Any electricians out there? :)

[ben_wooduk 0]

Any electricians on here, I'm after some advice?

I need to run two cables to the bottom of the garden, one for plug sockets and one dedicated line for a hot tub. 

Am I right thinking 6mm SWA for the hot tub and 2.5 SWA for the plugs sockets?

I fully intend on paying an electrician to actually connect them to the consumer unit, I just want to save a bit of cash burying the cables myself (and I'm also a little OTT about my garden). 

Appreciate any advice for a total novice! 

[Cressa 44]

The first question is what load is this supply using. How many kW of power is the hot tub and what load are you wanting to plug into the sockets.

Then what length from the consumer unit to these items.

Then is the cable buried or in free air etc...

All of this will decide on the cable size.

You could get away with taking one swa cable out there as a radial circuit. Going to the hot tub isolator, then to the sockets... All weatherproof I assume unless you have a building up there.

Do you have a spare any in your consumer unit that is RCD protected, or you could fit an RCBO instead of an MCB to give you the best protection.

(Sorry for using electricians terminology) 😇

Ha, wish you hadn't asked

[ben_wooduk 0]

HA HA Cheers mate, i only learned what SWA meant today. 

According to the pre-delivery pack the tub is 16 AMP and i think around 20 metres of cable will be needed. I'll be burying the cable round the edge of the garden about a foot deep. 

Apparently to sign off the delivery and installation of the tub it must be on its own fused spur (i assume that means its own cable?)

Plenty of space in the consumer unit i think, i vaguely remember the electrician who fitted the consumer unit telling me he future proofed it and left some space. 

Most of the the sockets will be under shelter but i'm intending to use weather proof everything to be on the safe side. Load wise, quite heavy i'd say, a pellet grill, outdoor heaters and a TV, maybe all at once :/

Many thanks for your help mate, very much appreciated! I generally don't like getting electric quotes because i haven't got a clue, you could tell me anything! 🤣

[seanl82 23]

It depends how anal your sparky is. I used 10mm swa to a shed at a sub main about 30m from the house. Everything including the swa, sub main consumer & RCDs was bought and run by myself. Its 100a at mains, supplies a 63 MCB at sub main for 6a RCD for lights, 32a sockets & 63a for hot tub. I've got a separate iso switch for the hot tub in the shed, though it's not connected yet as I've only got a 13a tub ATM - future proof. I paid £200 for the sparky to drill through the wall (2.5 ft of stone), install a JB and connect at the main consumer unit (which already had a spare RCD)  then test to get the sign off and certs for building regs. Took him about an hour, but he wasn't fussy in all honesty.

[Cressa 44]

Pellet grill and outdoor heaters... you definitely need to know the power rating of all of these. Sounds like they will draw more current than your hot tub.

Sean's method is the best way by far but does involve more time and cost. If you had a building at the top end of your garden, that would the best way to go. 

But 2 circuits from your existing  consumer unit will do the job👍

The beauty of electrics is there are always many ways to get things working. 

[fla 9]

Separate spur means its got a separate isolating switch inside (one of those fuses with a switch with an orange neon fitted) and perhaps on another circuit breaker at your consumer unit. Whats the current rating of the hot tub? Usually the largest breakers are 32amps in the consumer unit so if you're above say 15 amps its best to use a separate one.

 

The new breakers have smaller low amp RCDs attached - i think the rules have changed recently. Best to check with your sparky.

[ben_wooduk 0]

Cheers for the response all, I can always rely on this forum 🙂

From reading your comments (and cressa's concerns regarding power rating) would i be best biting the bullet and run two bigger 10mm SWA3 core cables to the bottom of the garden, for future proofing?

I have done some reading about RCDs and hot tub isolating switches etc but to be honest, i'm just going to run the cable from the consumer unit (not connected) to the bottom of the garden and let the electrician do all the important stuff, i don't intend to cut a single wire myself as I haven't got a clue what i'm doing.

I'm thinking i could just buy this and be done with it? https://amzn.to/3odoLJd

Edited October 21, 2020 by ben_wooduk

[seanl82 23]

One 10mm cable should be enough depending on how much load and the length you're running, with a sub main at the bottom as it'll be more economical and neater than running 2 X 10mm cables (they're pretty big and expensive). There is a calculator on the TLC website that'll work the cable size out for you if you know the load. Bear in mind that the cable should really be buried (hence the mention of fussy Sparky's). Mine was run behind my fence and supported every 50cm with clips.

[Cressa 44]

3 hours ago, ben_wooduk said:

Cheers for the response all, I can always rely on this forum 🙂

From reading your comments (and cressa's concerns regarding power rating) would i be best biting the bullet and run two bigger 10mm SWA3 core cables to the bottom of the garden, for future proofing?

I have done some reading about RCDs and hot tub isolating switches etc but to be honest, i'm just going to run the cable from the consumer unit (not connected) to the bottom of the garden and let the electrician do all the important stuff, i don't intend to cut a single wire myself as I haven't got a clue what i'm doing.

I'm thinking i could just buy this and be done with it? https://amzn.to/3odoLJd

Mate, 2 x 10mm swa cables is massive overkill, Dont do it. 4mm swa cable would suffice the hot tub. You do need to know  your heater power ratings b4 going any further. Do they just plug in or need to be hard wired via an isolating switch l

[ben_wooduk 0]

Oh no, the TV, patio heater and pellet grill are all on 13amp plugs, i use them on an extension cable from the house at the moment but i'd very much like to stop doing that 🙂

Would running two 6mm SWA cables do the trick then? I really don't mind spending a little more than than i should if it means never having to dig up cables again. 

@seanl82 I'll be burying the cables myself before i get anyone out to complete the electrics. Thats all i want to do to be honest, i'd rather i did the messing in my garden and let the electrician concentrate on the things that could kill me 🤣

[Cressa 44]

How many watts of power is each unit? If you are having a maximum of 13A heater and a 13A pellet grille that plug in, 《26A》you are already on your way to a needing a 32a radial circuit. I doubt they use as much as 13amps between them though as you are using them on an extension that is only protected by the 13A plug top fuse

You will be better asking the electrician what cable he wants , then you do the donkey work. 

2 x 6mm 3core swa are more than adequate and certainly future proof . A smaller cable would be sufficient.

[ben_wooduk 0]

22 minutes ago, Cressa said:

How many watts of power is each unit? If you are having a maximum of 13A heater and a 13A pellet grille that plug in, 《26A》you are already on your way to a needing a 32a radial circuit. I doubt they use as much as 13amps between them though as you are using them on an extension that is only protected by the 13A plug top fuse

You will be better asking the electrician what cable he wants , then you do the donkey work. 

2 x 6mm 3core swa are more than adequate and certainly future proof . A smaller cable would be sufficient.

Thank you so much for all your help mate, really appreciate it!!! I'll get a few different quotes and go from there 👍👍👍👍