Transpositon of eaths.

[scotsparky]

Hi folks i have just tested a saw mill and the earths have be transposed from the main building to the sheds with no rods in place.

Any idea what the reg is which says a rod has to be fitted?

 

[Darkwood]

Without any info we can't reply ....

What is the nature of the supply system?
What size earthing?

come on scotch you know better than to just ask a blank question!

 

[scotsparky]

standard Tn-C-S system
16m main earth 2 supplys to different sheds by way of 4cSWA burried

 

[Engineer54]

Depends what size the 4 core SWA cables are, and if there is any extraneous earthed metalwork within these sheds...

Extending a TNC-S/PME equipotential zone is not in itself against any regulations...

 

[scotsparky]

there big metal sheds 16mm3c SWA long run so possible volt drop but no proved as its an EICR

 

[Darkwood]

What is the size of the incoming supply this will determine the requirements for equip' bonding thus the options you have if your 16mm isn't sufficient.

 

[Chr!s]

Lots of Big metal sheds are PME!


Chris

 

[Darkwood]

Lots of Big metal sheds are PME!


Chris

Explain your comment please.... We are not allowed to create or extend a PME set-up thus im confused by your comment?

 

[Chr!s]

Explain your comment please.... We are not allowed to create or extend a PME set-up thus im confused by your comment?

DNO's will often allow a single supply to be distributed between large metal units, its where there is more than one supply, diverted neutral currents from several supply's may become problematic.

Probably not relevant to the op, just an of the cuff remark.

Chris