Ze and PFC

[Bradzz]

Hi all, question im testing an installation that has 1 * 14 way 1* 12 way 1* 2 way 1* 1 way, all of the same incoming phase. 3* meters.
the qeustion is when inputing the Ze and Pfc do i take the highest reading and input this onto each test sheet or do i take a reading from each db and note this down for each db sheet. Say i had a reading from the 14 way Ze of .16 do i note this down on each sheet as they are from the same incoming supply, or do i test each and note down the results for each db on the sheet for that db.
the system is all conduit.
3 phase service head, only 1 phase used, then split at heanley blocks, to 3 * meters., then of to 4 db 1 meter is doubled up, do i code this as this is DNO.

cheers.

 

[dagrat]

The ze is only taken from the origin of the installation, the Eli at each board is put on the inspection sheet as the Zs of the distribution cable and is termed Zdb

 

[rich.250]

Your Ze will be at your main switch for the installation (the origin) and then Zdb should be recorded at each unit.
As for your pfc, pscc and pfc should be recorded at origin and the highest recorded as pfc on the cert.

 

[rich.250]

Too slow..... Lol

 

[Bradzz]

service head 3 phase 4 wire, only 1 phase is in use, so installation is single phase, from service head to 2 hen blocks, split into 3 supplies 1 each for the tarrif meters, do i take 4 seperate Ze readings and pfc/ pscc, or do i take the highest reading and then use on each test sheet.
I hope im making myself clear if not i will try again, im sleepy.
but cheers for your reply's

 

[kingeri]

An installation can only have one Ze.....taken at the origin of the supply! As said, readings taken at the DBs would be Zdb.

 

[rich.250]

service head 3 phase 4 wire, only 1 phase is in use, so installation is single phase, from service head to 2 hen blocks, split into 3 supplies 1 each for the tarrif meters, do i take 4 seperate Ze readings and pfc/ pscc, or do i take the highest reading and then use on each test sheet.
I hope im making myself clear if not i will try again, im sleepy.
but cheers for your reply's

In this situation with no main isolator. I'd be tempted to test form the blocks.
Also do the Zdbs aswell.

 

[dagrat]

Ah, I was thinking sub mains. In answer to your question if all three cu's are at the origin then yes, take Ze at the incoming side of each board and use the highest. In my opinion

 

[Bradzz]

Ah, I was thinking sub mains. In answer to your question if all three cu's are at the origin then yes, take Ze at the incoming side of each board and use the highest. In my opinion

ah a man that can see what im talking about. yes all the db are at the orign, so would this mean as i was thinking take the highest reading.

 

[Bradzz]

Sorry i also should of said the reason i was asking is that the softwear program im using to complete the forms only allows me to input 1 figure in, and allows me to put in additional db circuits, unless im using it wrong, its easycert.

 

[dagrat]

Yes Bradzz, the Ze must be taken from the origin and in this case all three boards are at the origin. so therefore you could take the Ze from the Henley blocks, but I would take the highest reading from the incoming side of each board. The readings will in all probability be substantially the same in any case.
Hope this helps, D