advice

[domestic spark]

hello, got a job needs a supply outside to a log cabin for a hot tub, two socket outlets and one light.

what i was thinking of doing was running 10mm 3 core armoured.

i was goin to install a ccu next to original with a 30ma rdc. split the tails, henley block.

run the armoured 600mm underground 15m max, and once in the log cabin gland off and put another 3 way consumer unit again with 30mA protection.

then in t&e 1.5 wire a swich and light

in 2.5 t&e put two sockets in.

and off the same board wire in the hot tub.

will 10mm 3 core armoured over 15m be ok?

cheers guys!

havent done much armoured. if you know a better way, step by step it thankyou!

advise much appreciated!!

 

[SMB]

Not looking for trouble mate.

Your question has interested me.

And it appears that no earth stake is required.

Import the PME and all will be fine.

 

[domestic spark]

Generally speaking the exportation of a TN-C-S supply is the decision of the local DNO and only done with their permission. In the absence of such permission it would be recommended to use a TT system and RCD protection. However most DNO's will allow such exportation to an outbuilding provided it is 2 meters or less in distance from the main
building.

I advise that you check with your local DNO as to their requirements."

look what i have found!

 

[domestic spark]

every one has said tncs (pme) but............provided it is 2 meters or less in distance from the main building.

 

[domestic spark]

feel free everyone to add comments? confused.com

 

[SMB]

Get some proof typed down on here then mate.

EARTHING IS SOMETHING THAT LOTS OF PEOPLE STRUGGLE WITH UNDERSTANDING.

im stupid though and I expect there will be clever people replying shortly.

a hot tub room is a special location (same as a swimming pool eerr 701 or 702 something.)

 

[SMB]

I want a copy of GN8.

 

[domestic spark]

whats your opinion please?

 

[SMB]

Get Ken to do it.....

 

[domestic spark]

do what? whos ken?

 

[SMB]

I think Ken lives in London.

good luck mate.

over, and definately, out.

 

[billy110]

Ze is measured at the origin of the installation, I don't think your log cabin is the origin of the installation?

 

[Engineer54]

Your question has interested me.

i thought i knew the answer....i thought TT was the answer.

I was wrong.

Ive contacted a few people about your question, people who i respect. Your question is interesting.

one of the people i contacted was my college tutor.

Everyone ive spoken to so far has said a TT system is good practice in this situation.

I asked for proof to show it on here but there isn't any proof in writing.

Since coming on UK electrical forums, i've been amazed at the tendency to TT everything that involves a sub-main cable to shed or garages and the like, WHY?? ....I honestly can't understand the reasoning behind it!!

It took years to get the majority of the old domestic TT systems converted to PME, by the old leccy boards. Some are still being converted to this day. And here you are creating ''More'' TT systems, ...mostly i fear, because you think it's cheaper than running a suitably sized cable or an additional bonding cable.

The fact is, to create a REAL TT system is far more expensive, but then many don't provide a real TTsystem, mostly you just bung a rod in the ground and think it's a TT system. In the vast majority of cases it Isn't, your relying ''Totally on an RCD device for providing earth fault protection.!!! I also wonder how many electricians know how to maintain a TT system, let alone be able to inform there clients how to maintain them.

Domestically speaking, a TT system should ALWAYS be the LAST choice of earthing system, and considered only when all other avenues have been exhausted. For those that are still under that age old myth that a PME earthing system cannot in any circumstances be extended to an out-building, really do need to understand the Reg's much better than they do now. I believe that even here on the Forum, there is clarification on this issue in one of the Sticky's.

The fact is, ...You CAN take a PME earth with your cable, when supplying domestic outbuildings even when there is water or other services present in that building. There are no rules or Reg's saying you can't either....

 

[SMB]

I think TT and out buildings might be a grey area for alot of domestic electricians?

 

[domestic spark]

Ze is measured at the origin of the installation, I don't think your log cabin is the origin of the installation?

thought so, so thats exceptable?? done 2392 testing course, but that doesnt mean you know everything! so as im no longer at orign, thats an acceptable reading??

 

[Hawk81]

thought so, so thats exceptable?? done 2392 testing course, but that doesnt mean you know everything! so as im no longer at orign, thats an acceptable reading??

yes it is