Db Off Bussbar

[moose man]

Just wondering

At work i have installed a new 3 phase  distribution board 125A  sub mains 35mm 4core  feed is from a tap off box . 

on a 250A bussbar  i know you take ze at origin    but origin for this supply is  the bussbar so would it be there or supply db for bussbar  then new db classed as Zdb   gone a bit of a blank 

 thanks moose man 

 

[Pete10001]

How far away is your db from the busbar?

 

[Andy™]

well unless your treating the submain & DB as its own installation separate from the rest of the wiring, then you origin is still the same as before you done any work

 

[kerching]

There is only ONE origin......well at least there was when I started.

Probably all done on iPads and Lapdancers now

 

[moose man]

DB IS around 18mtrs from buss bar

I understand  on origin so on test sheet for new db would be classed as zdb as db is supplied from bussbar

 

[Andy™]

have a look at definition of 'origin of supply'

 

[ProDave]

Isn't the "origin of supply" your nearest power station? :coat

 

[moose man]

like I said I understand the origin main incomer to the building from sub station but on test sheets ze will become zdb has its a sub board from the main incomer sub board then

 

[NozSpark]

What the hell are you going on about

Ze is taken at the origin. ... there is only one origin

Zdb is taken at the db.... of which there can be many

 

[Andy™]

Ze is external to installation. i.e external means OUTSIDE the installation. so you will only ever have 1 Ze per installation.

but what the hell, just put what you want, so far you have ignored every reply in this thread and say you know it anyway, so why even ask in the first place?

 

[moose man]

Thanks noz spark at last some one gave me a answer to original question and yes I have multiple boards around the factory

 just wanted to know what to put on test sheet before I start connecting circuits to new db

 

[Andy™]

Thanks noz spark at last some one gave me a answer to original question

so you didnt read post 3&4 by me and kerch then?

 

[moose man]

Andy all I was asking were it says ze on schedule of test sheet 

NOW BECOMES ZDB AND I WAS NOT IGNORING POSTS JUST ASKING A SIMPLE QUESTION ABOUT ZDB

OR ZS AT NEW DISTRBUITION  AND AS FOR KNOWING IT WAS ON MEANING OF ORIGIN

 

[kerching]

Ze

Z......impedance

e.......EXTERNAL

NOT the internally bit nearest to your board before it gets to the externally bit

Everything after a Ze is a Zs.............Zdb. Is Zs at the DB.........isnt Zdb a madey uppy bit?

 

[moose man]

thanks kerch  

much appreciated so wont be putting zdb only zs for db  on schedule of test results

thanks again a sorry for confusion on what was asking's  

 

[Phoenix]

I think you are perhaps confused about how to represent the arrangement on an EIC.

As you have no doubt understood from the other replies, the Ze and PFC etc in characteristics of supply on page 2 refer to the origin of the installation where-ever that be.

Now page 4 and 5 are DB schedules, now you have installed a submain from a tap off unit, so fill this in as is the tap of unit were a DB with one circuit / switchfuse etc. Zdb and pfc taken at the tap off unit (or at the far end of the busbar if you prefer), zs for this circuit will therefore be the measurement at the new board (end of the new submain). Now you'll have to start a continuation sheet to refer to the final circuits fed from your new DB, obviously Zdb and pfc on this one refer to the measurements at new DB

 

[steptoe]

OK,

for my little bit, and its not worth much,

there is NO such thing as a tap off unit,!

unless you are

A . a plumber that uses taps

B . someone that has no idea what they are actually doing

C . see B then A above

 

[Jono Pashley]

OK,

for my little bit, and its not worth much,

there is NO such thing as a tap off unit,!

unless you are

A . a plumber that uses taps

B . someone that has no idea what they are actually doing

C . see B then A above

You might wanna talk to Schneider electric about that then steps since they use that terminology in their canalis range

 

[Doc Hudson]

"Tap off units", examples of the terminology usage within the electrical industry:

http://w3.siemens.co.uk/buildingtechnologies/uk/en/low-voltage/busbar-trunking/Documents/BD2-lv70-2009.pdf

http://www.legrand.co.uk/downloads/Legrand_Electrak_trade_price_list_UK_2014.pdf

http://www.denmans.co.uk/downloads_public/Britmac_Powertrack.pdf

Whether any of these are what the previous comments refer to is another matter though.

Doc H.

 

[steptoe]

Well I never,,,,,

Never heard that term before. :|