I would appreciate your input lads

[wade88]

Alright lads,

Can anyone see a problem with this. Excuse the drawing, im fairly rubbish at clearly drawing things and have most definitely to all you technical chaps out there, murdered the drawing to bits, but im just trying to get scope around the general idea. Which i think is clear enough.

4 core SWA will be travelling across two warehouses to be terminated into new TP+N board. Planning on taking the existing incoming supply and splitting it down via service blocks to be able to accommodate the existing boards (of minimal load) and the new board. Industrial work such as this is not my usual forte, however it is becoming more of what i do now, i feel competent to do the work, would just appreciate a nudge in the right direction should i need it.

Tin hat is on, if you need to be brutal here, by all means go ahead. i want a safe and future proof install so if i need a good kicking to achieve that then im ready for it. I'll do my very best to answer your questions as accurately as possible.

Cheers guys,

 

[Spoon]

Soz Wad, I take it that DB1 & DB2 existing and you are adding DB3?
Is it the schematic diagram you would like commends on or the install method?

 

[Darkwood]

You would require an isolator upstream (supply end)of the swa to DB3 also i assume you missed the N out on DB2 by accident

 

[wade88]

Yes missed the neutral by accident, also forgot to add isolator for DB3, both are present. What i was concerned about really, was just the splitting of the power at service blocks, and phase balancing really.

 

[JD6400]

I think you have not got any form of discrimination in there for the new sub supply ?

 

[Darkwood]

Ideally if designed from scratch the service blocks would be replaced by a busbar chamber with an isolator for each out going supply i cant comment regarding loading as you supplied no info regarding existing loading per phase and proposed new DB3 loading.... using the service blocks is ok as long as the service blocks are not been pushed past their design in no' of cables tapped off or loading of the system overating the blocks, but if possible a busbar would allow for expansion while affording a proffesional look.

 

[wade88]

Well i am putting the service blocks into an enclosure to keep it looking tidy and primarily had considered the bus bar option, but just went for the blocks to keep costs a little lower.

I know guys sorry i havent gone to the lengths so far to provide with more details, my query initially was just in the basic lay out and design. I was just wondering if any immediate alarm bells would ring. The load on DB3 is going to be substantial and will be the primary consumer. DB1 feeds the high bay lighting, DB2 the office above, which is only occupied by two people (minimal draw - usual suspects, 2 pc's, copier, couple of fluros).

Im working late tonight to make a start on the getting the cable basket up not looking forward to it at all.

 

[44ALLAN]

Don't know about anyone else but I always buy SWA with an extra core for a dedicated earth.
Agree with the busbar section too...........far neater IMO.

 

[drew35]

Is that a separate neutral isolator after the meter or a service block? Shouldn't there be a four pole isolator, and not a three for the line conductors only.

(Sorry to hate on the drawing, I use a pritt stick for circles and a 9v battery for rectangles when I do my drawings. They must be sitting on my office desk for a reason?)

 

[Darkwood]

I would spec up the load characteristics of DB1 as you seem to have high bay lighting on 1ph if i read correctly .... you would be supprised at just how much load this may take and its possible you have a heavy loaded phase that will create all sorts of issues if your adding a heavy loaded 3ph board as well.... worse case would be a need to balance the high bay lighting over three phases to give the capacity you may need, also look into heating loads which may not be apparent at the moment while they are off.

 

[telectrix]

if DB1 and DB2 are adjacent, could you not replace both with a 3phase board (with sigle phase outputs) so as to balance the phases better? oh, and the isolator from the meter should be 4 pole IMO.

 

[Knobhead]

Ben, take on board what’s been said about fused switches and the loading for the lighting board. Come back with a new proposal including the length and loading of the separate runs.

 

[wade88]

Thanks lads,

you are all gems

 

[wade88]

Can someone point me in the direction of a 100amp 4 pole isolator that isnt a rotary then. having trouble digging one up

 

[Spoon]

If you are doing to re-draw the schematic I would put location boxes round the equipment (usually done as dotted or phantom lines). I take it that the existing incoming supply and DB's are in one warehouse (unit 11)? I'd also ident the cable going to DB3, as you mentioned, this is going through 2 warehouses before getting to the new DB.

 

[Bobster]

Is it to fit in a db? Or a stand alone unit?

 

[wade88]

View attachment unit 11 boards.pdf
Make more sense?

 

[wade88]

Excuse the rough drawing again, just for illustrative purposes. N currently runs to a service block, and N's taken from it. A 4 pole isolator would definitely be best for this arrangement then and then taken from isolator to seperate block to be split?

 

[Bobster]

So your looking for something similar to the mem switch fitted for db2?

I' recommend the ones we use on site but I think it might be a bit overkill for the purpose your wanting it for?

something like this? http://srselectrical.co.uk/index.php?route=product/product&product_id=567

 

[Bobster]

Sorry realise the link I've just posted is only 3pole.

This is the company we use for isolators, I'm guessing it'll probably be out of your price range

http://www.craigandderricott.co.uk/