Stevos,
Am a bit concerned about the implications of your last post (if you will excuse the pun). You mention T&E and then ask
The duct you would install is only to provide an easy way for the cable to be pulled in after the groundworks are done. The duct provides NO additional protection for the cable that will be pulled in. The cable TYPE that will need to go in there is Steel Wired Armoured Cable.
The size of the cable will be determined by the designer (your electrician). He will also determine what needs to go at the far end - this is where the type of earth at the origin (and other considerations) come into play.
There is no reason for you to lay a second duct, unless you also want to run other services (ie telephone/data). Because of wiring regs, and the problem of interference, these should not share the same duct as the power cable.
Am a bit concerned about the implications of your last post (if you will excuse the pun). You mention T&E and then ask
I'm still wondering what sort of cable would go through it (in terms of capacity and type), and whether it's worth running two lengths of duct whilst I have the trench dug to future proof it, or whether that would be overkill.
The duct you would install is only to provide an easy way for the cable to be pulled in after the groundworks are done. The duct provides NO additional protection for the cable that will be pulled in. The cable TYPE that will need to go in there is Steel Wired Armoured Cable.
The size of the cable will be determined by the designer (your electrician). He will also determine what needs to go at the far end - this is where the type of earth at the origin (and other considerations) come into play.
There is no reason for you to lay a second duct, unless you also want to run other services (ie telephone/data). Because of wiring regs, and the problem of interference, these should not share the same duct as the power cable.