Second DB (sub main from first?) Doesn`t HAVE a ruddy Ze. It has a Zs (DB), that is all.
Think about it - the "e" in Ze is "External"?? You couldn`t possibly test Ze at a sub DB, as you cannot remove the main bonds from there - it can only be done at the MET.
There`s another point, actually. The one building, fed from one HED, will usually only have ONE MET; therefore your suggestion that every DB is an installation doesn`t work, as there is no earthing system in place (unless an outbuilding on a TN has been TT`d), so they cannot be seperate installations.
If you DO fill out certs like this, what do you put as the earthing system at a sub-main?
KME
Think about it - the "e" in Ze is "External"?? You couldn`t possibly test Ze at a sub DB, as you cannot remove the main bonds from there - it can only be done at the MET.
There`s another point, actually. The one building, fed from one HED, will usually only have ONE MET; therefore your suggestion that every DB is an installation doesn`t work, as there is no earthing system in place (unless an outbuilding on a TN has been TT`d), so they cannot be seperate installations.
If you DO fill out certs like this, what do you put as the earthing system at a sub-main?
KME