Zdb

mattscaddon · Jun 2, 2013

Hi all,

Please could someone explain this to me.

Scenario Primary Board--Db1-- Db2--Db3. (This is all hypothetical)

I have only just recently left the army, and have taken Electrical study's as my resettlement course and have achieved my 17th ED,2391, EAL Domestic, 2377, but realize i have a long way to go before i can call myself an Electrician. So please go easy on me.

I have taken a ZE reading at the Primary board, and taken Zdb at the remaining Dist boards, suppose i get a reading of 0.23 at Db2,i have been told that this is my Zs for Db3, and not Db2

So when im filling out Db3s schedule of test results,i should enter 0.23 for the Zs value in the box that's headed "to be completed if DB is not connected directly to the origin of the installation".

Thanks

Matt

telectrix · Jun 2, 2013

thew Zsvalue for a DB is the reading obtained at the incomer of that DB. commonly referred to as Zdb2 etc.

mattscaddon · Jun 2, 2013

Thanks Telectrix, i understand that, so i would of thought that the reading i obtained 0.23 would be entered on the schedule for Db2 and not Db3 as i am being told.

telectrix · Jun 2, 2013

correct, IMO.

mattscaddon · Jun 2, 2013

Thanks a lot, So just to sum up Db2 Zs as if i was doing a Ze test but with all Earthing still connected as the installation is still energized,and the figure i measure, in this case 0,23 would be entered as the Zs on Db2 schedule . Ps i think i should of stayed in the army LOL

guest119 · Jun 2, 2013

The primary board db1 will have its own schedule of test results.
The feed to db2 will come from a breaker in db1.
The feed to db3 will come from a breaker in db1.
The schedule of test results for db1 will show a circuit going to db2 and a recorded zs from the end of it.
This zs will also show on the schedule of test results for db2 but will take the form of ze on that sheet.
Ditto db3.

mattscaddon · Jun 2, 2013

Confused.com

mattscaddon · Jun 2, 2013

So my original 0.23 taken at the incomer of Db2 where do i input this figure on the schedules Db2 or Db3, apologies for my stupidity but im not got this yet.