I want to add extra sockets in my kitchen. I have numerous double sockets
on the ring with the two mains cables embedded in plaster and descending
from the ceiling. However, I need to add more sockets at a couple of these
locations.

A sparkie mate of mine says that this must be done by
extending the ring main - no more than one spur off each socket. Ok -
understood. The way to do this, he told me was to take one of the
descending cables from this master socket and use choc block to connect it
to a cable going to the first new socket. The return cable from this
secondary socket will connect to the terminals of the master socket,
together with the other descending cable, thus keeping the ring intact.

Does this sound OK - just sounding this idea out. Or do I have to do
complete new cabling and have the floorboards up upstairs?

--
===============================================
Thanks,

Steve

"There are only two tragedies in life: one is not getting what one wants, and the other is getting it". Oscar Wilde

Use ROT13 for my email:

"Kaiser Sose" wrote in message
...
I want to add extra sockets in my kitchen. I have numerous double sockets
on the ring with the two mains cables embedded in plaster and descending
from the ceiling. However, I need to add more sockets at a couple of
these
locations.

Going to ignore the obvious Part P implications and the choc block
implications.

Think you might have slightly misunderstood something your sparkie said....

A sparkie mate of mine says that this must be done by
extending the ring main - no more than one spur off each socket. Ok -
understood.

Not quite. You can have one spur off each ring connected socket. No need
for choc block if done that way. What you sparkie explained was how HE
would extend the ring.

Jim A

On Wed, 07 Mar 2007 06:09:43 -0600 someone who may be Kaiser Sose
wrote this:-

A sparkie mate of mine says that this must be done by
extending the ring main - no more than one spur off each socket. Ok -
understood. The way to do this, he told me was to take one of the
descending cables from this master socket and use choc block to connect it
to a cable going to the first new socket. The return cable from this
secondary socket will connect to the terminals of the master socket,
together with the other descending cable, thus keeping the ring intact.

Nothing wrong with using terminal blocks in this way, though the box
needs to be large enough to accommodate them and the socket.

Any ring circuit that has been extended should be tested properly to
ensure that it is still a ring.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

"David Hansen" wrote in message
news
On Wed, 07 Mar 2007 06:09:43 -0600 someone who may be Kaiser Sose
wrote this:-

A sparkie mate of mine says that this must be done by
extending the ring main - no more than one spur off each socket. Ok -
understood. The way to do this, he told me was to take one of the
descending cables from this master socket and use choc block to connect it
to a cable going to the first new socket. The return cable from this
secondary socket will connect to the terminals of the master socket,
together with the other descending cable, thus keeping the ring intact.

Nothing wrong with using terminal blocks in this way, though the box
needs to be large enough to accommodate them and the socket.

Any ring circuit that has been extended should be tested properly to
ensure that it is still a ring.

Yes very true, and I would test it before extending as well. You can open a
right can of worms if you only test afterwards.

Adam

snip

Thanks for the updates guys.

If I were to use choc block in the way I described, would I have to wrap it
in insulating tape before pushing it to the back of the (metal) 45mm deep
socket box? If so, do the regulations prescribe a particular colour of
tape?

Also, how to test the continuity of the ring as mentioned? Just buzz it
out with a bleeper? On that note, how to tell whether the ring is
complete before I even start? I would guess that if I disconnected the
two main cables from an existing ring socket and put a buzzer lead on each
one of the three conductors in turn they should still buzz out at 0 ohms
back through the consumer unit?????

Thanks,

Steve


Use ROT13 for my email:

Kaiser Sose wrote:

If I were to use choc block in the way I described, would I have to wrap it
in insulating tape before pushing it to the back of the (metal) 45mm deep
socket box? If so, do the regulations prescribe a particular colour of
tape?

No need since it is already contained in an enclosure.

Also, how to test the continuity of the ring as mentioned? Just buzz it
out with a bleeper? On that note, how to tell whether the ring is
complete before I even start? I would guess that if I disconnected the
two main cables from an existing ring socket and put a buzzer lead on each
one of the three conductors in turn they should still buzz out at 0 ohms
back through the consumer unit?????

Yup, that is the sort of idea...

The following procedure is not a replacement for the full tests descibed
in the On-Site Guid, but will give you a good confidence check on the
new wiring.

Let's assume you have installed the new bit of ring and wired it all up
but not connected it yet.

Turn off the power to the circuit, and unplug (or otherwise isolate) all
the things plugged into the circuit. Disconnect the existing socket,
then separate out the wires. Using a multimeter on a low ohms resistance
range you can measure the resistance between the two lives, neutrals and
earths. You would expect live to live and neutral to neutral readings to
be the same as each other, and the earth to earth may be a little higher
(since the wire is thinner). Note the resistances.

Now carry out the same test on the new ring and note the results. You
can also do a R1+R2 type test where you measure the combined resistance
of the live and the earth wire together. This will enable you to compare
your results against table 9A in the OSG. Since you probably have a good
idea how long the new ring section is, you can use this as a sanity
check. If you have access to a megger you could also use this on the new
section of circuit to check its insulation resistance is also ok.

Now make the cable join between old and new wires (using up two of your
four free cables). Check the round trip resistance between the remaining
ends. This should now be checking the resistance of the whole circuit.
You would expect a reading equal to the sum of the previous readings
that you made for the old and new bits in isolation. You should now have
good confidence that the new cable to cable join is good. Finally
replace the original socket and connect the remaining two cables to it
in the normal way.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Kaiser Sose wrote:

A sparkie mate of mine says that this must be done by
extending the ring main - no more than one spur off each socket. Ok -
understood. The way to do this, he told me was to take one of the
descending cables from this master socket and use choc block to connect it
to a cable going to the first new socket. The return cable from this
secondary socket will connect to the terminals of the master socket,
together with the other descending cable, thus keeping the ring intact.

It sounds like you may be confusing two different ways of extending the
circuit... (there is also a third - which we will come to)

an unfused spur:

Here you can feed one (and no more than one) socket (single or double)
via a single cable from an exiting socket (or other appropriate
accessory) on an exiting ring. These are simple to wire and require no
cable to cable joints, however you may not be able to get enough sockets
added in this way.

Extending the ring:

If you need to add many new sockets then this is a better solution. The
technique described by your sparkie is one way (I usually use crimped
connections since they take less space in the back box, and are more
"permanent"). Splitting the ring elsewhere with a pair of junction boxes
would be another way.

A fused spur:

A third way to add several sockets is via fused spur. Here you wire a
fused connection unit to the existing ring as a spur. Then wire as many
sockets as you require from this. It is often an easy way to get extra
sockets, but the big limitation is that all the added sockets will have
to share the single 13A fused supply - so it is not appropriate for
sockets that you anticipate carrying heavy loads.



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"Kaiser Sose" wrote in message
...
I want to add extra sockets in my kitchen. I have numerous double sockets
on the ring with the two mains cables embedded in plaster and descending
from the ceiling. However, I need to add more sockets at a couple of
these
locations.

A sparkie mate of mine says that this must be done by
extending the ring main - no more than one spur off each socket. Ok -
understood. The way to do this, he told me was to take one of the
descending cables from this master socket and use choc block to connect it
to a cable going to the first new socket. The return cable from this
secondary socket will connect to the terminals of the master socket,
together with the other descending cable, thus keeping the ring intact.

Does this sound OK - just sounding this idea out. Or do I have to do
complete new cabling and have the floorboards up upstairs?

--
OK, here's another angle. You have numerous double sockets and want more
sockets at a couple of these locations. Actually the addition process is
more to do with the ring connection between existing sockets that the
dropper. You need to work out where the run is. Assuming the socket
boxes are also embedded in plaster, initially assume horizontal or vertical
cabling but the socket boxes may yield a clue. If so maybe you can insert a
socket box between two existing sockets and chase between the sockest to
repair the ring. Understanding the route of the ring is the key.

Jim A