Future proofing cables in a trench

[mel]

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.

[mel]

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)

[mel]

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.

[mel]

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?