Cable requirements for external block detection

Airbuspilot

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We are planning to partially automate a garden layout using the ZIMO MX 10 and StEin units for block detection and iTrain for automation.

The plan is to use single core 2.5mm solid copper cable with crimp connectors onto Massoth single screw track connections as feedback from each block to the StEin. (I have discussed with Split Jaw products re their connectors, I like the idea but between shipping, import and VAT they are expensive) The cable will be protected in a small diameter flexible tube as used by electricians in new buildings. The tubes will be laid on the surface and covered in a thin layer of gravel. The tubes will not be moved but may be subject to some disturbance. Minimum length of cable will be around 25 meters (80 Ft) max length around 45 meters (150 Ft).

I tried using solid plastic conduit but it doesn't work well as any movement moves the complete pipe, it would work if buried properly but this is not possible.

Question No 1 solid copper or multi core cable?

The cables will be Radial from a point around 20 meters from the base station / StEin units which means cables bunched together for around 20 meters. The bunched cables will follow a single track access ramp to a garage storage area where the cables pass through a wall and under the base board. There will be 14 separate cables bunched together either in one bundle or in smaller bundles.

Question 2

As all cables are carrying the DCC signals will we have a problem of interference between the cables when bunched over a fairly long distance?

Robin
 

PhilP

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My two-penneth:

Unless you are passing significant amounts of current, when you need to consider voltage-drop, then 2.5mm cores will be overkill.
Dropping to a smaller cross-sectional area will save you money.

If you are intending to use the 'corrugated' flexible conduit?
Then you will find that the cores will 'snag' a little, as you drag/push them through..
ALWAYS!!
Leave a draw-wire, in every run of conduit.. And, replace it / pull in another, when you use it.

You may find semi-flexible irrigation piping, is cheaper, more forgiving (see comment above) available in a larger diameter, and a lot more UV resistant.

If you are running 14 cables, seriously consider two runs of conduit!
Unless you can pull several runs at the same time, you will find that it soon becomes difficult to pull additional cables through..

If you are using single (layer) insulated cables, there is a greater chance of the insulation being 'burnt' (rubbed, friction) through, as you are running additional cables..
You can get lubricant to help with this, but it is messy, and makes gripping / securing cables to draw-wires, difficult. - So we prefer not to use it. :rolleyes:

Single v multicore:

Perceived wisdom is, solid for 'fixed' cabling, and multicore where you need the cables to withstand regular movement.
Multi, will 'flow' round bends, and be a little easier to pull, but unless you have a bundle, you will not be able to 'push' it through, like you can with solid cores.

Always leave enough slack, so you can re-terminate a bad connection / corroded cable!

Label, and document, everything. BOTH ends.
A local copy (in connection boxes) as well as an overall master, is a good idea..
Damp WILL affect the remote copies, and they may be munched by snails etc.

Have fun!

PhilP
 

Airbuspilot

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My two-penneth:

Unless you are passing significant amounts of current, when you need to consider voltage-drop, then 2.5mm cores will be overkill.
Dropping to a smaller cross-sectional area will save you money.

If you are intending to use the 'corrugated' flexible conduit?
Then you will find that the cores will 'snag' a little, as you drag/push them through..
ALWAYS!!
Leave a draw-wire, in every run of conduit.. And, replace it / pull in another, when you use it.

You may find semi-flexible irrigation piping, is cheaper, more forgiving (see comment above) available in a larger diameter, and a lot more UV resistant.

If you are running 14 cables, seriously consider two runs of conduit!
Unless you can pull several runs at the same time, you will find that it soon becomes difficult to pull additional cables through..

If you are using single (layer) insulated cables, there is a greater chance of the insulation being 'burnt' (rubbed, friction) through, as you are running additional cables..
You can get lubricant to help with this, but it is messy, and makes gripping / securing cables to draw-wires, difficult. - So we prefer not to use it. :rolleyes:

Single v multicore:

Perceived wisdom is, solid for 'fixed' cabling, and multicore where you need the cables to withstand regular movement.
Multi, will 'flow' round bends, and be a little easier to pull, but unless you have a bundle, you will not be able to 'push' it through, like you can with solid cores.

Always leave enough slack, so you can re-terminate a bad connection / corroded cable!

Label, and document, everything. BOTH ends.
A local copy (in connection boxes) as well as an overall master, is a good idea..
Damp WILL affect the remote copies, and they may be munched by snails etc.

Have fun!

PhilP
H
My two-penneth:

Unless you are passing significant amounts of current, when you need to consider voltage-drop, then 2.5mm cores will be overkill.
Dropping to a smaller cross-sectional area will save you money.

If you are intending to use the 'corrugated' flexible conduit?
Then you will find that the cores will 'snag' a little, as you drag/push them through..
ALWAYS!!
Leave a draw-wire, in every run of conduit.. And, replace it / pull in another, when you use it.

You may find semi-flexible irrigation piping, is cheaper, more forgiving (see comment above) available in a larger diameter, and a lot more UV resistant.

If you are running 14 cables, seriously consider two runs of conduit!
Unless you can pull several runs at the same time, you will find that it soon becomes difficult to pull additional cables through..

If you are using single (layer) insulated cables, there is a greater chance of the insulation being 'burnt' (rubbed, friction) through, as you are running additional cables..
You can get lubricant to help with this, but it is messy, and makes gripping / securing cables to draw-wires, difficult. - So we prefer not to use it. :rolleyes:

Single v multicore:

Perceived wisdom is, solid for 'fixed' cabling, and multicore where you need the cables to withstand regular movement.
Multi, will 'flow' round bends, and be a little easier to pull, but unless you have a bundle, you will not be able to 'push' it through, like you can with solid cores.

Always leave enough slack, so you can re-terminate a bad connection / corroded cable!

Label, and document, everything. BOTH ends.
A local copy (in connection boxes) as well as an overall master, is a good idea..
Damp WILL affect the remote copies, and they may be munched by snails etc.

Have fun!

PhilP
Hi Philip

Both solid copper and multi core 2.5 mm are about the same price, 30 Euros / 100 m which is not so bad. For some reason the flexi tube we have here does not have pull wires the electricians use a tracer which seems to work OK, its cheap and lasts a lifetime.

I plan to use small diameter flex tube for each individual radial wire but the idea of semi flex water pipe for the bunched parts seems like a good idea and probably easier to fix. I planned to use several tubes to reduce the number of wires in each of the bunches. The water pipes will survive the Cyprus sun better as well.

I'm not sure if I would consider the radial tubes along the floor fixed or not, there will be some movement certainly but limited.

Robin
 

PhilP

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I would say your installation is 'fixed'..

You put a draw-wire in yourself..
Either a spare/gash run of your cable, or the synthetic builders line, is good.
A 'fish' is a flat spring-steel tape used for the first 'pull' of your cables..
If the run is straight(ish) and not too long, you can use a set of fibreglass cable rods..
A quality set will last you, cheaper ones are less flexible (snap) and the threaded ends can pull off. - Obviously when things are tight, and at their most inconvenient!

PhilP
 

Paul M

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You could try some multiform cable, as above, or SWA which will give you flexibility and security, but expensive