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Alterations to Existing Garden Electrics

Postby Redw28 » Thu Jun 20, 2019 3:34 pm


I already have electrics in my garden but i want to alter them and want to check what I am doing is ok.

Here is a diagram of what is there currently:
Garden Electrics plan.png

Here is the RCD:

The main cable from the RCD is armoured but I am not sure what type it is. The lighting wiring from the 12v transformer seems like normal cable and has been eaten and therefore none of the lights work.

My questions are:
- I want to add new sockets at points H and I on the digram. Presumably I am ok just to cut the cable and add them?
- The lighting cable was previously not good enough so is there an armoured equivalent I should use?
- Do I have any regulatory issues? My assumption was no as the circuit already existed.

I should just add what I want to use the sockets for. The ones at point B are rarely used but could have an electric patio heater, power tools if I am working outside or maybe a speaker. At point G I have only really plugged an extension lead in to get to other parts of the garden. For example I had a cement mixer plugged in when I built the new patio at the back of the garden.
The new sockets at H and I would be similar - Patio heater, speaker, phone chargers.

Hopefully that is enough information. Thanks for helping!

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Simply Build It

Postby Mr White » Thu Jun 20, 2019 5:39 pm

You can not "just to cut the cable and add them" as you have already pointed out, it is a steel wire armoured cable, to add to a SWA cable it will need to be replaced and re-terminated, something that you must get right first time, best left to an electrician.

I should also clarify, its not the whole cable that will need to be replaced, just the cable from the first new socket to the original socket.

There is no problem with you replacing the cable to the 12v lights. You may want to run the cable in PVC conduit if possible.
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Postby Redw28 » Thu Jun 20, 2019 5:53 pm

Thanks for the reply. I can handle the cutting of the cable and installing the new sockets as I have done that elsewhere.

Are you saying it needs to be replaced to provide an amount of extra length of cable so there is ample to get to the new socket?

If so, I should have added that in the top corner of the garden where I want to adfd the new sockets, there is plenty of excess cable as the original electrician laid it straight from the first socket to the junction at point C and from the socket at point G allowing all the excess length between those points to be coiled and hidden behind the old shed that was there previously. So I have too much cable between point C and point E so I can easily insert my new sockets.
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Postby ericmark » Tue Jun 25, 2019 11:32 am

Two basic ways to branch from SWA cable, one is a cable gland and a junction box of some type, the other is a cable joint, the latter comes as two basic types, shrink sleeve with epoxy resin inside it, and filled with an epoxy resin.

The joints are expensive, and although are handy when a digger hits a cable, not really cost effective for a garden.

So you need a gland there are many types, but you need an outdoor type where a stuffing gland part grips outside of cable as well as the bit which grips the SWA and second stuffing gland for inner cores, I have made off so many now second nature, but for a beginner can be rather daunting.

Where glands are terminated needs to be reasonably dry, as from gland onwards hard to make junction box water proof unless you fill it with some compound.
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