Ze(S) DB2

[ste-b]

Hi all, a competant person very conscientious would appreciate advice on Ze(S) test at DB2 outbuilding, I believe not classed as Ze test as not external to db, is this classed as Zs test, as test at main disconector switch with earth still in place.
Have been on threads before & had p taking from electricians, i am aware & understand your knowledge is much greater than mine & hope to learn more from your knowledge,
regards Ste-b

 

[Sintra]

What you are describing is not Ze as that can only be taken at the origin. It is in fact the Zs of the submain feeding DB2. It can also be referred to as Zdb

 

[High Tower]

As sintra says, you are describing a ZDB value. This is a reading of ZS and if substituting a reading of ZE on a certificate for ZDB then it should be taken with all parallel paths in place and recorded, however this should made very clear on the certificate. This is sometime necessary in the event of not being able to isolate the whole installation to measure ZE.