Electro frog points isolation on the uttering ton light railway

[38thfoot]

Hi,

Started a separate thread from my layout thread for a couple of electrical questions.

I have a goods yard in which a y point connects directly to a mainline point off the main running line.  Given that I know electro frog points are fed from the toe end with the exit end isolated do I need to isolate the y point from the loop point that feeds into it or do I leve it electrically connected to the point feeding into its toe but then isolate both exits as normal?

Its the right hand side of the plan.


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Cheers

38

[Hugh Norwood]

I think you'll require 4 feed places and 1 isolation place.

[38thfoot]

But where?, does the yard point need to be isolated from the loop point it runs off?

38

[Hugh Norwood]

Darn - I made a mistake.

I think this will work...
Obviously the isolating breaks can be "slid" along their respective pieces of track...
F= feed, I- isolating break

[Alan Feldon]

Do you really need the reverse point to the right of the front loop?
If you run two sidings running right of the loop (as you have on the left) then you can cut out the isolating and feed on the plan.
I agree totally with what Hugh has posted

[38thfoot]

The reverse junction is for the engine service area with coal and water on the base of the Y and the shed on the kick backed bit, I toyed with just having two sidings but didn't want it to be symmetrical, when I get round to scenery there will be a reason why the shed wouldn't fit!

Can I confirm that you don't believe I need to isolate the yard point from the point that feeds it from the loop?
Won't it always be live in that case?

So far I have isolated the two front loops completely so both loop lines will have a feed.

Also the storage loops are set track insulfrog, are they not self isolating and therefore don't need insulating fishplates?

Cheers

38

[Hugh Norwood]

I've revised the pic by numbering the points.
I assume you are talking about Point No2?
If so, it is powered only when point 1 is set to it.
You do not need to have a separate feed to the "front" loop as it can be fed from either Point 3 or 6. (depending on where you put your isolating break.

Hope this helps.

I can't advise on insulated frog points as I have no experience of using them.

[B.Meldon]

When working out layout wiring I always draw the layout out with both rails on the drawing. This way it become obvious where to place the track feeds and insulators.

Obviously it is also a lot easier to do this before you lay the track as adding the insulating fishplates after the track is laid is difficult.

If you are using DC (not DCC) you will need to wire the layout so that the points isolate the tracks they switch. So just adding an extra feed from your controller to the loop and the points all fed from the toe again from a feed from the controller will not do this as the loop and at least one of the sidings will stay on all the time.

If I get a chance I will draw your track plan out and post it on here.

Brian Meldon




Brian Meldon

[Hugh Norwood]

When working out layout wiring I always draw the layout out with both rails on the drawing. This way it become obvious where to place the track feeds and insulators.

I agree totally

If you are using DC (not DCC) you will need to wire the layout so that the points isolate the tracks they switch. So just adding an extra feed from your controller to the loop and the points all fed from the toe again from a feed from the controller will not do this as the loop and at least one of the sidings will stay on all the time.

I've read that several times and I still don't quite understand you, Brian! Unless you mean that the various feeds should each be switchable...

[Graeme Dunbar]

It might be worth considering what train movements will take place, how many locomotives/trains will be on the tracks and where they will be "parked" when not moving. Instead of thinking of the power following the point settings, it is possible to think of where trains/locos will stand and need to be isolated from power. In a way, isolated blocks represent the signals (real or imaginary).

The capacity is at least four trains, but you cannot run an engine round a train in the station without one of the trains in the storage loops also moving. I would be inclined to put an isolating switch on the storage loop area. Being me, I might isolate the three separately, just in case I set the points incorrectly.  

If a significant amount of shunting is planned using the inner station loop and the sidings then it might be worth considering, or thinking to the future possibility of two controllers, one for the main and one for shunting. (This would be me "playing trains" rather than running to a timetable: letting one train crawl slowly round the outer loop while I shuffle wagons in the sidings and inner loop.) If it was an exhibition layout with two operators, one could control the through trains whilst the other "noodled" in the sidings.

[Hugh Norwood]

After some mulling over (and a trip to the shops and back) - I forgot to say that the four feed points I put on your diagram should not be just connected together since as Brian says you'll still get unwanted movements.

Each Feed should be from a switch; so you have Controller - switch - Feed.
My layout has four feed points each with its own switch on the control panel. These switches also allow me to select one of two controllers, so the dockside (for instance) can be shunted while trains still go round the main loop.

[38thfoot]

Thanks for the replys, I now feel confident to go further.

At present will only be a single controller but I'll wire up for future cab control with spdt switches just in case.
I've already used isolated joiners on the mainline loops so both or either can be turned off/on.

Many thanks

38

[Gerhard Novak]

As I am currently also started to lay track on my baseboards I think there is one thing to add: Especially for longer sidings or for the 3 sidings on the right side of your track plan: You can add a second switchable zone to avoid that any train will run into a point which is set for another route - with electrofrogs this will lead to a short circuit. To avoid that make an insulated zone on the same rail where you have already the insulating fishplate. The length of this insulated section should be a bit longer than the longest locomotive you are using. You will need another pair of contacts on your point motor - which may be there anyway - depending on what point motor you are using. You have to wire it up in a way that the section is dead when the point is set for the other route.

If you have done so you can drive now with a locomotive against the wrong set point - and the locomotive will stop in the dead section - but you will not create a short circuit. For me - as I wire up for DCC - this is important as the chance that one train is running and another one is shunting is bigger than on analogue controllers. But even with analogue controllers - if you can avoid short circuits it is better for your equipment, also not to forget for the wheels of your locomotive.

If I was not too clear with my verbal description I will show a picture in the evening. Now I have to finish my coffee break and get on with my work.....

[B.Meldon]

This is the way I would wire the layout. The points will isolate the sidings and the loops when switched the other way so no need for section switches.




Yes it is true that you will get a short if you try to run the wrong way through a point, but that would de-rail the train anyway.

I would also mention that the point blade to fixed rail electrical switching in the points is not very reliable and I would recommend using frog polarity switches on all the points.

Brian Meldon

[Gerhard Novak]

I think the derailment problem will happen only to coaches and trucks as the locomotive will create the short and stop before derailment. And I have to say I like neither derailment nor a short circuit. :-) I am in favor of soft sprung point blades - so if a coach is heavy enough it will rather open the blades then derail. Of course something like a small V-tipper or similar will get derailed as they are too light.
I also recommend frog polarity switches as the slightest particle such as grass fibers or similar can disturb the electric contact between blade and rail.