I've just fitted some new sockets in a bedroom. The cable was just a little
too short to reach the socket, so I had to extend it using a few terminal
blocks (chocolate block) and some spare cable.

Trouble is, I used a 15 amp terminator block. I've got a couple of
questions:

- I seem to recall that 30 amp should be used (FWIW I've no reason to think
my house is anything other than a standard ring main). But will I be OK with
15 amp?

- comparing 15 amp and 30 amp terminal blocks side by side, the 15 amp
appears to have MORE metal than the 30 amp. I guess 30amp is like that to
allow fatter cables in, but surely this means I'll be OK with a 15amp?

- In another bedroom, I had to chisel out the ring main cable from a
concrete wall. This involved accidentally baring the cable in parts so I
decided to cut it off from the highest point I could and apply new cable. To
join old + new cable, I used 30 amp terminal blocks but over tightened some
so the metal cracked. The cables seemed to be fixed tight so I didn't worry.
Should I have?

"Brian" wrote in message
...
snip

- comparing 15 amp and 30 amp terminal blocks side by side, the 15
amp
appears to have MORE metal than the 30 amp. I guess 30amp is like
that to
allow fatter cables in, but surely this means I'll be OK with a
15amp?

- In another bedroom, I had to chisel out the ring main cable from a
concrete wall. This involved accidentally baring the cable in parts
so I
decided to cut it off from the highest point I could and apply new
cable. To
join old + new cable, I used 30 amp terminal blocks but over
tightened some
so the metal cracked. The cables seemed to be fixed tight so I
didn't worry.
Should I have?


This has got to be a troll, or at least I hope so.....

- In another bedroom, I had to chisel out the ring main cable from a
concrete wall. This involved accidentally baring the cable in parts so I
decided to cut it off from the highest point I could and apply new cable. To
join old + new cable, I used 30 amp terminal blocks but over tightened some
so the metal cracked. The cables seemed to be fixed tight so I didn't worry.
Should I have?

Have you reburied these in the wall ?

Dave

Brian wrote:

I've just fitted some new sockets in a bedroom. The cable

Trouble is, I used a 15 amp terminator block. I've got a

will I be OK with
15 amp?

I've never noticed them get even slightly warm at full rated, so I
would think so. If the 2 wires are both put thru full length instead of
half way you get a good copper to copper connection, making the
connector current rating less significant. But really you ought to use
a 30A conn.


join old + new cable, I used 30 amp terminal blocks but over
tightened some
so the metal cracked. The cables seemed to be fixed tight so I didn't
worry.
Should I have?

replace it then, you cant get even a half decent clamping with broken
metal. Recipe for a fry up.


NT

Brian wrote:

- In another bedroom, I had to chisel out the ring main cable from a
concrete wall. This involved accidentally baring the cable in parts so I
decided to cut it off from the highest point I could and apply new cable. To
join old + new cable, I used 30 amp terminal blocks but over tightened some
so the metal cracked. The cables seemed to be fixed tight so I didn't worry.
Should I have?

If you are going to plaster over the cable again then you need to either
solder or crimp the join and not use screw terminals. Sheath the
individual wires and the overall cable in heatshrink as well.

--
Cheers,

John.

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

- In another bedroom, I had to chisel out the ring main cable from a
concrete wall. This involved accidentally baring the cable in parts so I
decided to cut it off from the highest point I could and apply new
cable. To
join old + new cable, I used 30 amp terminal blocks but over tightened
some
so the metal cracked. The cables seemed to be fixed tight so I didn't
worry.
Should I have?

If you are going to plaster over the cable again then you need to either
solder or crimp the join and not use screw terminals. Sheath the
individual wires and the overall cable in heatshrink as well.


OK - I've decided that the terminal blocks aren't a good enough solution so
I've decided they must come out. Some were contained behind plasterboard,
which has meant a messy pain in the a*** to expose them, but I guess you
live and learn.

I'm going to go and buy a crimping kit but I don't fancy mucking around with
heatshrink wrap (I haven't got a soldering iron and the terminal blocks I'm
replacing are in awkward positions). Will good electrical tape do as good a
job?

One other question - is there any harm in my using 4mm core cable in what
may be a 2.5mm core radial system?

If you are going to plaster over the cable again then you need to either
solder or crimp the join and not use screw terminals. Sheath the
individual wires and the overall cable in heatshrink as well.



And what about this discussion, previously held on this very forum?

http://groups.google.co.uk/group/uk....c111a32fa3cee8
/8251a0bec126cf1a?q=crimping+4mm+cable+uk.d-i-y&rnum=1&hl=en#8251a0bec126cf1
a

I'll be honest, guys - I'm getting confused.

Here's the situation. I have some ring main cables coming out of a concrete
cladded wall.

For reasons of a damp proof membrane, I had to pull the cable out from the
concrete up until around 1.5 metres high.

I bared the wire in parts while doing this, so have had to replace that
patch of cable.

I now need some safe and reliable method of joining the old ring main cable
to new. I previously used terminal blocks but I don't think they're safe.
Crimping appears to be both a dark art and dangerous. Soldering sounds like
the next best option but does this simply involve a standard soldering iron
+ solder (as we use to make circuit boards)?

Help will be really appreciated here.

"Brian" wrote in message
...
- In another bedroom, I had to chisel out the ring main cable
from a
concrete wall. This involved accidentally baring the cable in
parts so I
decided to cut it off from the highest point I could and apply
new
cable. To
join old + new cable, I used 30 amp terminal blocks but over
tightened
some
so the metal cracked. The cables seemed to be fixed tight so I
didn't
worry.
Should I have?

If you are going to plaster over the cable again then you need to
either
solder or crimp the join and not use screw terminals. Sheath the
individual wires and the overall cable in heatshrink as well.


OK - I've decided that the terminal blocks aren't a good enough
solution so
I've decided they must come out. Some were contained behind
plasterboard,
which has meant a messy pain in the a*** to expose them, but I guess
you
live and learn.

I'm going to go and buy a crimping kit but I don't fancy mucking
around with
heatshrink wrap (I haven't got a soldering iron and the terminal
blocks I'm
replacing are in awkward positions). Will good electrical tape do as
good a
job?

One other question - is there any harm in my using 4mm core cable in
what
may be a 2.5mm core radial system?


Put your tools down NOW and step back, you are clueless and a danger,
employ an electrician before you burn your house down...

In article ,
Brian wrote:
Soldering sounds like the next best option but does this simply involve
a standard soldering iron + solder (as we use to make circuit boards)?

Only if it's 50 watts +. But the sheds sell 'instant' heat solder guns
which will have power aplenty quite cheaply.

--
*How many roads must a man travel down before he admits he is lost? *

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

Brian wrote:

If you are going to plaster over the cable again then you need to either
solder or crimp the join and not use screw terminals. Sheath the
individual wires and the overall cable in heatshrink as well.



And what about this discussion, previously held on this very forum?

http://groups.google.co.uk/group/uk....c111a32fa3cee8
/8251a0bec126cf1a?q=crimping+4mm+cable+uk.d-i-y&rnum=1&hl=en#8251a0bec126cf1
a

I'll be honest, guys - I'm getting confused.

Well to quote Whitfield from his guide the the regs: "All joints must be
accessible for inspection and testing unless they are buried in compound
or encapsulated, are between the cold tail and element of a heater such
as a pipe tracer or underfloor heating system, or are made by soldering,
welding, brazing, or compression."

So that limits your choices a little. Crimps remain an allowable
solution in the wiring regs, and personally I have not had any problems
with crimped connections (made with a decent ratchet crimper). That does
not mean however that problems do not occur though. I find that if you
crimp 2.5mm T&E (I use splice connectors that are long enough to let you
get in two crimps per side) you get a mechanically strong joint that can
not be pulled apart, and the metal of the crimp *does* bite into, and
compress the copper.

I now need some safe and reliable method of joining the old ring main cable
to new. I previously used terminal blocks but I don't think they're safe.
Crimping appears to be both a dark art and dangerous. Soldering sounds like
the next best option but does this simply involve a standard soldering iron
+ solder (as we use to make circuit boards)?

If you want to solder, then use a powerful iron with a big bit so you
can heat the joint quickly. Twist the wires together first, tin the bit
of the iron, apply to joint, flow solder into joint, remove solder,
remove iron. Should take about 3 secs per wire. Each wire needs to be
individualy sheathed, and again there needs to be an overall sheath or
container of some sort.



--
Cheers,

John.

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

Brian wrote:

OK - I've decided that the terminal blocks aren't a good enough solution so
I've decided they must come out. Some were contained behind plasterboard,
which has meant a messy pain in the a*** to expose them, but I guess you
live and learn.

I'm going to go and buy a crimping kit but I don't fancy mucking around with
heatshrink wrap (I haven't got a soldering iron and the terminal blocks I'm
replacing are in awkward positions). Will good electrical tape do as good a
job?

I find heatshrink is quicker and easier than tape, a very small
precision blowtorch works very well for shrinking it ;-)

(Not sure on what the official line is on using tape, I have in the past
used it (as I expect has everyone else ;-), but I have never really
liked it!)

One other question - is there any harm in my using 4mm core cable in what
may be a 2.5mm core radial system?

No electrical or regs problem using an overrated cable, however a future
maintainer may make an assumption that the whole circuit is in 4mm sq
and up the fuse/mcb to 30A which won't be good for the 2.5mm sections.
You may also find that 4mm sq is harder to work with in the confines of
back boxes etc.

--
Cheers,

John.

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

In article ,
Brian wrote:
I'm going to go and buy a crimping kit but I don't fancy mucking around
with heatshrink wrap

You can use an ordinary hot air gun for shrinking it with some care.
Preferably a two heat one on low. Even an ordinary hair drier.

--
*Why do overlook and oversee mean opposite things?

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

I now need some safe and reliable method of joining the old ring main cable
to new. I previously used terminal blocks but I don't think they're safe.
Crimping appears to be both a dark art and dangerous. Soldering sounds like
the next best option but does this simply involve a standard soldering iron
+ solder (as we use to make circuit boards)?

Help will be really appreciated here.

The really important point with soldering is the joint must be physically
strong before you solder. DON'T rely on solder to provide both strength
and conductivity, it wont !!.

Dave

Brian wrote:
I've just fitted some new sockets in a bedroom. The cable was just a
little
too short to reach the socket, so I had to extend it using a few
terminal
blocks (chocolate block) and some spare cable.

Trouble is, I used a 15 amp terminator block. I've got a couple of
questions:

- I seem to recall that 30 amp should be used (FWIW I've no reason to
think
my house is anything other than a standard ring main). But will I be
OK with
15 amp?

- comparing 15 amp and 30 amp terminal blocks side by side, the 15
amp
appears to have MORE metal than the 30 amp. I guess 30amp is like
that to
allow fatter cables in, but surely this means I'll be OK with a
15amp?

- In another bedroom, I had to chisel out the ring main cable from a
concrete wall. This involved accidentally baring the cable in parts
so I
decided to cut it off from the highest point I could and apply new
cable. To
join old + new cable, I used 30 amp terminal blocks but over
tightened some
so the metal cracked. The cables seemed to be fixed tight so I didn't
worry.
Should I have?

replace the broken connctor, wrap them in insulting tape, end of
problem. The rest is, well, making work for the sake of it. Put wires
full length into the conns and each one is gripped by 2 screws, very
secure.


NT

The really important point with soldering is the joint must be physically
strong before you solder. DON'T rely on solder to provide both strength
and conductivity, it wont !!.

I've just finished soldering the joints and the power is now back on (hence
my computer being up and running...)

Here's what I did. Please don't say this was wrong (this is 2.5mm core by
the way):

1) Stripped around 1in of wire on each cable
2) Twisted them together using pliers (the best I could - often it was the
case that one wire was tightly coiled around the other)
3) Soldered them so that the solder "flowed" into the joints between the
cables (visually, this was not unlike what happens when welding pipes using
presoldered joints)

To be honest, the concept of soldering cables like this strikes me as odd.
Despite my best intentions (and those of anybody attempting this job), there
are places where the solder will be providing the conductivity. I simply
can't guarantee that copper touches copper all the way through.

Brian wrote:


I'll be honest, guys - I'm getting confused.

Here's the situation. I have some ring main cables coming out of a concrete
cladded wall.

[ ... ]

I bared the wire in parts while doing this, so have had to replace that
patch of cable.

I now need some safe and reliable method of joining the old ring main cable
to new.

The best answer is to replace the whole of the run of cable which is
najjered with new stuff. It's a ring main, and Therefore each individual
run of cable's usually pretty short - from one socket to the next.
Really, truly, the 'do it once, do it right, then forget about it for
30+ years' approach is to work out where the cable you najjered runs
from, and replace the run with a new bit.

Another sensible, useful, and compliant approach is to find a place for
a new socket - it's a rare room that wouldn't benefit from a new one.
Put said socket on the non-najjered bit of cable, i.e. 'upstream' of the
bit you did Bad Things to; run a new run from there to the Ould destination.

Either way's better than putting an unexpected, uninspectable joint
somewhere in the deep middle of nowhere - it's even more confusing to
future inhabitants if the sheath colour or guage of cable changes in
mid-run.

Doing something else won't kill you or burn your house down unless
you're truly and massively cackhanded and terminally stupid, but the
pleasure of d-i-y is being able to do a *proper* job with *better*
workmanship than a pro who's trading off quality against time-to-finish.

Stefek

Here's the situation. I have some ring main cables coming out of a
concrete
cladded wall.

[ ... ]

I bared the wire in parts while doing this, so have had to replace that
patch of cable.

I now need some safe and reliable method of joining the old ring main
cable
to new.

The best answer is to replace the whole of the run of cable which is
najjered with new stuff. It's a ring main, and Therefore each individual
run of cable's usually pretty short - from one socket to the next.
Really, truly, the 'do it once, do it right, then forget about it for
30+ years' approach is to work out where the cable you najjered runs
from, and replace the run with a new bit.

I entirely agree and I would run new cable if I could. But you missed one
point above - the wires are coming out of a concrete wall. I've no idea
where they've come from. They might have come from the room next door or
they might have come from upstairs. I haven't got a wiring diagram for this
house. I don't even know if it's a radial or ring man system (the cables
throughout appear to be 2.5mm so I'd guess the former).

This really is a situation where joining cables is the only sensible
solution, short of rewriting the entire house.

Brian wrote:


Help will be really appreciated here.



Whilst agreeing with all the solder/crimp responses nobody seems to have
suggested the accessable option. Put a standsrd socket box into the
wall at the join, then add either a socket or chocolate block and a
blank cover.

Doesn't have the aesthetics but is simple to install (assuming you can
cut the wall for the box!)

Mike

mike wrote:

Whilst agreeing with all the solder/crimp responses nobody seems to have
suggested the accessable option. Put a standsrd socket box into the
wall at the join, then add either a socket or chocolate block and a
blank cover.

Did so! ;-)

Stefek Zaba wrote:
Did so! ;-)

Yeah, Sorry,
Didnt spot your one 'till after I had posted.

Mike