Supply to metal shed.

[oneofthedamned]

I have been asked by a friend if I could put a socket and a light in their new shed. I thought this would be a nice little job for whichever scam provider I choose to go with to assess. Upon arrival I find its a metal shed. It stands on a concrete pad so would be a nightmare to TT it. What would be the best way to tackle this type of building with regards earth bonding? It is only 3m from the house and about 17m from the consumer unit.

 

[Apache]

Why not drill through the concrete and whack a rod in - there was a pic on here recently

 

[Apache]

http://www.flickr.com/photos/n-e-electrical/3305130442/

in this thread

http://www.talk.electricianforum.co.uk/showthread.php?t=3200

 

[Andy™]

Whats the supply type in the house? if its TNCS, then i would TT it. if its TNS or TT, you can export the earth to the shed. bond shed. for attaching bond to shed, you could use radiator clamps if there is anywhere to put them

 

[a1]

Nothing wrong with pre-drilling the concrete and banging a rod in.

Nothing wrong with doing it twice to lower the Ra (Zs).

Regards,

Ad.

 

[a1]

Why wouldn't you export a TNC-S, then Andy? :|

 

[Andy™]

Why wouldn't you export a TNC-S, then Andy? :|

If there is a large fault current flowing to neutral, the 'earth' voltage can be higher than ground, so because of voltage difference, you could get a shock.

If the also, if the neutral fails, all metalwork will rise to 230V. now inside your house, all pipework will be the same, so in theory, no shock. but with his metallic shed there, a nice 230V difference between that and what your standing on. with TT and TNS, shed will always remain at or around 0V (Or upto 50V touch voltage)

 

[oneofthedamned]

Thanks for all the advice lads. The supply is TNCS so it looks like TT is the way forward. Next question how many points did I ought to attach bonding to. The panels are galvanised and coated which will make good contact awkward and I don't want little pigtails of earth cable all over the shed or it will look like I've decorated it for xmas. The other problem I can think of are the sliding doors, this job could be a nightmare. :|

 

[Apache]

Thanks for all the advice lads. The supply is TNCS so it looks like TT is the way forward. Next question how many points did I ought to attach bonding to. The panels are galvanised and coated which will make good contact awkward and I don't want little pigtails of earth cable all over the shed or it will look like I've decorated it for xmas. The other problem I can think of are the sliding doors, this job could be a nightmare. :|

As you know I'm no sparky but why not wander around with your continuity meter and see how 'continuous' the metal in the shed is. Are the runners on the sliding door metal? They may conduct OK?

 

[Gforce]

I would suggest just removing paint in an area then attaching earth there-then establish contnuity with all other metal surfaces like the door and supp bond any which arent touching frame of shed-shouldnt be that bad/

 

[steptoe]

If there is a large fault current flowing to neutral, the 'earth' voltage can be higher than ground, so because of voltage difference, you could get a shock.If the also, if the neutral fails, all metalwork will rise to 230V. now inside your house, all pipework will be the same, so in theory, no shock. but with his metallic shed there, a nice 230V difference between that and what your standing on. with TT and TNS, shed will always remain at or around 0V (Or upto 50V touch voltage)

some people do read some of the threads Admin, and some even just use their own common sense.

remember that if you do use more than one rod you leave enough space between them.

BTW andyc, very elequontley put, Applaud Smiley

 

[a1]

I was chain pulling Mr Steptoe, Sir. After all; There is a very famous thread on here on the subject.

But Yes, I do agree that AndyC's reply was well put and I am goign to scoob him for it and e gets a "Thanks".

 

[ABC Technical]

Nooooooooooooooooooo Not the exported earth thread.

 

[Apache]

Nooooooooooooooooooo Not the exported earth thread.

threads..............

 

[SPECIAL LOCATION]

personally....

I'd get a wooden shed...

cuz I luuuuuuuuv the smell of creosote! :x :x:xBlushingBlushing

stuff the lectrics!

give me the creosote!!!!!!!!!!!!!!!!!!!]B-)

 

[SPECIAL LOCATION]

Nooooooooooooooooooo Not the exported earth thread.

SHHHHHHHHHHHHHHHHHHHHHHHHHH!!

don't mention the war! ; \ :^O

 

[Apache]

personally....I'd get a wooden shed...

cuz I luuuuuuuuv the smell of creosote! :x :x:xBlushingBlushing

stuff the lectrics!

give me the creosote!!!!!!!!!!!!!!!!!!!]B-)

it's hard to get hold of now is proper creosote. The substitutes are crap!

I got a friendly farmer to get me a 25L drum

 

[ABC Technical]

Lol, good one specs.

 

[Apache]

They are a right ****** in terms of condensation too

 

[SPECIAL LOCATION]

They are a right ****** in terms of condensation too

what are? ?:|

friendly farmers?