Thread: MCB ordering
View Single Post
  #3   Report Post  
Posted to uk.d-i-y
ARWadsworth
 
Posts: n/a
Default MCB ordering


"Christian McArdle" wrote in message
.. .
I know it is best practice to shove the higher rated MCBs/RCBOs up towards
the supply side of the bus bar.

However, for new 32A circuits, do people generally re-jig the ordering to
maintain this, or just bung a new one on the end after all the 6A ones?
There would be about 6 to move and it would complicate the existing
wiring,
as there is not much slack.

I presume that DIN rail bus bar is perfectly capable of maintaining the
full
100A right to the end (it's a 16 way type), and the circuit is unlikely to
be loaded to any extent, so I'm not worried about the tiny potential for
any
significant voltage drop. I'm just worried that the inspector will have
some
potential set of personal Hitlerite rules that aren't in the regs and I
don't particularly want to argue the toss.

So, do I bother rejigging the low rating MCBs?

Christian.


I would not bother rejigging the MCBs unless you expect to use a high load.
My downstairs lighting draws more current than the ring main that feeds the
bedrooms but I still have the 32 amp MCB before the 6 amp one. It would
probably be more effective the other way around.

The only thing an inspector in Hitler mode may pick up on is that the
neutrals are not in the correct place in the bus bar. ie MCB 1 should have
its neutrals in screw terminal 1 on the neutral bus bar etc. or be tagged
with labels to show their position.

Adam