Point Motor Wiring layout

[brober]

I am about to embark on the electrification of the point work on my layout. Before I delve into it I have drawn up a diagrammatic version of the layout with my proposal for the wiring as I see it. I would be grateful if the knowledgeable and helpful worthies on this forum would have a quick look over what I am thinking about and let me know if I am way off the mark or perhaps have just got it right. Please make any suggestions as to how it could be simplified/ improved and if there are any glaring errors that need fixed.

Many thanks in advance

Bruce

[Roger (RJ)]

It would help if you uploaded a diagram!

[Flashbang]

As Rog (RJ) says a posted drawing would really help

However, we need to know the type of point motor.. Solenoid, Stall motor, Servo motor etc. Most likely they are to be a solenoids such as Hornby R8014/R8234 - Peco PL10/PL11 or Seep PM range etc
For conventional operation you will need a suitable power supply for the solenoids, this is frequently around 15-16 volts AC at 1.0Amp. DC can also be used but really needs a higher DC voltage of around 19 to 22 volts DC ex laptop power supplies are frequently used.

Next comes the means of operation per point - Passing contact lever. Non locking sprung to centre off toggle switch. Push to make non locking press buttons (2 needed) or Stud and Probe are the usual analogue switching methods.
Note; if using toggle switches they must be of the type that doesn't lock On. They are usually referenced as (On)-Off-(On) where the bracketed On cannot remain On when the toggle switches lever is released - it returns to the centre Off position under its internal spring.

Wiring throughout needs to be at least 16/0.2mm (20AWG or 0.5mm2) e.g. 16/0.2mm equipment wire. (Be cautions of some so called "Layout Wire" sold by some retailers, as this is often 7/0.2mm and is really too small for 100% reliable operations where solenoids are used).

Finally, a Capacitor Discharge Unit (CDU) is a good to have item, normally only one CDU for the whole layout is needed and is wired immediately after the power supply and before the first operation lever or switch. Note A CDU does not work well with the Hornby R044 Black point lever but does work with all other passing contact/momentary levers or switches.

[brober]

Thank you Brian. I think I have already taken onboard your advice. I was just looking for a confirmation that I had understood it all. I tried uploading a pic of the track layout and a pic of the wiring i am proposing but neither would attach to the post. I would be happy to try again if someone can tell me how to do it successfully.

[Bufferstop]

The Peco passing contact lever switch manages to sit in two camps taking the benefits of both. Firstly it's a lever looking like a miniature of the real thing. More importantly it contains a miniature version of the first Hornby-Dublo passing contact switch, which doesn't reactivate the previous selection before firing the one you want. The old H-D one involved connecting the lever and the moving contact with a spring, I assume the Peco one is similar but it looks far less likely to survive dismantling to take a look. Hornby Dublo later modified their design which was to the type that doesn't work well with CDUs. Their are two ways of determining which H-D version you have. The body of the original version was moulded in hard red bakelite which often had minor chips on the hard edges, the newer design being moulded in polystyrene which had smoother edges. You could hear and feel the contact moving slightly after the lever in the original design, whereas with the new design all you could feel was a very slight change in friction as it moved across the two fixed contacts.
There was a slight safety issue with the newer design, shared by the Triang designed one, it was possible for the lever(s) to be accidentally nudged into contact with the first fixed contact, with no sprung return the solenoid coil(s) could overheat and burn out. Not only is this deadly for the solenoid the fumes released were not very conducive to good health.

[brober]

I have discovered that the images I was trying to upload were "greater than 2Mg" and that is why they failed, even though they were max 1.75Mg each! I have now created low intensity pics which appear as if they will upload now. They are not as clear as I would like but hopefully sufficient for your review. If you need any clarification on any of the info please just ask and I will advise.

[Flashbang]

Hi
Looks like you've nailed it It looks correct.

The only thing I would add is if any of your point switches move two or more solenoids at once - cross over pair of points etc and especially as you're using Seep PM1 solenoids then I would recommend increasing the return wire size. Use as a minimum 24/0.2mm or better would be 32/0.2mm or if its easier double up the return 16/0.2mm wires - 2 x 16/0.2mm wires connected at each end together then tap off this for all local returns.

[brober]

Thanks Brain. Much appreciated and also the comments from Bufferstop. One point for clarity.... when you say the "return wire" are you referencing the black wire I've shown connected to the -ve terminal of the CDU that picks up all the local black wires?

With regard to the connection of the "local return wires" (if they are in fact the black wires from the point motors!) is there a smart way of connecting these into a "wire in" to "wire out" terminal block and the local black wire to interface with the through wire? I'm not sure I made that very clear but in simple terms "like a T-Junction". I don't want to solder connect them as it would mean working under the track board lying on my back. I have used splice connectors in the past but would like to move away from them if I can find a better alternative.

[Flashbang]

Hi

The Common Return wire is perhaps sometimes called a single wire return to the CDUs Negative output.

If you increase the wire size of the common return wire to say 32/0.2mm or double up to 2 x 16/0.2mm wires, all you've done is make that one wire return wire a larger size. Then tap off this in a smaller (16/0.2mm) wire to each Seep motors "C" connection.

[brober]

Thanks. Understand now.

Bruce

[pete12345]

The neatest method for making a terminal block is to use DIN rail terminals which can be electrically joined with a bus bar. Probably overkill but it does make for a reliable installation.

An alternative is to use the common screw terminal blocks, and join all the terminals on one side with loops of wire. The individual connections then all go in the other side.

[Flashbang]

<SNIP>
An alternative is to use the common screw terminal blocks, and join all the terminals on one side with loops of wire. The individual connections then all go in the other side.

Like these examples... https://www.brian-lambert.co.uk/Electri ... stribution

[brober]

That's an interesting suggestion. I will give it some thought.

[brober]

When wiring up a pair of points forming a cross over activated from a single switch is the paired wiring to be to the same terminals on each motor or does one have to be reversed? and... does the common return from each motor have to be paired before connecting to the main return bus?

[Flashbang]

For two Seep PM1 to move correctly together will depend on several things...
A) If the two Seeps are facing the same way under the baseboard, then wiring tabs A & B are the same on both. If one is 180 degrees around from the other then A on one will become B on the other.
B) "C" on both regardless of their physical position connects to the master (Common) return wire - One wire from each motor runs a short distance to the master return wire where each connect onto this larger wire size Common wire
C) Do not link motor 1 to motor 2, almost certainly the first motor will grab all the power! It is better to wire each individually from the one switch/lever to the two motors A & B tabs. But try and make these four 16/0.2mm feed wires all roughly the same length as near as possible.
D) Seep PM1 to PM4 range are notorious for needing to be 100% aligned correctly under the point. So do ensure this and also do not over tighten them either.
They are also noted for their large current needs. Hence my recommendation for 16/0.2mm wire to each motor and a larger master (Common) return wire. A large uF value CDU will help considerably