On 09/05/2012 20:47, Andy Champ wrote:
On 09/05/2012 15:13, Stormin Mormon wrote:
wrote in message
...
Hi
I hope that someone can advise me. We've just pulled out a kitchen
which was 29 years old and having had a few electricians come in are
really none the wiser! We need to move some sockets around, move the
point for the oven and change the lighting system from a normal light
fitting to LED spots.
The issues that we have are some of the plugs are on old black rubber
system which we know needs to be changed and the lighting system is
unearthed.
The rubber will be well past it (it seems unlikely it was new at the
last rewire if that were only 30 years ago)
The lighting circuit will certainly need redoing (either the whole
circuit for that floor if its shared with the kitchen, or a new circuit
run for just the kitchen). Since there is no compliant way of extending
of changing it now - especially if you want metal fittings or switch gear.
http://wiki.diyfaq.org.uk/index.php?...thout_an_Earth
Some of the electricians are telling us that we can pick up the old oven
power supply and run new cables to the new position using the old cable
which is almost 30 years old but not on the black rubber ring. Others
are telling us that we should tie off and make everything good and run
afresh from the board.
If the cable was installed 30 years ago and is a modern style PVC cable,
there there is a resonable chance its in a usable condition. However the
cost of cable is cheap compared to the effort of wiring. So if its going
to be simpler to replace it then go with that.
It would also need to be adequate for your proposed use. Typically a
modern cooker circuit is wired with 6mm^2 T&E cable, from a 32A MCB.
That is usually adequate for domestic cookers of a total maximum power
rating of around 60kW (there is a generous allowance for diversity with
cookers).
http://wiki.diyfaq.org.uk/index.php?title=Diversity
Note that many single ovens are actually designed these days to run from
a normal 13A socket. Depending on the appliance list for the kitchen
that can be better provided on the dedicated cooker circuit though.
Additionally, on the board only half of the trips are covered with the
RCD. We have been advised that this is fine as is, but others have said
that we need to replace the board entirely and others we should add
individual RCBO trips to each section.
There are several ways of looking at this. The sockets in the kitchen
need to be on a RCD protected feed. The fixed appliances like the
oven/hob/cooker, there is no particular benefit to them being, however
there is one downside[1].
If new circuits are wired, then they will need to comply with the 17th
edition wiring regs. That means that any cables which are buried in the
building, but at a depth of = 50mm, will need some additional
protection from accidental damage. Either from a RCD, or via use of a
earthed metal shielded cable of some form (e.g. earthshield, SWA, MICC,
enclosed in steel conduit). Cables run on the surface or in surface
trunking are exempt.
RCBOs for kitchen circuits can be good, since they can be places with
highish natural leakages from all the heater elements knocking about
(oven, hob, washing machine, tumble drier, dishwasher etc).
As to the consumer unit. Much depends on what is there and whether it
has space for the required circuits or even if its still possible to get
breakers for it.
[1] The chances of your hob electrocuting you is vanishingly slim, but
the chance of an over with an ageing element nuisance tripping a RCD is
quantifiable.
As you can see we're getting very conflicting advice and whilst I'm
still waiting on all quotes coming in the two that I have range from
£800 to just over double that. So much to get a couple of quotes -
only when you know what you're doing!!!
All help very much appreciated.
Being realistic you need to look carefully at what you have and then
come up with a reasonably detailed spec for what you want. Once you have
that it will be easier getting comparable quotes (or DIYing!)
Feel free to come back with specific questions or bits you want clarified...
Other articles that may help:
http://wiki.diyfaq.org.uk/index.php?..._for_Beginners
http://wiki.diyfaq.org.uk/index.php?title=Consumer_unit
http://wiki.diyfaq.org.uk/index.php?...Consumer_Units
http://wiki.diyfaq.org.uk/index.php?title=MCB
http://wiki.diyfaq.org.uk/index.php?title=RCD
--
Cheers,
John.
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