In my house, the previous occupant has done all sorts of terrible things with the electrics, the shower (9.5kW) fed with 2.5mm to name just one!

The lates bodge found was behind a wall cabinet. At one time, there used to
be a double mains socket, which has been removed complete with back box and
replaced with a standard round junction box. The hole has been gouged out to
allow it to be sunk. From this, a short spur to a new, lower position.

My requirement is to open the ring at this point and run another couple or
three of sockets. I know that crimps are the way to go, but tell me this:

1) Are these crimps the same blue ones as I use for auto electrical work?

2) Should the earth be connected straight through, or connected to a
replacement back box (removed during this bodge).


--
AJL Electronics (G6FGO) Ltd : Satellite and TV aerial systems
http://www.classicmicrocars.co.uk : http://www.ajlelectronics.co.uk

In article ,
Andy Luckman (AJL Electronics) wrote:
My requirement is to open the ring at this point and run another couple
or three of sockets. I know that crimps are the way to go, but tell me
this:

1) Are these crimps the same blue ones as I use for auto electrical
work?

2) Should the earth be connected straight through, or connected to a
replacement back box (removed during this bodge).

If you replace the back box it then becomes 'accessible' so you could use
choc blocks for the connectors and fit a blank plate as a cover. I don't
think it matters that it's behind a cupboard.

I don't like those blue crimpy things. ;-)

--
*It sounds like English, but I can't understand a word you're saying.

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

snip
1) Are these crimps the same blue ones as I use for auto electrical work?

No - those are for low voltage, multi-strand wire. T&E is not.

You'd need crimps designed for the wire size and current - probably the
yellow coupler type ones, and a proper (ratchet) crimp tool to close them
properly - not the el cheapo ones which cannot apply enough force.

Alan.

"Alan" wrote in message
...
snip
1) Are these crimps the same blue ones as I use for auto electrical work?

No - those are for low voltage, multi-strand wire. T&E is not.

You'd need crimps designed for the wire size and current - probably the
yellow coupler type ones, and a proper (ratchet) crimp tool to close them
properly - not the el cheapo ones which cannot apply enough force.

Alan.
AFAIK there is no difference in contrsuction between the blue/red and yellow
bullets. The only difference is the size of them so I can't see how one
would be for stranded and another solid. Definatly agree that its worth
getting the proper crimpers if you are going to use them

In article ,
Alan wrote:
1) Are these crimps the same blue ones as I use for auto electrical
work?

No - those are for low voltage, multi-strand wire. T&E is not.

I can't see any difference between ones bought from Halfords or from TLC.
Neither does RS etc list ones for low voltage stranded and mains solid
core - and they of course would cover both events with their products.

You'd need crimps designed for the wire size and current - probably the
yellow coupler type ones, and a proper (ratchet) crimp tool to close
them properly - not the el cheapo ones which cannot apply enough force.

TLC give red 1.5mm
blue 2.5mm
yellow 6.0mm

So for coupling 2.5mm blue is correct.

--
*Succeed, in spite of management *

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

In article , Alan
wrote:

You'd need crimps designed for the wire size and current - probably the
yellow coupler type ones, and a proper (ratchet) crimp tool to close them
properly - not the el cheapo ones which cannot apply enough force.

I have some proper tools, all I need then is the yellow crimps, CPC? or
Dave's suggestion of chocolate blocks. I am going to make it accessible ish,
so I suppose that's OK.

--
AJL Electronics (G6FGO) Ltd : Satellite and TV aerial systems
http://www.classicmicrocars.co.uk : http://www.ajlelectronics.co.uk

"Dave Plowman (News)" wrote in message
...
In article ,
Alan wrote:
1) Are these crimps the same blue ones as I use for auto electrical
work?

No - those are for low voltage, multi-strand wire. T&E is not.

I can't see any difference between ones bought from Halfords or from TLC.
Neither does RS etc list ones for low voltage stranded and mains solid
core - and they of course would cover both events with their products.

You'd need crimps designed for the wire size and current - probably the
yellow coupler type ones, and a proper (ratchet) crimp tool to close
them properly - not the el cheapo ones which cannot apply enough force.

TLC give red 1.5mm
blue 2.5mm
yellow 6.0mm

So for coupling 2.5mm blue is correct.


I though the OP was referring to the "Scotch" or "Snap-lock" type blue
connector often used in car wiring mods, like this:

http://www.maplin.co.uk/Module.aspx?...1073&doy=13m6D

Alan.

"Rob Convery" wrote in message
...

"Alan" wrote in message
...
snip
1) Are these crimps the same blue ones as I use for auto electrical
work?

No - those are for low voltage, multi-strand wire. T&E is not.

You'd need crimps designed for the wire size and current - probably the
yellow coupler type ones, and a proper (ratchet) crimp tool to close them
properly - not the el cheapo ones which cannot apply enough force.

Alan.
AFAIK there is no difference in contrsuction between the blue/red and
yellow bullets. The only difference is the size of them so I can't see how
one would be for stranded and another solid. Definatly agree that its
worth getting the proper crimpers if you are going to use them



I though the OP was referring to the "Scotch" or "Snap-lock" type blue
connector often used in car wiring mods, like this:

http://www.maplin.co.uk/Module.aspx?...1073&doy=13m6D

Alan.

In article ,
Alan wrote:
I though the OP was referring to the "Scotch" or "Snap-lock" type blue
connector often used in car wiring mods, like this:

I'd sincerely hope not. Dreadful bodges. And they're not crimps but a
crude IPC type.

--
*Money isn't everything, but it sure keeps the kids in touch.

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

In article ,
Dave Plowman (News) wrote:

I can't see any difference between ones bought from Halfords or
from TLC. Neither does RS etc list ones for low voltage stranded
and mains solid core - and they of course would cover both events
with their products.

I would be cautious about crimps, unless the blurb
actually said the word 'solid'.

For example, I assume that all RS crimps are for
stranded wire, with the only exception being the
range from Solistrand, whose blurb actually does
say "designed for solid, stranded, and irregular
shaped copper conductors".

The Solistrands are uninsualated crimps, of a thicker
gauge copper than usual, with heavy serrations down
the bore, presumably to bite into solid copper wires.

--
Tony Williams.

In article , "Andy Luckman
(AJL Electronics)" writes
In article , Alan
wrote:

You'd need crimps designed for the wire size and current - probably the
yellow coupler type ones, and a proper (ratchet) crimp tool to close them
properly - not the el cheapo ones which cannot apply enough force.

I have some proper tools, all I need then is the yellow crimps, CPC? or
Dave's suggestion of chocolate blocks. I am going to make it accessible ish,
so I suppose that's OK.

I can't see what's wrong with the original round junction box set into
the wall. Why is using choc block better than that?
--
Tim Mitchell

In article ,
Tony Williams wrote:
I can't see any difference between ones bought from Halfords or
from TLC. Neither does RS etc list ones for low voltage stranded
and mains solid core - and they of course would cover both events
with their products.

I would be cautious about crimps, unless the blurb
actually said the word 'solid'.

The 'standard' red blue and yellow pre-insulated types make no mention of
this anywhere I've seen them on sale.

And I'd expect Halfords to sell them for car use - ie flex, and TLC for
mains cable - ie solid in the smaller sizes. Or at least to state if they
were only for use with flex.

--
*The more I learn about women, the more I love my car

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

In article , Alan
wrote:


I though the OP was referring to the "Scotch" or "Snap-lock" type blue
connector often used in car wiring mods, like this:

No no no. I said "auto electrics", not firestarters. :-)

--
AJL Electronics (G6FGO) Ltd : Satellite and TV aerial systems
http://www.classicmicrocars.co.uk : http://www.ajlelectronics.co.uk

In article , Tim Mitchell
wrote:

I can't see what's wrong with the original round junction box set into
the wall. Why is using choc block better than that?

Because I want to open the ring at that point. There are insufficient
terminals in the box.

--
AJL Electronics (G6FGO) Ltd : Satellite and TV aerial systems
http://www.classicmicrocars.co.uk : http://www.ajlelectronics.co.uk

On Mon, 13 Jun 2005 10:02:48 +0100, "Andy Luckman (AJL Electronics)"
wrote:

1) Are these crimps the same blue ones as I use for auto electrical work?

2) Should the earth be connected straight through, or connected to a
replacement back box (removed during this bodge).

As has been said further down this thread, the crimps you'd need to
use would be the blue 'butt splice' ones, using a decent crimp tool.

However, seeing as you're planning to use a new backbox anyway, my
suggestion would be to go with choc block strip connector because it
allows you more control over the connection strength.

The earth should go to the new box at at least one point.



--
"I think computer viruses should count as life. I think it
says something about human nature that the only form of life
we have created so far is purely destructive. We've created
life in our own image." - Stephen Hawking

In article ,
Chipmunk wrote:
However, seeing as you're planning to use a new backbox anyway, my
suggestion would be to go with choc block strip connector because it
allows you more control over the connection strength.

The earth should go to the new box at at least one point.

Yup - but I'd use a choc block for the main earth connection and just run
a tail to the box terminal.

--
*If you think nobody cares about you, try missing a couple of payments *

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

On Mon, 13 Jun 2005 13:36:06 +0100, "Dave Plowman (News)"
wrote:

I would be cautious about crimps, unless the blurb
actually said the word 'solid'.

The 'standard' red blue and yellow pre-insulated types make no mention of
this anywhere I've seen them on sale.

Crimps are relatively non-fussy about stranded vs. colid core cable. For
most combinations the same crimp terminal can be used, although the
ideal crimping force is slightly different.

If you're using pre-insulated crimps (ghastly things that they are) then
the vagaries of trying to deliver a controlled force through a squashy
plastic sleeve give rise to far more variation than solid/stranded
cable.

In article ,
Andy Dingley wrote:
The 'standard' red blue and yellow pre-insulated types make no mention of
this anywhere I've seen them on sale.

Crimps are relatively non-fussy about stranded vs. colid core cable. For
most combinations the same crimp terminal can be used, although the
ideal crimping force is slightly different.

If you're using pre-insulated crimps (ghastly things that they are) then
the vagaries of trying to deliver a controlled force through a squashy
plastic sleeve give rise to far more variation than solid/stranded
cable.

Yup - never use them these days on cars. I bought the proper crimping tool
for Lucar connectors from Vehicle Wiring Products, so now use crimp
connectors exactly the same as the makers ones.

--
*Time is fun when you're having flies... Kermit

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

"Alan" wrote in message
...

"Rob Convery" wrote in message
...

"Alan" wrote in message
...
snip
1) Are these crimps the same blue ones as I use for auto electrical
work?

No - those are for low voltage, multi-strand wire. T&E is not.

You'd need crimps designed for the wire size and current - probably the
yellow coupler type ones, and a proper (ratchet) crimp tool to close
them
properly - not the el cheapo ones which cannot apply enough force.

Alan.
AFAIK there is no difference in contrsuction between the blue/red and
yellow bullets. The only difference is the size of them so I can't see
how
one would be for stranded and another solid. Definatly agree that its
worth getting the proper crimpers if you are going to use them



I though the OP was referring to the "Scotch" or "Snap-lock" type blue
connector often used in car wiring mods, like this:

http://www.maplin.co.uk/Module.aspx?...1073&doy=13m6D

Alan.

So did I Alan. :-)

On Mon, 13 Jun 2005 10:02:48 +0100, "Andy Luckman (AJL Electronics)"
wrote:


In my house, the previous occupant has done all sorts of terrible things with the electrics, the shower (9.5kW) fed with 2.5mm to name just one!

The lates bodge found was behind a wall cabinet. At one time, there used to
be a double mains socket, which has been removed complete with back box and
replaced with a standard round junction box. The hole has been gouged out to
allow it to be sunk. From this, a short spur to a new, lower position.

My requirement is to open the ring at this point and run another couple or
three of sockets. I know that crimps are the way to go, but tell me this:

1) Are these crimps the same blue ones as I use for auto electrical work?

I'd consider using those on solid core to be a bodge, however they're
crimped.

I'd only use ones specifically designed for solid core and crimped in
the recommended way.

cheers,
Pete.

In article ,
Alan wrote:
I though the OP was referring to the "Scotch" or "Snap-lock" type blue
connector often used in car wiring mods, like this:

http://www.maplin.co.uk/Module.aspx?...1073&doy=13m6D

But it's only rated at 8 amps. Doubt if even Dimm would use one of those
for ring main cable.

--
*I didn't fight my way to the top of the food chain to be a vegetarian.

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

"Dave Plowman (News)" wrote in message
...
In article ,
Alan wrote:
I though the OP was referring to the "Scotch" or "Snap-lock" type blue
connector often used in car wiring mods, like this:

http://www.maplin.co.uk/Module.aspx?...1073&doy=13m6D

But it's only rated at 8 amps. Doubt if even Dimm would use one of those
for ring main cable.


I dunno - would probably be ideal for splitting a mains cable to feed 2
combi boilers...

On Mon, 13 Jun 2005 11:53:21 +0100, "Andy Luckman (AJL Electronics)"
wrote:


You'd need crimps designed for the wire size and current - probably the
yellow coupler type ones, and a proper (ratchet) crimp tool to close them
properly - not the el cheapo ones which cannot apply enough force.

I have some proper tools, all I need then is the yellow crimps, CPC? or
Dave's suggestion of chocolate blocks. I am going to make it accessible ish,
so I suppose that's OK.

Either are good, in industry crimps are used to save time.

You can break up the chock-block connectors and push them into the
corners, tape them up with insulation tape if it makes you feel
better. Remember this is a ring circuit, therefore their should not
be any connection between the CPC, Phase or neutrals between each
leg.

This is better explained in the IEE On-Site guide.

J

John_ZIZinvalid wrote:

...... Remember this is a ring circuit, therefore there should not
be any connection between the CPC, Phase or neutrals between each
leg.

Come again, chuck? Are you trying to say 'keep it as a ring, don't end
up with a multi-socket spur, you want a 'goes in' and a 'comes back' leg
to your new sockets and they should be separate in the weirdo backbox' -
in which case, yes you're right, and Andy L prolly knows already. If
not, could you explain what you did have in mind?

This extending-for-new-sockets topic came up a couple of weeks ago. One
of the nicest solutions was to use a dual box, to mount two singles side
by side, each with one of the old ring cables and a leg of the new bit
of ring. No chocbloc, room to breathe, and general Goodness all round...

Stefek

"Stefek Zaba" wrote in message
...
John_ZIZinvalid wrote:

...... Remember this is a ring circuit, therefore there should not
be any connection between the CPC, Phase or neutrals between each
leg.

Come again, chuck? Are you trying to say 'keep it as a ring, don't end
up with a multi-socket spur, you want a 'goes in' and a 'comes back' leg
to your new sockets and they should be separate in the weirdo backbox' -
in which case, yes you're right, and Andy L prolly knows already. If
not, could you explain what you did have in mind?

This extending-for-new-sockets topic came up a couple of weeks ago. One
of the nicest solutions was to use a dual box, to mount two singles side
by side, each with one of the old ring cables and a leg of the new bit
of ring. No chocbloc, room to breathe, and general Goodness all round...

Stefek

But all this is hidden behind a cabinet or cupboard, which sounds built-in
to the kitchen scheme.

In article ,
Andy Dingley wrote:

I would be cautious about crimps, unless the blurb
actually said the word 'solid'.

Crimps are relatively non-fussy about stranded vs. colid core
cable. For most combinations the same crimp terminal can be used,
although the ideal crimping force is slightly different.

Bare copper is a reactive metal, subject to long term
oxidation, or verdigris, or other chemical attack.
To make a reliable crimp joint onto bare copper needs
something that first of all cuts through any oxidation
that may be there, and then makes a gas-tight connection.

This needs a heavy gauge crimp, with sharp serrations
down the bore, used with the correct tool.

If you're using pre-insulated crimps (ghastly things that they
are) then the vagaries of trying to deliver a controlled force
through a squashy plastic sleeve give rise to far more variation
than solid/stranded cable.

Add to that pre-insulated crimps in a light gauge
with smooth bore, or at best rounded crinkles down
the bore.

--
Tony Williams.

In article , BigWallop
wrote:


But all this is hidden behind a cabinet or cupboard, which sounds built-in
to the kitchen scheme.

I was very careful NOT to mention the K word. It could be in
a bedroom. :-)

--
AJL Electronics (G6FGO) Ltd : Satellite and TV aerial systems
http://www.classicmicrocars.co.uk : http://www.ajlelectronics.co.uk

On Mon, 13 Jun 2005 23:48:25 +0100, Stefek Zaba
wrote:

...... Remember this is a ring circuit, therefore there should not
be any connection between the CPC, Phase or neutrals between each
leg.

Come again, chuck? Are you trying to say 'keep it as a ring, don't end
up with a multi-socket spur, you want a 'goes in' and a 'comes back' leg
to your new sockets and they should be separate in the weirdo backbox' -
in which case, yes you're right, and Andy L prolly knows already. If
not, could you explain what you did have in mind?

Yes. Keep within the ring where possible, and don't cross connect
between both legs, this is better explained in the IEE On-Site guide
with the aid of diagrams.

I don't have a copy of the IEE Regs here with me, so cannot state the
exact IEE regulation rule, but there is a rule which states the amount
of spurs you can have on ring, and that spured sockets should not
exceed the amount of sockets which make up the ring.

You are also limited to the amount of sockets on a spur, and these
should not exceed one double/single, if you want more then you need
to install a fused spur.

This extending-for-new-sockets topic came up a couple of weeks ago. One
of the nicest solutions was to use a dual box, to mount two singles side
by side, each with one of the old ring cables and a leg of the new bit
of ring. No chocbloc, room to breathe, and general Goodness all round...

Your solution of using two single sockets side by side is a good way
of solving the problem, rather than using connectors and one
double/single socket.

J

In article ,
John_ZIZinvalid writes:

I don't have a copy of the IEE Regs here with me, so cannot state the
exact IEE regulation rule, but there is a rule which states the amount
of spurs you can have on ring, and that spured sockets should not
exceed the amount of sockets which make up the ring.

That's a recommendation in the On-Site Guide only.
It's not part of the Wiring Regulations.

I suspect it is because there are rarely if any spurs on
a newly installed ring, and if you get the the point where
you've doubled the number of points on a ring circuit with
spurs, you really should be looking at rewiring it to meet
your current needs, as the original design is clearly no
longer appropriate to current usage.

--
Andrew Gabriel

Tony Williams wrote:
In article ,
Andy Dingley wrote:


I would be cautious about crimps, unless the blurb
actually said the word 'solid'.


Crimps are relatively non-fussy about stranded vs. colid core
cable. For most combinations the same crimp terminal can be used,
although the ideal crimping force is slightly different.


Bare copper is a reactive metal, subject to long term
oxidation, or verdigris, or other chemical attack.
To make a reliable crimp joint onto bare copper needs
something that first of all cuts through any oxidation
that may be there, and then makes a gas-tight connection.

This needs a heavy gauge crimp, with sharp serrations
down the bore, used with the correct tool.

How then are screw terminals acceptable? Normally these are just the
means of fixing the wire into the terminal - not the main conductor. A
screw point is not terribly big, so I wouldn't expect it to remove a
significant amount of oxidation when screwed up - especially if two
wires are present (eg. ring main in back of socket, where the screws
tend to be smaller than, say a junction box). Much of the main contact
is by the surrounding metal in the terminal - which doesn't have any
means of removing oxidation etc. Then there's the secondary problem of
the screws coming lose over time and the fact that a round wire doesn't
perfectly fill a square hole, so not all the copper wire is in contact
with the terminal (made worse when running a spur from a ring where you
have 3 wires in a termainal).

I agree that in most case, you'll probably find that a standard crimp
doesn't cover the oxidation issue - but I don't believe many other
common fixings (other than soldering) make much, if any, attempt at
doing his either. At least with crimps you have a better mechanical
joint than screws, practically all the external surface of the wire is
in contact with the crimp - and I'd doubt the electrical joint was
significantly worse than a screw terminal. Based on that, a crimp joint
seems better, or am I missing anything?

D

Tony Williams wrote:
In article ,
Dave Plowman (News) wrote:

I can't see any difference between ones bought from Halfords or
from TLC. Neither does RS etc list ones for low voltage stranded
and mains solid core - and they of course would cover both events
with their products.

I would be cautious about crimps, unless the blurb
actually said the word 'solid'.

For example, I assume that all RS crimps are for
stranded wire, with the only exception being the
range from Solistrand, whose blurb actually does
say "designed for solid, stranded, and irregular
shaped copper conductors".

The Solistrands are uninsualated crimps, of a thicker
gauge copper than usual, with heavy serrations down
the bore, presumably to bite into solid copper wires.

I don't see how the type of wire affects how well the crimp works
really. The copper in stranded wire can creep (or not) to exactly the
same extent as the copper in non-stranded wire.

My crimps came from my local Electrical Wholesaler so presumably are
designed for use with mains cable, the cataloge certainly implies that
is their intended use.

--
Chris Green

Pete C wrote:
On Mon, 13 Jun 2005 10:02:48 +0100, "Andy Luckman (AJL Electronics)"
wrote:


In my house, the previous occupant has done all sorts of terrible things with the electrics, the shower (9.5kW) fed with 2.5mm to name just one!

The lates bodge found was behind a wall cabinet. At one time, there used to
be a double mains socket, which has been removed complete with back box and
replaced with a standard round junction box. The hole has been gouged out to
allow it to be sunk. From this, a short spur to a new, lower position.

My requirement is to open the ring at this point and run another couple or
three of sockets. I know that crimps are the way to go, but tell me this:

1) Are these crimps the same blue ones as I use for auto electrical work?


I'd consider using those on solid core to be a bodge, however they're
crimped.

I'd only use ones specifically designed for solid core and crimped in
the recommended way.

Ok. I've read enough of this thread to feel nervous. I have crimped
some 1.5T&E with some blue crimps and a ratchet crimping tool. If these
crimps are not correct for the job, can someone point me to some that
are? I have never heard of mains-rated crimps.

Antony

In article ,
antgel wrote:
Ok. I've read enough of this thread to feel nervous. I have crimped
some 1.5T&E with some blue crimps and a ratchet crimping tool. If these
crimps are not correct for the job, can someone point me to some that
are? I have never heard of mains-rated crimps.

Think red is the right size for 1.5mm.

But any crimped joint doesn't really consider the voltage. It's the
current that matters. The insulation must be up to the voltage, though.

--
*Arkansas State Motto: Don't Ask, Don't Tell, Don't Laugh.

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

"David Hearn" wrote in message
...
snip
I agree that in most case, you'll probably find that a standard
crimp
doesn't cover the oxidation issue - but I don't believe many other
common fixings (other than soldering) make much, if any, attempt at
doing his either. At least with crimps you have a better mechanical
joint than screws, practically all the external surface of the wire
is
in contact with the crimp - and I'd doubt the electrical joint was
significantly worse than a screw terminal. Based on that, a crimp
joint
seems better, or am I missing anything?

D

I was taught that a properly made crimp is actually a gas tight joint
at the points of contact, so if the wires were acceptably free of
oxide when crimped, they should remain so.(This is apparently true
also of a 'wire wrapped' joint previously used in telecoms and early
computers, where a wire is tightly wrapped round a square post to make
a connection.) Crimps used in low voltage applications where high
humidity is expected (external joint boxes for telephones for
instance) are filled with a vaseline like anti-oxidant water
repellant.

AWEM

In article ,
Tony Williams writes:
Bare copper is a reactive metal, subject to long term
oxidation, or verdigris, or other chemical attack.
To make a reliable crimp joint onto bare copper needs
something that first of all cuts through any oxidation
that may be there, and then makes a gas-tight connection.

Copper Oxide (unlike Aluminium Oxide) is a conductor though.
So providing there's only a thin layer and the copper is still
reasonably copper coloured and not dark red or black, there's
normally no problem. The deformation of the surface of the
copper in any type of terminal will break through it anyway
(again, unlike Aluminium Oxide which is extremely hard).

--
Andrew Gabriel

On Tue, 14 Jun 2005 09:55:40 +0100, David Hearn
wrote:

How then are screw terminals acceptable?

A screw point is not terribly big, so I wouldn't expect it to remove a
significant amount of oxidation when screwed up

It's because they're not very big. Small area leads to a high pressure
and good gas-tight joints. However this also means poor mechanical
strength. A screw terminal with a separate slipper pad under the screw
terminal gives a better mechanical connection, but the pressure is low
and they're not gas tight. Take your pick.

--
Cats have nine lives, which is why they rarely post to Usenet.

antgel wrote:
Pete C wrote:

On Mon, 13 Jun 2005 10:02:48 +0100, "Andy Luckman (AJL Electronics)"
wrote:



In my house, the previous occupant has done all sorts of terrible things with the electrics, the shower (9.5kW) fed with 2.5mm to name just one!

The lates bodge found was behind a wall cabinet. At one time, there used to
be a double mains socket, which has been removed complete with back box and
replaced with a standard round junction box. The hole has been gouged out to
allow it to be sunk. From this, a short spur to a new, lower position.

My requirement is to open the ring at this point and run another couple or
three of sockets. I know that crimps are the way to go, but tell me this:

1) Are these crimps the same blue ones as I use for auto electrical work?


I'd consider using those on solid core to be a bodge, however they're
crimped.

I'd only use ones specifically designed for solid core and crimped in
the recommended way.


Ok. I've read enough of this thread to feel nervous. I have crimped
some 1.5T&E with some blue crimps and a ratchet crimping tool. If these
crimps are not correct for the job, can someone point me to some that
are? I have never heard of mains-rated crimps.

Antony

Aren't blue crimps meant to be used on 2.5mm T&E. For 1.5mm T&E you're
meant to use red crimps.

http://www.tlc-direct.co.uk/Main_Ind...ols/index.html

D

Andy Dingley wrote:
On Tue, 14 Jun 2005 09:55:40 +0100, David Hearn
wrote:


How then are screw terminals acceptable?


A screw point is not terribly big, so I wouldn't expect it to remove a
significant amount of oxidation when screwed up


It's because they're not very big. Small area leads to a high pressure
and good gas-tight joints. However this also means poor mechanical
strength. A screw terminal with a separate slipper pad under the screw
terminal gives a better mechanical connection, but the pressure is low
and they're not gas tight. Take your pick.


But whilst a small area will increase the pressure of the joint and
improve the gas-tightness of it - it also means that the area of contact
(and therefore electrical conduction) is smaller meaning it heats up.

I guess a lot of this is theoretical and academic. If it works in
practice then its fine - which I guess they all do, else people wouldn't
be allowed to use them.

D

In article , Stefek Zaba
wrote:

This extending-for-new-sockets topic came up a couple of weeks ago. One
of the nicest solutions was to use a dual box, to mount two singles side
by side, each with one of the old ring cables and a leg of the new bit
of ring. No chocbloc, room to breathe, and general Goodness all round...

That would be a jolly wonderful idea. Depends on the clearance to the back
of the cupboard though.

--
AJL Electronics (G6FGO) Ltd : Satellite and TV aerial systems
http://www.classicmicrocars.co.uk : http://www.ajlelectronics.co.uk

In article , John_ZIZinvalid
wrote:

Yes. Keep within the ring where possible, and don't cross connect
between both legs, this is better explained in the IEE On-Site guide
with the aid of diagrams.


Yes, that's fully understood, to keep the ring intact. I was going to
parallel the earths though. I suppose not any good reason to, as long as one
of them connects to the back box.

I don't have a copy of the IEE Regs here with me, so cannot state the
exact IEE regulation rule, but there is a rule which states the amount
of spurs you can have on ring, and that spured sockets should not
exceed the amount of sockets which make up the ring.

There will be no spurs. The whole point of doing it this way is to preserve
the ring. If there was any sensible route, I would have taken it back to the
CU, but this will be the next best option.

Your solution of using two single sockets side by side is a good way
of solving the problem, rather than using connectors and one
double/single socket.

With the cost being similar, it seems a nice idea. I'm sure that some use
could be found for the spare sockets once fitted. Just thought. I bet the
tails will be too short to reach the right hand socket. :-(

--
AJL Electronics (G6FGO) Ltd : Satellite and TV aerial systems
http://www.classicmicrocars.co.uk : http://www.ajlelectronics.co.uk