Testing Ze for a new consumer unit in a garage

[skydog]

As Scott and Andy have said.

You'd have trouble measuring Ze at the garage board anyway - after you've disconnected the 'Earthing Conductor' from the MET.

that said,

for a tn-s or tn-c-s earthing system, wouldnt this db2 require its own earth ? i.e. earth rod/spike ?

so by disconecting the earth at the m.e.t. you would stil have an earth reference point at db2 ?

and another question is .....

do you earth both sides of the swa or just the one ? and which side ?

many thasnks jule .

 

[batty]

As Scott and Andy have said.You'd have trouble measuring Ze at the garage board anyway - after you've disconnected the 'Earthing Conductor' from the MET.

that said,

for a tn-s or tn-c-s earthing system, wouldnt this db2 require its own earth ? i.e. earth rod/spike ?

so by disconecting the earth at the m.e.t. you would stil have an earth reference point at db2 ?

and another question is .....

do you earth both sides of the swa or just the one ? and which side ?

many thasnks jule .

I always earth it all the way round the cable find that easiest.



Best to earth it supply end if you are rodneying it in shed or outbuilding.

 

[m4tty]

Lol. What glands are you using mate which only earth one side of swa

 

[Benjo]

Ze is ONLY ever measured at the ORIGIN of the installation (NOT at a remote DB). In my 2391 practical exam, I took Ze at the incomer into the 3 Phase DB and then a Zs measurement at the Incomer of the single phase DB with the main switch of the single phase DB in the OFF position. We were taught to put this measurement down as the ZDB

in the Ze box of the Schedule of Test Results for the remote DB.

Remember, as stated in the regs, Zs can be calculated or Measured!

 

[Andy™]

Ze is ONLY ever measured at the ORIGIN of the installation (NOT at a remote DB). In my 2391 practical exam, I took Ze at the incomer into the 3 Phase DB and then a Zs measurement at the Incomer of the single phase DB with the main switch of the single phase DB in the OFF position. We were taught to put this measurement down as the ZDBin the Ze box of the Schedule of Test Results for the remote DB.

Remember, as stated in the regs, Zs can be calculated or Measured!

a remote DB may well have its own Ze if its classed as its own installation. its 'origin' is the supply to it. which would be a submain from another installation. links to BRB etc stating this area in this thread.

 

[green-hornet]

Very true, you only have the origin at the point of testing, and that is not at the transformer.

 

[Manator]

Very easy to get mixed up with the concept of origin