Help with earthing question....

[bilbo_88]

alright guys

need some help with the following question, struggling a bit;

Consider a TT installation and the earthing arrangements, what do the regulations require in respect of limitation of damage to this arrangement.

Any ideas??

 

[Janjua]

The regs require that an earth rod and RCD be provided to protect the final circuits.

 

[sjm]

Perhaps the answer might be that the connection to the earth rod is mechanically protected from damage and available for inspection. However tapes and plates may be permanently connected by soldering or brazing and this joint will not require inspection. Janjua is also correct that any TT system must be protected by an RCD. Also it is reccommended that the Ze value is below 200 ohms as anything above this may become unstable.

 

[Janjua]

Quite correct about Ze