Exporting Tnc-s system

aargeitakis:

Goodmorning all

i have to put power to a wooden shed which is 50 metres away from the house. They will be no services in the shed

I will use SWA cable.

can I export the TNC-S system or I have to make it TT


regards


Paul

TN-C-S should be fine inside  a normal domestic shed.  I do like TT though for outdoor stuff like ponds. I feel it is safer. Use a nice big S.W.A cable to reduce Volt drop, especially if you are going to use machines with motors.


Z.

mapj1:

Well, I could say with TNC-s you are never sure the potential the CPC will be, relative to earth.  ?

 

And if you distributed TN-S with modern cables, you'd be stuck if the separate earth conductor were to break too, it's just there'd be no indication of that until it was too late ? ... at least with TN-C-S you get over and under voltage conditions, that are detected ... a broken neutral in TN-S can be just as damaging.


There are pro's and con's with each earthing arrangement, but I'm convinced that mixing the means of earthing in small curtilage properties, and many other installations such as those dealing with explosive atmospheres, buildings with lightning protection systems, etc, is simply not a good idea.


 

gkenyon

There are pro's and con's with each earthing arrangement, but I'm convinced that mixing the means of earthing in small curtilage properties, and many other installations such as those dealing with explosive atmospheres, buildings with lightning protection systems, etc, is simply not a good idea.


 

And, of course, EV installations! Pity that message wasn’t relayed to City and Guilds for their 2919 course which has the conversion from TNCS to TT front and centre of the assessment.

There are still many charge points that require an earth rod and I am sure end up installed in built-up areas with PME services. 

Tomgunn:

If you're not part of a part 'P' scheme, or going through the local council, then you cannot fix a new CCU in that shed / office so use a switched spur for your connections within the shed / office area.


Also, if you're not part of any scheme, etc, then you are not allowed to run a 'new circuit' either.


It'll be 'interesting' to see what 'comments' / replies this gets!


Just saying...


Tom


 

 "switched spur" with fuse still makes it a circuit Tom..?

ebee:

Tomgunn:

If you're not part of a part 'P' scheme, or going through the local council, then you cannot fix a new CCU in that shed / office so use a switched spur for your connections within the shed / office area.


Also, if you're not part of any scheme, etc, then you are not allowed to run a 'new circuit' either.


It'll be 'interesting' to see what 'comments' / replies this gets!


Just saying...


Tom


 

 "switched spur" with fuse still makes it a circuit Tom..?

Hello Ebee.


I am not saying that by using a 'Switched spur' that you'd be able to run a 'new circuit!'


I'm saying that he, (if he's not a part P member or going via the local council), cannot fit a new CCU, (or run a new circuit),... instead use a 'switched spur' instead of fixing a new CCU.  


I have not mentioned anything about using a 'switched spur' would allow him / anyone, to install a 'new circuit!' 


He'll have to use an existing circuit / other for the supply.


Anyways Ebee... have a nice weekend, I know I need to take some time off BUT, I'm moving house and that's VERY stressful!


Cheers!!