Wiring for two control positions

[drmditch]

My new/reworked railway (see here..http://www.rmweb.co.uk/community/index.php?/topic/105609-rebuilding-a-railway/) is gradually progressing.

 

Because it is actually quite large (19' by 11') and has quite a complex layout, I would like to have two alternate control positions which will have some overlapping capabilities.

 

This is a rough outline diagram:-

 

 

 

This diagram is much simplified, and does not show all sidings, tracks, and junctions etc.

 

My proposed wiring scheme will allow for four major controlled lines (CL), The Red and Black represents the up and down circuits on the lower level. Red will also control the main storage sidings (under the high-level terminus) The Green is the mid-level circuit with it's own storage sidings. The Blue covers the high level terminus.

 

Each CL can only have 'one engine in steam' (or rather under-power) at one time. There is/will be ample provision of isolated sections on each CL and in the sidings. Connections between CLs are fully insulated.

I will provide each line with a 'main power ring' of 1.5SQMM fairly heavy-duty cable, +ve and -ve, with frequent links to the track of 0.2mm conventional 'layout wire'.

All the isolating sections will utilise a SPST switch.

 

It is thus quite possible to have several locomotives/railcars on each CL at one time, but only one can be under power. (I am not looking at using any of multiple unit except possibly for Phenomena, the articulated Sentinel Railcar when I get round to building it!)

 

My old railway used this basic scheme and it worked well. I have most of the switches/motors etc in stock. Subject to adequate labeling it allows for relative simplicity and faultfinding. (At least for me!)

 

The old railway however, being smaller, was controlled from one position only. That only had three CLs, each of which was capable of being powered by one of two controllers, Each CL was connected by a DPDT switch to the required controller.

 

For the new railway, I would like the option of two control positions.

Position 1 will have full control of all four CLs with all details at it's own end (including the storage sidings) and basic control (major routes but not all sidings etc) at the other end.

Position 2 will have full control of it's own end, and just enough control of the terminus and sidings to be capable of running a 'through train'

 

The high-level terminus has points and signals controlled from a local lever frame.

 

Each position will have four controllers.

I would like to be able to switch CLs between controllers using a DPDT switch, thus preventing any chance of controllers being in parallel. However, I can't see any way of achieving this without some very long and inconvenient cable runs.

 

What I'm thinking about is providing each position with DPST switches for each Controller/CL.  These would have to be in an easily accessible and visible situation. Maplins do provide a DPST switch with an illuminated rocker.

Obviously, this does have the risk of inadvertently connecting controllers in parallel.

 

Usually it will only be me operating the railway (I am quite a solitary person) but it would be nice to invite friends from time-to time, any such persons obviously having to work 'under instruction'!

 

I would be grateful for any advice and (informed) opinion!

[BR60103]

I have a layout with 4 control positions (throttles) and a lot of wire running around it.

I am using common rail, so single pole switches are used.

I have one control position that selects blocks for my single track loop mainline and there are some very long wires running from it. A lot of the wire is lampcord which was easily available and came in 4 different colours appearances. (Ours only has to handle 120V). It's overkill, but at least doesn't present resistance problems.

[drmditch]

The  Control 1 position has now been fitted with a panel with a DPST switch for each of the controlled lines, and I've just started with the Control 2 box. 

 

However, if the technical people on this forum will bear with me I have another question.

 

If I create a 16v AC circuit for point motors, can I have two power supplies connected to it, live at the same time; or do I need to provide the same switching as for the 12v DC?

 

(This will be only for points/signals etc - other 16vAC devices from a separate power source.)

[drmditch]

NEVER EVER connect 2 live AC supplies with each other! Nor if one isn't live! 

Thank you. I did ask!

[DCB]

We use a central panel to switch sections between controllers using one rotary switch per section. 4  main controllers can each operate 95% of the layout, and 3 subsidiary controllers control only small areas of which all but one small area can be operated by any of the 4 main controllers.  The 4 Main controllers are at extreme left,centre, extreme right and wander lead positions.

The sections are sub divided as per your layout.

We don't have a bus bar except a partial one on the outside branch.

Two mistakes we made were,  1) Not having an off position on the rotary switches, 4 way 3 pole serving 4 circuits when we should have used 6 way 2 pole.

2) Single isolators on common return.  We should have used double isolators and  DPDT as it leads to very odd wiring when the isolator needs to be on the common return side of the section.

 

Wander leads are great but you get tangled up in them. I swapped the 4 pin DIN plugs on our OnTrack units for Stereo Jack plugs so they pull out in one piece rather than the wires pull out of the din socket as you trip over the damn thing again.  I also use a home made "palm" hand held controller made from a small 2AA battery torch which allows one handed control.  

 

Could Dutch_Master expand on why not to connect two AC supplies?

[drmditch]

I'm currently working on one of the eventual two control panels - having first had to strip down a whole load of switches from the older panels!

Some of these are fairly elderly NATO spare parts, which I was able to purchase from one of my previous (and now non-existent) employers.

 

This is not my favourite part of railway modelling!

 

However, this has given rise to another question, about which I hope some of the knowledgeable people on this forum can advise me.

 

I have built four 'ring-mains' for each of the circuits using a fairly thick (domestic lighting) cable. The main control position has it's Gaugemaster controller connected via DPST switches and wiring which is not quite as thick as the ring-mains, but is thicker than normal 'layout' wire.

 

However, the 'secondary' panel has more complicated switching, and it has not been practical to use the thicker wire throughout.

I have had for some of the links to use the ordinary 'layout' wire.

 

Will this matter?

[kevinlms]

 

Could Dutch_Master expand on why not to connect two AC supplies?

Because they are transformers & step down & also step up. This means if one power supply is on and is say a 240 volt to 24 Volt reduction, putting another similar transformer across it will cause the 2nd to step back up to 240 Volts. If that power supply is unplugged, the plug will be live 240 Volts. A serious hazard if picked up.

OK it won't be 240 Volts exactly, because transformers aren't 100% efficient, but will be close enough and so is dangerous.

 

So NEVER wire 2 transformers in parallel.

[AndyID]

Because they are transformers & step down & also step up. This means if one power supply is on and is say a 240 volt to 24 Volt reduction, putting another similar transformer across it will cause the 2nd to step back up to 240 Volts. If that power supply is unplugged, the plug will be live 240 Volts. A serious hazard if picked up.

OK it won't be 240 Volts exactly, because transformers aren't 100% efficient, but will be close enough and so is dangerous.

 

So NEVER wire 2 transformers in parallel.

Yes, it is extremely dangerous. The voltage will not actually be reduced either. Efficiency only comes into play when current is flowing.