, you are really only going to use one electrical section, and you are prepared to rely on point blades and fishplates for conductivity, you can use unmodified electrofrog points, only feed power to the tracks somewhere before the first point reached on arrival, and just use 2 IRJs, on the frog rails of the point at the far end of the loop.  Given your last sentence, I might be tempted to do just that for simplicity.

 

At first glance I thought you would have to have a power feed to the track beyond the run-round loop because of the IRJs, but in fact both rails there will be live provided the points in the throat are set appropriately (i.e. for platform or loop, and not leading to any other sidings).  I would be tempted to add feeds to both rails there, however, at the cost of adding a few more IRJs (at least 2, but that would depend on the sidings layout).

 

Wrt your questions to Phil .... yes, and yes.  But he is proposing a multi-section arrangement.

Edited by Chimer
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1 hour ago, David Schweizer said:

Thanks for that Phil. Just one question. Are the four locations marked - To switch labelled "Platform and Loop" supplied by one (presumably double pole) switch, if so, does that switch source it's power from the Controller? Well two questions, Does the power supply to the switch labelled "Loco Release Spur" also come from the controller. To clarify my earlier post, it is a one section end to end layout, with a total length of less than 3metres without points motors, The illustraion I supplied was perhaps confusing because it included reference to points motors, wheras I meant to only show the control switches.

 

Just to muddy things, prototypically the passing loop was hardly ever used, except to store spare carriages, so it would probably be easier to include the converging loop points for visual realism, but use insulating rail joiners at both ends of those points . That way I would not have to worry about any switches, but could modify it to be live at some future stage, which given my age will probably never happen. In the first instance the only real reason I embarked upon a layout was so that I had somewhere to display, and use, the prototypical K&ESR locos and rolling stock I have built, and continue to build.

Yes, and Yes.

 

You might have section switches on your end-to-end so that you can shunt at one end while locos at the other end don't move without having to set the points against them. Even if the entire layout is one section I think it would still be wise to isolate the loco release spur and feed it through a switch. It's a very simple thing to do and gives you some insurance if your plans change in the future. (Just having a layout that you can run stock on changes things!)

 

The wiring could be more minimal than I showed, as Chimer suggests, and I did think about leaving out the feed at the toe end of the loco release points but then it gets more complicated to explain and understand. The drawing shows the most obviously understandable solution - the one that most people would be comfortable with.

 

Edited by Harlequin
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