I want to install a secondary consumer unit so that I can do some
outdoor wiring. I'm happy with the technicalities of how to wire from
the consumer unit.
But,can anyone tell me in practical terms how to connect the secondary
unit to the incoming mains and what parts to use.
I thought I would simply be able run some wires from primary CU to the
secondary by inserting some new wires into the same terminals as the
incoming supply on the primary CU but of course 2 wires this size
won't fit into the terminal holes.
Can I fit a terminal box and tap into the incoming wires?
Any help and advice on what parts to use and buy would be greatly
I am assumming I have to 25mm sq cable for the new consumer unit
How much would it cost apporxiamtely to get the electricity board to
come and connect the secondary unit?
On 2 Nov 2003 02:13:34 -0800, firstname.lastname@example.org (Mark)
Yes you can.
You need a service connector block. e.g. MK1100
These are also colloquially known as "Henley blocks" after the most
well known brand.
Needless to say, the power needs to be disconnected. Removing the
fuse at the meter position is the normal way to do this. It was
considered technically to be illegal to remove the fuse seal, but
nowadays, electricity suppliers appear to be relaxed about this as
long as you don't touch the separate meter seals.
You could also consider fitting an isolating switch in front of this
to allow for future work.
You would need to ask them since prices seem to vary a lot.
To email, substitute .nospam with .gl
I couldn't tell from your description whether the secondary CU is going
to be nice and close to the existing CU and the main service fuse. If
it is, the Henley block is the way to go, and the 100A isolating switch
is a Good Thing too. But if the secondary CU is some distance away (more
than a couple of metres), it's both too expensive and not safe to run
gert long 25mmsq tails to it relying only on the service fuse to protect
them. Rather, you'll want to take a sensibly-rated way out of your main
CU (30A, 40A, in the extreme 63A) and feed your physically-remote CU for
the outdoor circuits via a suitable "submain" cable - depending on
max loading, distance, need for mechanical protection and so on, that
could be beefy twin-and-earth (6 or 10mmsq), SWA, or the useful halfway
house of Supertuff.
"Normal" circuit-design calculations will tell you what cable and
overcurrent protection to use.
You need to turn the power off, probably by pulling the lecie borad fuse.
You then use a connector box (screwfix) to make the meter tails (Screwfix) into
a "T" shape, one set to each consumer unit.
You have to be real carefull that you get it right, cause you need the lecie
board round to refit the tag on the fuse.
On 2 Nov 2003 02:13:34 -0800, email@example.com (Mark) wrote:
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