Future proofing cables in a trench

Future proofing cables in a trench

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mel

Original Poster:

10,168 posts

276 months

Tuesday 20th September 2016
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The garden is currently looking like a First World War battlefield and I've got open trenches ready to have cables and ducting (50/63mm diameter) dropped in this weekend but I just want to check I'm not forgetting anything obvious.

The supplies go to a new Garage in one direction and Garden Office in the other, for various drainage reasons I'm not putting a water supply to either but both are getting what I think I might need now and hopefully in the future for power and data:

Garden Office - This is used as an Office as O/H works from home a couple of days a week and dials into work, it's 5.4x3.6m and will have a couple of desks and computers, occasional sofa bed, fridge, TV, coffee machine, lighting and power. Speed of internet access is important here but we top out at about 70Mbs into the house)

1x 6mm four core armoured on 32 Amp breaker (it's 4 core as I had some at work left over)
Conduit with:
6x Cat5e
2x spare pull cords
1x cannoned satelite coax

Garage - To be used as a garage/man cave it's 6x6m and will have a wireless access point, TV, benches, tools, sofa, and bloke stuff, plus backup 7KVA generator in a separate lean to that feeds back to the house

1x 16mm 3 core armoured as main supply
1x 6mm 3 core armoured as backup generator return to house
1x 6mm 3 core armoured for dedicated electric car charger or PV array (haven't got either, no immediate intention to get them but who knows how things will change)
Conduit with:
8x Cat5e
2x spare pull cords
1x cannoned satelite coax

I've no idea yet if I'm going to have ip CCTV, alarms, automation, or anything else but have I allowed for enough "stuff" do you all think? Should I also pull some sort of fibre optic cable to both (don't understand the different types but will future internet access need them?) Do I need more Cat5e or can I rely on lots of stuff using the WAP's and reserve the cables back to the router for what needs better speeds? Do I really need the coax or is this now old and dead technology? Should I also run some phone cable or dedicated alarm cables or just rely on the Cat5e?

I'm working on the logic that the trenches are open and now is the time to pull everything through in one run rather than risking entanglements at a later date. Oh and the power and data will be separated by shielding and about 50mm distance nut in the same trench.

bony_13

166 posts

98 months

Tuesday 20th September 2016
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Is it possible to give more than 50mm seperation between power and comms?

I confess I am no expert, but I've worked in civil engineering for a while now and I know we always try and separate them by more than that (although we deal with higher volts and amps than your project I would guess).

Pheo

3,345 posts

203 months

Tuesday 20th September 2016
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Ideally CAT5e does have the separation but I don't think it'll kill you.

However I'd probably go the extra mile and get decent quality copper CAT6. I'm also half wondering how much a run of fiver would be for that length for future proofing. But copper probably plenty especially if you have the WAPs and hardware on different runs / dedicate circuits to specific high bandwidth applications...

mel

Original Poster:

10,168 posts

276 months

Tuesday 20th September 2016
quotequote all
bony_13 said:
Is it possible to give more than 50mm seperation between power and comms?

I confess I am no expert, but I've worked in civil engineering for a while now and I know we always try and separate them by more than that (although we deal with higher volts and amps than your project I would guess).
It's only a 4" trench so I'm going power one side, date the other and separating them with lengths on 2mm galvanised steel sheet on edge down the middle of the trench, so it might not even be 50mm a lot of the time (I'm trying to minimise impact on the garden hence the narrow trench)

DavidY

4,459 posts

285 months

Tuesday 20th September 2016
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Don't forget to switch over to generator you need a isolation switch, to avoid eletrocuting the electrical worker who is working on repairing your line!!

Digitalize

2,850 posts

136 months

Tuesday 20th September 2016
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Going to all that trouble then fitting Cat 5e? Cat 6a is the latest fully accepted standard, with Cat 7 also partially accepted.

Some sort of optical/fibre might not be a bad idea, but the standards aren't in place yet. If you've got the ability to add more via pulls later on I wouldn't worry. Just make the pipes big!

As for other lines such as telephone, you can repurpose Ethernet, it's sort of the beauty of it.

mel

Original Poster:

10,168 posts

276 months

Tuesday 20th September 2016
quotequote all
DavidY said:
Don't forget to switch over to generator you need a isolation switch, to avoid eletrocuting the electrical worker who is working on repairing your line!!
Don't worry, both buildings are coming under building regs so will have to be certified and signed off anyway.

Royce44

394 posts

114 months

Tuesday 20th September 2016
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whats your mains incoming supply rated at?

ATG

20,688 posts

273 months

Tuesday 20th September 2016
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Heretical view perhaps, but I wouldn't bother trying to future-proof data cabling. I'd put what I needed in now and make sure there was a good chance I'd be able to run something new down the duct come the time when it was needed. My hunch is that the future is wireless anyway. If you run 6xcat5, I bet one shiny new 10p coin that you never need more than one of them before they become obsolete.

vetrof

2,489 posts

174 months

Tuesday 20th September 2016
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ATG said:
Heretical view perhaps, but I wouldn't bother trying to future-proof data cabling. I'd put what I needed in now and make sure there was a good chance I'd be able to run something new down the duct come the time when it was needed. My hunch is that the future is wireless anyway. If you run 6xcat5, I bet one shiny new 10p coin that you never need more than one of them before they become obsolete.
Run a bit of string through it.

shtu

3,481 posts

147 months

Tuesday 20th September 2016
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Digitalize said:
Just make the pipes big!
Best future-proofing advice on here.

To me, digging a 4" wide trench and putting metal sheet in is counterproductive. It's as much work as digging a 12" wide one and burying 2x100mm ducts.

(Also, I'd like a photo of that 4" wide trench when you've finished digging it. smile Even with trenching shovels it's near impossible to keep it that narrow.)

Digitalize

2,850 posts

136 months

Tuesday 20th September 2016
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anonymous said:
[redacted]
1 - It doesn't matter what current requirements are, in 10 years time Gigabit Ethernet might be pathetically slow.
2 - See above.
3 - Moving data quicker
4 - Not sure what you mean here
5 - OP mentioned Fibre, it can in theory support massive amounts of data, but I know little about it.
6 - Yeah, it's what I've done in my house, run Ethernet everywhere, even where it's functioning as phone line.

eliot

11,465 posts

255 months

Tuesday 20th September 2016
quotequote all
I've installed lots of ducting around my place. I used the proper corregated 63mm stuff.
I found that the pipe fills up with water and using drawstrings doesn't really work more than once or twice.
So you either need to use fully waterproof pipe, such as large bore water pipe or plastic drain pipe or ensure your cables can be fully imersed and cope with the friction of additional cables being pulled.

THe problem with drawstrings is that the wires get twisted around each other like a chinese finger puzzle. The solution is to use a 'duct or cobra' rod - to pull cables through (which is what the pro's use)

mel

Original Poster:

10,168 posts

276 months

Wednesday 21st September 2016
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Thanks for the pointers, all noted and considered. The main bit of the trench to join up all the "fox holes" is being dug now and since it's a "Ditch Witch" cutting it in the 4" width is apparently pretty consistent and true (I'm at work and haven't seen it yet). I've discarded the idea of any sort of fibre cable and also any additional phone/alarm cables and will stick with the Cat5e, plus coax, I'm also going to put a DMX control cable down there for perhaps some garden lighting that might be fun (I'll put this in the ducting as it's only a screened, low voltage signal wire so shouldn't interfere with the Cat5) Everything all runs back and terminates in my Boiler House/Services Room which will have the Boards, plus switch and router in a 19" cabinet, server, control panels for av, alarms etc. Since there's room in the 19" cabinet this is why I thought about putting in a DMX controller just for giggles of having a disco in the garden really.

Also because I've been too tight to buy 6x boxes of ducting grade cat5e and have bought just a single 1000ft box I'm going to lay all the cables out in the garden first, cut too length then tape it every metre or so to keep it together and pull it as one with three extra drawstrings running free alongside. Hopefully this will reduce the risk of entanglement?

eliot

11,465 posts

255 months

Wednesday 21st September 2016
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I think multiple single use drawstrings should work. I was pulling a new string through with each cable pull - which was a mistake i think.