TP&N Distribution help..

[TPES]

Evening!

I have a dilema

I am looking at installing a 16 way hager 125a TP&N invicta 3 Distribution board.

The 3 phase intake and meter will be on one side of the building. TN-S

I can have the DB as the only DB in the building, running all circuits back to here, some of the furthest RFC's will be using nearly 100m Drums per circuit, then obviously less the closer to the DB I get.

Most circuits T&E

There will be RCBO's mainly through out the board, with a couple of Unprotected single phase ways and 3 phase circuits for lifts..

No do i stay with this set up having 1 DB as mentioned?

Or do Install a sub main?

Or would it be a good idea to keep the 1 DB and mount it in the centre of the bulding keeping circuit lengths shorter, Running an SWA to feed the board from an isolator at the intake?

Or would'nt it matter, all is acceptable ?

 

[pushrod]

Since you've had 8 views and no replies my limited knowledge 2Ps worth is -
I think you need to work out where the main load centres are in the building and put your DB in close to them to minimise run lengths and volt drop problems.

 

[Guest123]

What will the building be used for???

Use would influence my decision on this. Chances are I'd use more than one DB though.

 

[mogga]

as lenny says more info on what usage will be is needed but IMO 2 dbs would probably be better as 100m rfcs would have a right good VD on them

 

[ezzzekiel]

agree with both, add additional sub board and even the load centres

 

[TPES]

Not done a great deal of 3 phase.

looking at these hager boards.. Invicta 3 Distribution Boards from Hager: The New Design and Features « Blog Sparks Direct

at the top theres a 100a top tap off, is this just for the extension to the main DB that sits above it, or is this ok to tap of for a run in SWA across the building to feed a Sub DB?

Im thinking prob not as switching the main incomer isolator will also isolate the Sub DB also

 

[ezzzekiel]

yes it can feed a sub

 

[TPES]

yes it can feed a sub

Would i be right in assuming the main switch would then isolate the sub board also..?

Nothing wrong with this is there? as there is supposed to be one single means of isolation for the whole installation.. would this main switch on the main panel do the job?

Or does it need to be a TP&N Switch fuse between the meter and DB ?

 

[High Tower]

Main switch on Db is fine

 

[Spudnik]

What about protection for the sub main if its taken from the tap off?

 

[TPES]

What about protection for the sub main if its taken from the tap off?

would a BS88 switchfuse isolator be better than the top tap off..?

I've completely mashed my head up on how to configure this install!!

Would appreciate a Instant message chat with someone to clear a few things up if anyones willing?

 

[High Tower]

Sub will prob have to be swa

 

[TPES]

yep going to use SWA, to be honest the submain doesnt have to be 3 phase.

Would i be best to run a 16mm SWA from a 63A MCB to an extension panel.

From one of these http://www.sparksdirect.co.uk/images/lights/JK1125.jpg

To this for Submain http://www.knxshop.co.uk/catalog/imagebank%5Csmall/HAGJK116EG.jpg

Im not sure how these extension panels are set up.. Can i get an isolator on the din rail or will it have to be an isolator outside of the panel?