combined earth + neutral cutout

[rich spark]

hi everyone, hope you can help. im currently installing a small submain to supply a DB which is then supplying a cctv power supply. there is a new lucy 25amp cutout in an external cabinet which has recently been installed prior to my work being carried out, when i have carried out work which involves a lucy cutout there has always been an earth block already fixed onto the side of the neutral block. The one i am working from just has concentric cable to Live and to the CEN block.
So i am asking if i require an earth rod to a new earth block, or bring an earth cable from the neutral block to an earth block? I would put a rod in myself but i just want to be 100% sure.

thanks

 

[Guest55]

your neutral and earth are connected to the same terminal block within a pme cutout.
the smaller 25a lucy units dont have a seperate earth block.

 

[rich spark]

so my 4mm 3core submain would be connected live on the outgoing of fuse, and the neutral and earth inside both on the CEN block?

 

[Guest55]

yep.
done it myself a 1000 times with my stint in the highways electrical sector.

 

[rich spark]

thanks for the reply,its helped. i was ready to buy rods and cable tomorrow .

 

[Engineer54]

What sort of overall installation are you working on?? Some sort of Highways installation??

Generally, If we are talking about a ''Submain'' from a PME/TNC-S supplied main distribution board, then you can't go making further N-E connections as you go. A PME connection is made ONCE at origin, the main distribution board should then be distributing sub-mains as TN-S, where the earth requires a separate earthing block (EMT).

 

[GLENNSPARK]

What sort of overall installation are you working on?? Some sort of Highways installation??

Generally, If we are talking about a ''Submain'' from a PME/TNC-S supplied main distribution board, then you can't go making further N-E connections as you go. A PME connection is made ONCE at origin, the main distribution board should then be distributing sub-mains as TN-S, or TN which will require a TT earth at the load end of the distributed sub-main.

well...i thought it was clear about creating TN-C....

 

[Engineer54]

well...i thought it was clear about creating TN-C....

lol!! i didn't take notice that he has a 3 core sub-main, so corrected my original post!!

 

[GLENNSPARK]

i mean has it been verified that PME is available here?

or is the O/P just goin `off the cuff`?

 

[GLENNSPARK]

sorry...just re-read #1...
been working 14 hours today so...