ᐅ Laying underground electrical cables for garden power supply

Created on: 3 Mar 2013 16:59
V
VanTide
V
VanTide
3 Mar 2013 16:59
Hello electricians,

I want to lay two underground cables with residual current devices (RCDs) / circuit breakers to the garden: one for sockets (3x2.5 mm² (3x2.5 sq mm)) and one for lighting (3x1.5 mm² (3x1.5 sq mm)). The garden starts after about 15 meters (15 m (50 ft)) of cable, so the cable length has already been checked.

My questions are about how I should lay the cables:

a) Can both cables be laid next to each other according to the relevant standards (e.g., two trenches in depth, sand, tape, etc.), or do two power cables cause interference?

b) For the lighting cable, there are three lamps, but the cable has only one end. How do I connect the lamps to the cable when they are each about 3 meters (3 m (10 ft)) apart? Do I need to use an outdoor junction box or something similar at the cable end?

c) Do the cables need to be buried deeper or require additional grounding?

d) How can I set it up so that I can activate the outdoor lighting from the living room without having to go to the distribution board to switch the circuit breaker on and off?

Thank you in advance for your help.
V
VanTide
3 Mar 2013 17:01
C means: do I have to connect the cables to a grounding electrode in the utility room, or is there another solution?
J
jbo
3 Mar 2013 20:37
Hello,
are you sure you want to do something like this yourself?
To me, it sounds like you might be cutting corners in the wrong place and possibly putting other people’s lives as well as your own at risk.

Still, here is my brief opinion without any guarantee:
Regarding A: It should be no problem as long as you don’t run a data cable next to high-voltage cables.
Regarding B: A junction box sounds good.
Regarding C: Oh man, get an electrician. Normally, there is an equipotential bonding bar in the distribution board of your house.
Regarding D: I can’t really help you with that now; there are also options using wireless technology.

And again, have a qualified electrical professional do the work.
V
VanTide
4 Mar 2013 21:44
Is there a junction box designed for underground use? Specifically, a waterproof one? How does it work?

The meter box is connected to a foundation earth electrode; is that sufficient? As mentioned, the cable enters the box there.
V
VanTide
9 Mar 2013 18:32
Does anyone have an answer for me? Thank you.