Earthing Systems

[MalcF]

Hi - can anyone tell me how to find out what type of earthing system a property has eg. TN-C or TN-C-S or TT. Should this be displayed at the consumer unit or is there a way of telling by looking at the earth bonding arrangement?
Any info would be greatly appreciated!!!
Regards
Malc F.

 

[JohnD]

Look at the first thread on //www.diynot.com/forums/viewforum.php?f=8

//wiki.diynot.com/electrics:earthing_supply_types_and_bonding:earthing_arrangements

 

[ricicle]

You will only have TN-S, TNC-S or TT.

With a TT system the DNO do not provide the earth - you have to with the use of an Earth Rod.

TN-S usually utilises the sheath of the incoming supply cable and you can see this as the earth exits from the sheath of the cable before the cut-out although it can be taken from the cable inside the cut-out, with a block on the outside.

TNC-S should normally be labelled somewhere near as PME, although don't take this for granted.The earth block is on the side of the cut-out.

There are various horrible versions of these in existence which were ok in their day(eg using the incoming water main).The only sure way of knowing is to contact your DNO

 

[MalcF]

Many thanks JohnD & Ricicle for your replies - thread with diagrams very helpful & info regarding earth blocks good to remember, should be able to suss it out now!!, thanks once again.
Regards
Malc F.