Creating high integrity ways in stacked cu

[Bellendian]

Hi, just wondering if my plan is any good or if you've got a better way!

I've got 2 10mm SWA sub mains going to outbuildings, currently fed from rcd protected ways on a stacked Hager CU.

New boards in outbuildings all Rcbo units, so don't need or want RCD protection at house end.

Main switch is on the upper tier, breakers feeding sub mains currently on lower tier fed from 2nd rcd.

Ideally I want to create 2 high integrity ways on the lower tier prior to the 2nd rcd. Breakers would remain in more or less the same place that way.

I've got enough hager bits to clip another neutral bar to the 'bar holder bit' at the top, got plenty of busbar, plus bits of a split load kit.

My plan is to add neutral bar, split bus bar, and use cable from split load kit to take a feed from rcd2 input straight into bottom of first mcb, then busbar to link to 2nd mcb.

So electrically identical to high integrity ways adjacent to main switch.
I'm just a bit worried that it might not be immediately obvious that they are separate from rcd feeds visually if you know what I mean?

 

[telectrix]

might it not be better to split the tails and fit a mini CU with main switch and 2 MCBs to feed the subs.?

 

[HandySparks]

...Ideally I want to create 2 high integrity ways on the lower tier prior to the 2nd rcd. Breakers would remain in more or less the same place that way.

Sounds OK to me provided that everything's clearly labeled. Maybe add a label 'Not RCD protected' above/below the two MCBs.

 

[Bellendian]

Thanks but space is limited, I don't think I'll be able to squeeze in Henleys plus an additional CU...worst case I move high integrity ways to upper tier, to which submains won't reach unless extended, and top tier currently full and a mess ...I'd really like to avoid having to move any of that about!

 

[Wilko]

Given that I like the non protected ways next to isolator, I'd have a close look at the 10mm swa and see of they've kindly left enough slack to pull another foot up and reterminate

 

[Bellendian]

Cheers, already tried that one! They're concreted in and not likely to go anywhere...annoyingly there is excess at the other end where I don't need it!
My latest plan is to move the main switch down to the lower tier, keeping new unprotected ways in the usual place between main switch and RCD. I can't see why this wouldn't work but it's going to be a bit more grief having to mess with tails.

 

[westward10]

I would never reconfigure a board unless that was the nature of the design.

 

[Wilko]

The next thought is to terminate the swa into a metal box and extend up to the correct spot, minimising board rearrangements .

 

[Bellendian]

I hear what you're saying. I am going to call Hager technical before I go ahead, but as far as I can see in this case it is within the nature of the design of these flexible bus bar split loaders.

 

[Bellendian]

Wilko, I think that might be the simplest...I have a feeling I've got space to do that....cheers!