Garden power

[Snowyy]

Hi
Just after a bit of info about garden power, and don’t worry I will not be doing any of the connections myself and will be getting an electrician to do the work as I understand it needs to be notified to relevant organisations (part P).

What I’m looking at doing-at the most we will want to run would be about 20 garden lighting around perimeter (led type 3-5w each), a hot tub-13amp/32amp the ones I’ve seen having a 2/3kw heater, sockets for power tools (jet wash etc) and potentially infrared heater for decking area or summer house.

Am I right thinking I will need a weatherproof consumer unit such as this one (63a rcd) located near where the hot tub or power sockets will be, https://www.toolstation.com/axiom-m...MIjsPav_eO6wIVCu3tCh1XAgIqEAQYASABEgI2u_D_BwE

The main consumer unit is located Upstairs about 20-30mtrs from where I would have the hot tub and I’m aware it needs to be SWA and buried 500mm underground with some caution tape on top of it, used the TLC calculator which suggest 16mm cable from current consumer to new consumer 30mtr away .

The main consumer unit has an unused 63a rcd which was used for a 9.5 shower which had been disconnected and now goes into a Junction box, this MCB has been left tripped off (the white box top left, with the white trunking above it)

as this is a 63a rcd would the electrician wire the swa into this run it in trench to the New 63a consumer where then new circuits can be wired I.e 6a mcb for lighting, 16a mcb for hot tub and sockets. Or is there a better way to do this, only said about the redundant 63a rcd as thought 63a would be overkill for anything interesting the garden even if we opted for the 32a hot tub, which is unlikely, we might not even get a
Hot tub at all but over specifying to future proof.

 

[Taylortwocities]

At the very beginning of your detailed post you said

I will not be doing any of the connections myself and will be getting an electrician

With respect, there is so much that you do not understand, this is clear from your questions.
There are many aspects to this, most of which can only be decided by a detailed survey of your requirements and of the existing installation. this cannot be designed in an Internet forum.
Find yourself a registered electrician now, maybe two. Have them design and quote for the work.

 

[Snowyy]

At the very beginning of your detailed post you said

With respect, there is so much that you do not understand, this is clear from your questions.
There are many aspects to this, most of which can only be decided by a detailed survey of your requirements and of the existing installation. this cannot be designed in an Internet forum.
Find yourself a registered electrician now, maybe two. Have them design and quote for the work.

yeah plan on getting a couple of quotes but I do like to have some knowledge and understanding before hand, I have a very curious mind . I’d also like to do what I can to keep the costs down I.e digging the trench and purchasing, pulling the cable through although i know from past experience that not all tradesman like to do jobs if they cant do it all and charge for the entire job and in fact a few months ago I had a plumber refuse to give me quote/undertake the job of moving the 15mm supplys to a bath as I had already removed the bath, capped the pipes and lifted up floor boards to the pipework and where I wanted it to go, being rude calling me a perfectionist and lazy for not wanting to do it all myself...but that’s a story for another day lol

 

[Taylortwocities]

I’ve never met an electrician who enjoyed digging half metre deep cable trenches!
Most decent trades will be ok with you doing some of the grunt. They are better disposed towards your help if you ask them first. I know it’s your house, but people have their own way of doing things.
Like loading our dishwasher, my way is the only way. But the missus has another (wrong) method. The dishes get clean both ways, but her way is wrong!!

 

[flameport]

The consumer unit linked to is not weatherproof. It's a metal cased cheapo piece of non-compliant unsuitable tat.
Your 'main consumer unit' is a couple of decades overdue for replacement, and is entirely unsuitable for connecting any new circuits to.
16mm² cable would be grossly oversized, and 500mm depth is probably overkill as well.
There is another pile of considerations just for hot tubs, as well as the usual things for everything else.

The absolute minimum would be an enclosure containing suitable device(s) in the house, not connected to the old fusebox in any way
armoured cable from that to a suitable location in the garden
another suitable consumer unit / enclosure there, with circuits for the various items.

The proper option is to replace that old house fusebox completely.

 

[Snowyy]

The consumer unit linked to is not weatherproof. It's a metal cased cheapo piece of non-compliant unsuitable tat.
Your 'main consumer unit' is a couple of decades overdue for replacement, and is entirely unsuitable for connecting any new circuits to.
16mm² cable would be grossly oversized, and 500mm depth is probably overkill as well.
There is another pile of considerations just for hot tubs, as well as the usual things for everything else.

The absolute minimum would be an enclosure containing suitable device(s) in the house, not connected to the old fusebox in any way
armoured cable from that to a suitable location in the garden
another suitable consumer unit / enclosure there, with circuits for the various items.

The proper option is to replace that old house fusebox completely.

Thanks for the reply, yes just wanted an insight really, I had some work done a couple of years ago by an electrician and when he was testing/certifying the work I asked him if the CU needed upgrading and he said it was fine, and when I get someone to quote me for this job if they had said I needed a new CU I would be a bit sceptical. I have a 100ma isolator on the other side of the meter and a 60a CU in the garage as well so assuming there is a Henley block somewhere under the floor boards after the isolator that then splits goes to the garage CU and main house CU. Would imagine an electrician would want to run another feed out of this block to the proposed CU in the garden? or could you fit another Henley block anywhere after it splits but before it goes into the CU as it would be easier to run garden cable from where garage CU is compared to where the block currently would be. Also you said 16mm2 would be oversized, the TLC calc said based on SWA underground for 30mtr and to supply 63A it would need to be 16mm.

 

[Taylortwocities]

I doubt that any Henley block is under the floor - it certainly should not be there!

If it were accessible, then there must be a current limiting device to protect the SWA.
NOTE the 100mA isolator is not an over-current limiting device. Nor is the 60A main switch in the garage CU.

 

[conny]

I’ve never met an electrician who enjoyed digging half metre deep cable trenches!
Most decent trades will be ok with you doing some of the grunt. They are better disposed towards your help if you ask them first. I know it’s your house, but people have their own way of doing things.
Like loading our dishwasher, my way is the only way. But the missus has another (wrong) method. The dishes get clean both ways, but her way is wrong!!

I can so identify with this!