UK Advice on Log Cabin Electrical Plan

[CrimsonEth]

Hi Folks,

I am in the process of building a log cabin in the garden and I am in need of some advice when it comes to the electricity supply. I have formulated the plan below which is the result of much research, so please be kind Needless to say I am not an electrician so once the work is complete, I will get someone qualified to wire the CU's and test/certify the installation.

The plan is to run a single 7 meter 3 core 6mm SWA cable from a IP66 junction box mounted on the exterior of the house (connected to a 32a MCB in the house CU on the opposite side of the wall) to another IP66 junction box mounted on the exterior of the cabin just above floor level. The SWA cable will be directly buried in the ground at roughly a spade depth and will ultimately have a patio on top of it.

In the cabin, I will install a small 'garage' CU mounted just above floor level (aligning with the junction box on the exterior) populated with a 32a MCB and a 6a MCB. The 32a MCB will power 10 sockets on a ring circuit using 2.5mm T&E clipped to the side of the floor joists. Total length of the ring will be roughly 17 meters. The sockets will be used to power an electric oil radiator, TV, sound system, and possibly a kettle. The 6a MCB will power 5 LED lights on a radial circuit using 1.5mm T&E hidden inside trunking. The length of cable will be roughly 10 meters.

Now, the million dollar question... does anything in my plan break UK regulation?
Secondly, should I fit the cabin CU with an RCD or can I use the RCD from the house CU?
Thirdly, am I OK to mount the cabin CU roughly 30cm from the floor?

Thanks in advance.

 

[radiohead]

You don't want a 32a mcb feeding the distribution circuit AND a 32a mcb serving a final circuit. Best practice would be to used a fused isolator (at say 40a) to supply the SWA and have RCD/mcb protection at the shed end.
You should involve an electrician now and verify that he/she/gender neutral - is prepared to certify and notify to BC, and discuss how the installation is to proceed. I....and most others would NOT be prepared to put our signature to an installation that has just been presented finished without any design input and verification that cables are installed correctly, such as depth for the SWA. And most certification schemes do not permit their members to certify 3rd party work, the NICEIC for example forbids it

 

[pc1966]

It seems that radiohead has already covered the key points, and most critically that you really must get someone who is professionally competent to sign off involved from the start. If the tables were turned and you were being asked to sign off that somebody else's work was safe, what you you expect the procedure to be?

In principle what you suggest sounds reasonable, but already covered is you a much better to have fused switch feeding it, have the local RCD (or use RCBOs), and probably to drop the sockets MCB to 20A to get a good chance of selectivity - that a fault is contained to the circuit where they occurred. Again, any good sparky will look at what you plan on using and check these sort of details out.

The only odd thing is why do you want to CU at 30cm height? If it is about aesthetics you can have it enclosed to match the planned interior.
[automerge]1592339705[/automerge]

You should involve an electrician now and verify that he/she/gender neutral

I find they covers all genders, orientations, and species.

 

[radiohead]

I find they covers all genders, orientations, and species.

I very much doubt any term could be used these days without offending someone.

 

[pc1966]

I very much doubt any term could be used these days without offending someone.

Yes, that is true

 

[Spoon]

As @pc1966 has already mentioned, why do you want the garage CU "mounted just above floor level"?
This is against building regs.

 

[CrimsonEth]

Thanks everyone for your replies. Glad to know my plan is mostly solid! I will get an electrician involved now before anymore plans are made.
As for mounting the cabin CU low down, this is purely for appearance. But if this is against regs (thanks @Spoon for pointing this out) I will run the SWA an extra few meters and have it enter a the back of the cabin with the CU mounted at the correct height.

 

[Zerax]

I very much doubt any term could be used these days without offending someone.

I find the non-gender version of "he" or "she" is tricky... as "it" often causes offence.

 

[Lister1987]

I find the non-gender version of "he" or "she" is tricky... as "it" often causes offence.

I i think "they" prefer the "we" pronoun as it addresses both thier male and female commutations and still keeps them neutral. Effectively addressing them in the third person.

Back on track....

 

[CrimsonEth]

I i think "they" prefer the "we" pronoun as it addresses both thier male and female commutations and still keeps them neutral. Effectively addressing them in the third person.

Back on track....

Now I know how to wire the cabin and how to address the electrician without causing offence