Been having an argument with a friend just lately over consumer units, or
rather the placing fuses, yes I know modern day it's circuit breakers but
principal is the same, within.
I was always told that next to the main switch, you start with the lower
current, lighting circuits (6A) building to the larger Shower/Cooker
circuits (32A) being farthest away. This is so that if the lights went out,
you would be able to find lighting fuse in the dark.
Friends says higher current first next to switch.
Is there a rule for this or is it just personal preference.
On my unit, I have the lowest value next to the switch with the value
getting higher, however there are two empty spaces before the first
'fuse', so if other circuits were added this would no longer be the
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Most electricians start with the highest rated circuits next to the main
switch (or RCD if a split load box).
Ask on the uk.d-i-y newsgroup if your server allows it. I know it has been
mentioned there before.
apologies for blank post (hit wrong button)
In answer to your question the larger raters fuses/breakers should be
positioned nearest to the incomming supply ie the switch/elcb.
The logic behind this is simple volts drop.
the more load you take the greater the volts drop along the conductor (ohms
Even though the busbar is copper it still has a resistance so (in theory at
least) it is better to position the higher loads as close to the incommer as
Having said that most early instalations only have 6 or 10mm tails feeding
the board so volts drop becomes a laugh when ppl have 9kw showers .
No doupt this will stir up a hornets nest of replies but the answer is
straight from the early MEM consumer unit guide.
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