Hello all

I have just had my kitchen drylined and now the cables entering the
backboxes are too short to be easily wired into the socket/light
switches. I'd like to just extend the cables with a chocolate box
connector (I think thats what they're called!)My question is what type
do I need, I see 30AMP big ones and other smaller ones. whats the
smallest connector I can get away with, is it dependent on the ampage
of the connected device?

Cheers

Richy

wrote in message
oups.com...
Hello all

I have just had my kitchen drylined and now the cables entering the
backboxes are too short to be easily wired into the socket/light
switches. I'd like to just extend the cables with a chocolate box
connector (I think thats what they're called!)My question is what type
do I need, I see 30AMP big ones and other smaller ones. whats the
smallest connector I can get away with, is it dependent on the ampage
of the connected device?

Cheers

Richy

you CAN extend them by any means practicable (but you should use proper
mains connector blocks which won't fit in the space available) which may in
the long run give problems and danger, but the correct and safest fix is to
rewire or pull through some slack.

mrcheerful

On 18 Dec 2004 01:01:43 -0800, wrote:

Hello all

I have just had my kitchen drylined and now the cables entering the
backboxes are too short to be easily wired into the socket/light
switches. I'd like to just extend the cables with a chocolate box
connector (I think thats what they're called!)My question is what type
do I need, I see 30AMP big ones and other smaller ones. whats the
smallest connector I can get away with, is it dependent on the ampage
of the connected device?

Cheers

Richy

Personally I'd use either crimp splices or soldered joints, covered with a couple of layers of
heatshrink. If using crimps it is absolutely essential to use a proper ratchet crimp tool, not the
cheapo plier types.

"Mike Harrison" wrote in message
...
On 18 Dec 2004 01:01:43 -0800, wrote:

Hello all

I have just had my kitchen drylined and now the cables entering the
backboxes are too short to be easily wired into the socket/light
switches. I'd like to just extend the cables with a chocolate box
connector (I think thats what they're called!)My question is what type
do I need, I see 30AMP big ones and other smaller ones. whats the
smallest connector I can get away with, is it dependent on the ampage
of the connected device?

Cheers

Richy

Personally I'd use either crimp splices or soldered joints, covered with a
couple of layers of
heatshrink. If using crimps it is absolutely essential to use a proper
ratchet crimp tool, not the
cheapo plier types.

I'm a big fan of soldered joints too for this kind of thing, but only where
I know the load is low. It is very hard to really define what power the
soldered joint will be good for.

In article ,
mrcheerful
. wrote:
you CAN extend them by any means practicable (but you should use proper
mains connector blocks which won't fit in the space available) which may
in the long run give problems and danger, but the correct and safest
fix is to rewire or pull through some slack.

Might be easy to fit extra deep boxes - 47mm - if the walls have been dry
lined?

--
*I'm planning to be spontaneous tomorrow *

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote
| you CAN extend them by any means practicable (but you should use
| proper mains connector blocks which won't fit in the space
| available)
| Might be easy to fit extra deep boxes - 47mm - if the walls have
| been dry lined?

Especially as, to keep the sockets on the ring, two lots of connectors will
be needed. Using one connector on the circuit cables and then single tails
to the socket turns the socket into an unfused spur.

Owain

mrcheerful
.. wrote:
wrote in message
oups.com...
Hello all

I have just had my kitchen drylined and now the cables entering the
backboxes are too short to be easily wired into the socket/light
switches. I'd like to just extend the cables with a chocolate box
connector (I think thats what they're called!)My question is what
type
do I need, I see 30AMP big ones and other smaller ones. whats the
smallest connector I can get away with, is it dependent on the
ampage
of the connected device?

Cheers

Richy

you CAN extend them by any means practicable (but you should use
proper
mains connector blocks which won't fit in the space available) which
may in
the long run give problems and danger, but the correct and safest fix
is to
rewire or pull through some slack.

mrcheerful

Thanks for your reply:

How big are these, do yo mean the big 30AMP connectors? The problem I
have is that the back boxes are recessed into the brick wall, I dont
have the option of fitting other deeper backboxes, pulling any slack
cable through or running any new cable. The wall is not a stud wall and
getting access under the floorboards and attempting to run new cable
would be virtually impossible as the plaster board has been dab and
dobbed (whatever you call it) Also I haven't a clue what a crimper is
and how I use one.

Thanks!

Richard

On Sat, 18 Dec 2004 11:08:05 GMT, "Scott" wrote:


"Mike Harrison" wrote in message
.. .
On 18 Dec 2004 01:01:43 -0800, wrote:

Hello all

I have just had my kitchen drylined and now the cables entering the
backboxes are too short to be easily wired into the socket/light
switches. I'd like to just extend the cables with a chocolate box
connector (I think thats what they're called!)My question is what type
do I need, I see 30AMP big ones and other smaller ones. whats the
smallest connector I can get away with, is it dependent on the ampage
of the connected device?

Cheers

Richy

Personally I'd use either crimp splices or soldered joints, covered with a
couple of layers of
heatshrink. If using crimps it is absolutely essential to use a proper
ratchet crimp tool, not the
cheapo plier types.

I'm a big fan of soldered joints too for this kind of thing, but only where
I know the load is low. It is very hard to really define what power the
soldered joint will be good for.

Soldered joints, like crimps, depend a lot on how well they are done.
A good solder/crimp is pretty much as good as the wire itself.
A bad one is way worse than choc-bloc!

On Sat, 18 Dec 2004 14:01:49 -0000, "Owain"
strung together this:

Using one connector on the circuit cables and then single tails
to the socket turns the socket into an unfused spur.

Which isn't a problem.
--

SJW
Please reply to group or use 'usenet' in email subject

In article ,
Lurch wrote:
Using one connector on the circuit cables and then single tails
to the socket turns the socket into an unfused spur.

Which isn't a problem.

Isn't there a restriction on the number of spurs from a ring?

--
*If God dropped acid, would he see people?

Dave Plowman London SW
To e-mail, change noise into sound.

Using one connector on the circuit cables and then single tails
to the socket turns the socket into an unfused spur.

Sorry to interrupt, but can I just make sure I have this clear?

As long as I don't exceed the permitted number of spurs, I can fit a
junction box into a ring circuit and take two separate single cables from it
to two separate double-sockets, and this counts as two individual spurs?

Bert
http://www.bertcoules.co.uk

"Bert Coules" wrote in message
...
Using one connector on the circuit cables and then single tails
to the socket turns the socket into an unfused spur.

Sorry to interrupt, but can I just make sure I have this clear?

As long as I don't exceed the permitted number of spurs, I can fit a
junction box into a ring circuit and take two separate single cables from
it
to two separate double-sockets, and this counts as two individual spurs?

Bert


Junction boxes are not really allowed on a final ring mains circuit. A ring
mains is rated, usually, at 32 Amps total running load, so a junction box
with terminals rated at this loading current are pretty big things. You are
allowed one fused spur from each socket on a final ring mains circuit if you
wish. To take a single cable to supply two individual double sockets that
have a total loading capability of 4 X 13 Amps = 52 Amps where the diversity
rule doesn't apply, isn't allowed.

Bert Coules wrote:

As long as I don't exceed the permitted number of spurs, I can fit a
junction box into a ring circuit and take two separate single cables from it
to two separate double-sockets, and this counts as two individual spurs?

Yes. It's certainly permitted. And a 30A junction box will allow all 4
cables to be connected pretty securely, though it's a tad tight.

Whether it's actually *smart* to run with spurs is another matter; once
you're breaking into the ring, it can be as easy to extend the ring as
to spur. If it's to supply an occasional-use socket somewhere in a
corridor or storage-only loft, a spur is the right answer almost always;
if it's to supply a double socket in a room which may end up as the
place a whole load of kit gets plugged in, I'd go the extra mile and put
them on the ring.

Stefek

Stefek,

Whether it's actually *smart* to run with spurs is another matter; once
you're breaking into the ring, it can be as easy to extend the ring as
to spur.

A good point, though this would involve using two junction boxes rather than
one. I'd have thought there's less disruption to the circuit, and therefore
less vulnerability, in using a single box with two separate cables coming
from it. I won't even have to cut the ring circuit: I can just bare and
strip the wires and lay them across the terminals (though I 'll have to cut
the earth to fit the sleeving, I suppose).

If it's to supply an occasional-use socket somewhere in a
corridor or storage-only loft, a spur is the right answer almost always...

That is the case in this instance, except that two separate sockets are
involved. Neither would be subjected to anything other than very occasional
use.

Thanks for the reply.

Bert
http://www.bertcoules.co.uk

"BigWallop" wrote in message
...

snip

Junction boxes are not really allowed on a final ring mains circuit.

How is a junction box, of the correct rating, any different to a socket ?

A ring
mains is rated, usually, at 32 Amps total running load, so a junction box
with terminals rated at this loading current are pretty big things.

Yes, but so are the terminal in the back of sockets.

The only problem with junction boxes is that many get placed in locations
that are not *readily* accessible.

Bert Coules wrote:


A good point, though this would involve using two junction boxes rather than
one. I'd have thought there's less disruption to the circuit, and therefore
less vulnerability, in using a single box with two separate cables coming
from it.

Often that's the case; but when I've done ring extenstions, I've nearly
always made at least one end of the new bit of ring replace an existing
shorter leg, running from an existing socket - if you see wot I mean.
For example, imagine there's a ring cable running between sockets in
bed2 & bed3: to add a socket on the corridor outside the two bedrooms
I'd lift boards in the more accessible bedroom, run a new length of
cable from the socket there to the new socket, and use the existing
cable from the other bedroom - possibly shortened - to complete the ring
at the new socket.

But this is effectively irrelevant to what you're doing ;-)

I won't even have to cut the ring circuit: I can just bare and
strip the wires and lay them across the terminals (though I 'll have to cut
the earth to fit the sleeving, I suppose).


Yes, many people like to keep the integrity of the "main" ring cable
this way. "Pro" sparkies (for whom time-to-complete is a driving issue)
will rarely bother, and are less likely to be wimpy about tightening the
terminals in any fitting ;-)


.................................................. two separate sockets are
involved. Neither would be subjected to anything other than very occasional
use.

Then I'd have no qualms in running with the single JB approach; remember
to leave the JB nominally "accessible", i.e. if under floorboards, mark
the location and replace boards with screw-not-nails; if in some other
void, provide some form of maintenance access.

Stefek

BigWallop wrote:

Junction boxes are not really allowed on a final ring mains circuit. A ring
mains is rated, usually, at 32 Amps total running load, so a junction box
with terminals rated at this loading current are pretty big things. You are
allowed one fused spur from each socket on a final ring mains circuit if you
wish. To take a single cable to supply two individual double sockets that
have a total loading capability of 4 X 13 Amps = 52 Amps where the diversity
rule doesn't apply, isn't allowed.

Yeah but no but yeah but no but no, actually.

Adequately-rated JBs are perfectly allowable on ring circuits, and
available from all the usual suppliers in not-particularly-monstrous
sizes. Larger than yer 20A lighting JBs, but not vastly more
(half-as-big-again in diameter is typical, with MK doing a more
robust-looking rectangular one. Or at least they used to!)

Yes, there's guidance to restrict the number of spurred sockets-n-FCUs
to no more than the number of non-spurred-sockets-n-FCUs; it's not a
strict engineering limit (as in, house will catch fire if one more spur
added), rather a guideline to keep rings basically as rings, rather than
silly pseudo-rings with a positively daft number of spurred-off
accessories. In a domestic setting, the odd spur or two can make perfect
sense; in a commercial/industrial one, where loading of individual
points is much harder to anticipate, spurs are much less likely to be a
Good Idea.

As for "double socket = 26A" (even if you incant away diversity) - it
would be a most unusual situation in which 26A were really drawn, and
AFAIK even the best manufacturers design their doubles with the
assumption of no more than 20A loading. The point you make about a
single cable running to two separate sockets is quite correct: the
reasoning for it is more clearly demonstrated when they're double
sockets, but though there used to be a 'concession' to say 'well, two
separate *singles* can go on one unfused spur run', that notion dies a
death in the ?15th? Edition, presumably (a) because the single could
readily be changed to a double later on, (b) it meant "two cables
running to this socket so it must be on the ring" was untrue.

Stefek,

Thanks for the reply.

Remember to leave the JB nominally "accessible"...

Though I know this is recommended (and I will do it) I do wonder exactly
why. Apart from a total rewiring job, the only reason I can think of for
ever needing to get to the junction box again would be if the terminals
needed to be re-tightened. Is this likely? And in any case, how would I
know that it needed to be done? Are there recognisable symptoms?

Bert
http://www.bertcoules.co.uk

Bert Coules wrote:


Though I know this is recommended (and I will do it) I do wonder exactly
why. Apart from a total rewiring job, the only reason I can think of for
ever needing to get to the junction box again would be if the terminals
needed to be re-tightened. Is this likely? And in any case, how would I
know that it needed to be done? Are there recognisable symptoms?

The fresh scent of ozone, maybe a little carbonising ;-) The
refinement-in-practice of the "good workmanship" principle of the Regs
is that all "non-permanent" joints ought to be accessible, for testing
and repair. In particular, testing of the integrity of a ring (making
sure that it still is one every few years!) is when you want the
accessibility - to be more specific, it's when you find anomalous
results from such testing that you want to get at successive points on
the ring, and since problems at connection points totally dominate the
likely faults (not that many titanium-toothed rats around ;-) that's the
reason for keeping all connection points accessessabubble.

In practice, if you do the connections up sensibly tight in the first
place, and avoid silly squashing and overtight bending of the conductors
(and any repeated movement of the cables, naturally), your screwed
connections will be find for 40 years or more...

Stefek

On Sun, 19 Dec 2004 14:48:48 -0000, "Bert Coules"
strung together this:

Are there recognisable symptoms?

Yes, smoke starts coming up from between the floorboards!
--

SJW
Please reply to group or use 'usenet' in email subject

"Stefek Zaba" wrote
| As long as I don't exceed the permitted number of spurs, I can
| fit a junction box into a ring circuit and take two separate
| single cables from it to two separate double-sockets, and this
| counts as two individual spurs?
| Yes. It's certainly permitted.

Are you sure? I would have said 'no' on the grounds that it is putting a
high point load on the ring; no more than one double socket or one FCU
should be taken from each point on the ring. Of course, if there're only 12"
between 2 points each feeding a spur the 'rule' has been complied with but
the principle ignored.

Owain

On Sun, 19 Dec 2004 12:43:37 -0000, "Bert Coules"
strung together this:

As long as I don't exceed the permitted number of spurs, I can fit a
junction box into a ring circuit and take two separate single cables from it
to two separate double-sockets, and this counts as two individual spurs?

Yes, and no.
I've done this before as it saves breaking the cable in more than one
place, and as we know connections = resistance = bad.
You're not actually meant to, so don't listen to me and do it to the
regs, which means more joints, more resistance and more junction
boxes.
--

SJW
Please reply to group or use 'usenet' in email subject

Lurch,

...so don't listen to me and do it to the regs...

I wouldn't dream of doing anything else. Many thanks.

Bert
http://www.bertcoules.co.uk

"Bert Coules" writes:

once you're breaking into the ring, it can be as easy to extend
the ring as to spur.

A good point, though this would involve using two junction boxes
rather than one.

If you're extending a 30A ring then the terminals only need to be
rated at 20A each (just as would be the case if you could fit all the
conductors in for your two spurs) and you can get six of them in one
box, e.g. URL:http://www.tlc-direct.co.uk/Products/AAJB206.html.

--
Mark

Mark Williams wrote:


If you're extending a 30A ring then the terminals only need to be
rated at 20A each

Hard to justify quite such a penny-pinching way of going about things!
It's not hard to come up with reasonable scenarios in which the
terminals are called on to pass over 20A - e.g. the spur drawing 15A and
other sockets on the ring drawing 15A at such positions as to cause,
say, 2/3 of that load to flow through the JB we're talking of. While
it's imaginable to use 20A terminals safely, and quite possible to louse
up the use of 30A terminals by having too little effective contact area
for the conductors, I'd consider it irresponsible to use anything lower
rated than 30A. In any case the OP (like the half-orphaned growing lad
in the furniture-out-of-the-window "if they're anything kangaroos" joke)
needs all the room he can get, whereas the JB you point to as well as
having only 20A-rated terms has 6 of them taking up the precious room.
And what did you want him to do with the other 3? He only needs E L & N.
Running short strappers to get two of the 6 terms for each of the 3 ways
only reduces the number of cores in each terminal by 1 - you'll still
have two "real" cores and the strapper - and introduces more
connections. Bodgesville magna.

Stefek

On Sun, 19 Dec 2004 20:03:10 GMT, Mark Williams
] strung together this:

If you're extending a 30A ring then the terminals only need to be
rated at 20A each

Er, no.
--

SJW
Please reply to group or use 'usenet' in email subject

Mark Williams ] writes:

(just as would be the case if you could fit all the conductors in
for your two spurs)

Sorry, this bit is wrong. It's a good thing they probably wouldn't
all fit, isn't it :-)!

--
Mark

Lurch writes:

If you're extending a 30A ring then the terminals only need to be
rated at 20A each

Er, no.

How so?

--
Mark

Mark Williams wrote:

If you're extending a 30A ring then the terminals only need to be
rated at 20A each (just as would be the case if you could fit all the
conductors in for your two spurs) and you can get six of them in one
box...

I wasn't objecting to the expense! My point - as I thought was clear - was
that I'd always been led to believe that there should be as few breaks in
the ring circuit as possible, and so one was better than two.

Bert
http://www.bertcoules.co.uk

If you're extending a 30A ring then the terminals only need to be
rated at 20A each

Er, no.

Why so? If the cable only needs to be rated at 20A, why should the junction
boxes have to be rated higher? Not that I would use them myself, though. 30A
makes more sense, but I don't see why 20A would not be permitted.

Christian.

On Mon, 20 Dec 2004 11:19:46 -0000, "Christian McArdle"
strung together this:

Why so? If the cable only needs to be rated at 20A, why should the junction
boxes have to be rated higher? Not that I would use them myself, though. 30A
makes more sense, but I don't see why 20A would not be permitted.

Now I've actually thought about it, I meant to say what you said
Christian!
The ''er, no'' bit was personal preference.
--

SJW
Please reply to group or use 'usenet' in email subject