Had an electrician do a periodic inspection on my place today - I 
was very impressed by his thoroughness and knowledge. Got pulled on 
a number of points so will have to cough up for a re-inspection as I 
want to sell with a clean report:

1. No earth at bedroom light - traced to a broken connection

2. He didn't like me feeding the bathroom lights/shaver/fan through 
a fused spur unit: running 6 x 1mm cables into the outlet terminal, 
although they fit, is apparently not on. So a little rearrange 
called for.

3. Heating/hot & cold pipes need to be cross bonded even though it's 
all copper.

4. Didn't like wiring to boiler: I've got a FSU which isolates all 
the heating, a three core and a two core flex coming through the 
flex outlet (they fit tidily IMO), one feed in, the other back to 
the MVs. Needs to be replaced by a four core flex. 

5. In the new CU the earth and neutral connections must go to the 
same numbered terminals as the MCBs - I filled from one end.

The rest of you would never do any of the above of course, but just 
in case you were tempted, this may save you trouble.

-- 
Tony Bryer SDA UK  'Software to build on'  http://www.sda.co.uk

In article ,
	Tony Bryer  writes:
> 5. In the new CU the earth and neutral connections must go to the 
> same numbered terminals as the MCBs - I filled from one end.

I agree, except for a ring circuit, I always connect the two
ends of the earth to different terminals. It increases the
redundancy of the earthing, and it used to be a requirement
in the case of high earth leakage circuits in older versions
of the regs.

-- 
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Andrew Gabriel wrote:
> In article ,
> 	Tony Bryer  writes:
>> 5. In the new CU the earth and neutral connections must go to the 
>> same numbered terminals as the MCBs - I filled from one end.
> 
> I agree,

Yes, although I think Tony's inspector was being a wee bit anal on some 
of the points.  The requirement is only that the conductors can be 
identified for testing, repair or alteration [514.1.2] and (IMHO) 
connecting the neutrals and CPCs in the same running order as the MCBs 
is OK.  In any case the neutrals in a split-load board have to go to the 
right group and it's not always possible to use "same numbers".  For 
complicated distribution boards it's good practice to keep documentation 
and circuits can easily be mapped to terminal numbers in the schedule of 
circuits.

> except for a ring circuit, I always connect the two ends of the earth
> to different terminals. It increases the redundancy of the earthing,
> and it used to be a requirement in the case of high earth leakage
> circuits in older versions of the regs.

It still is one of the options in the 17th ed. (used along with separate 
termination of each CPC at each accessory).  I don't recall much 
changing in the high-integrity earthing section since it was first 
introduced, except that "high earth leakage" was changed to "high 
protective conductor current" to clarify that it doesn't apply where the 
leakage doesn't flow via the CPC.  In the new edition this has moved to 
the main body of the regs [543.7] and is no longer a separate section.

-- 
Andy

In article , Andy Wade <spambucket@m
axwell.myzen.co.uk> scribeth thus
>Andrew Gabriel wrote:
>> In article ,
>>      Tony Bryer  writes:
>>> 5. In the new CU the earth and neutral connections must go to the 
>>> same numbered terminals as the MCBs - I filled from one end.
>> 
>> I agree,
>
>Yes, although I think Tony's inspector was being a wee bit anal on some 
>of the points. 

Arse protecting;?....... 

-- 
Tony Sayer

Tony Bryer wrote:

I'm wondering what Code numbers were given, and regulations cited, if any:

> 1. No earth at bedroom light

Code 1  (or Code 2 for a class 2 fitting)?

> 2. He didn't like me feeding the bathroom lights/shaver/fan through 
> a fused spur unit: running 6 x 1mm cables into the outlet terminal,

Regulation number?  Code 2 or 4?

> 3. Heating/hot & cold pipes need to be cross bonded even though it's 
> all copper.

In bathroom, presumably - Code 2?

> 4. Didn't like wiring to boiler: I've got a FSU which isolates all 
> the heating, a three core and a two core flex coming through the 
> flex outlet (they fit tidily IMO), one feed in, the other back to 
> the MVs. Needs to be replaced by a four core flex.

Regulation number?  Code 2 or 4?

> 5. In the new CU the earth and neutral connections must go to the 
> same numbered terminals as the MCBs - I filled from one end.

Code 2 or 4?

You might want to read
http://www.esc.org.uk/pdfs//business-and-community/electrical-industry/BPG3_08.pdf 

which gives advice on coding, with examples.

-- 
Andy

tony sayer wrote:

> Arse protecting;?....... 

That's what PI insurance is for.

-- 
Andy

On Sun, 29 Jun 2008 09:57:34 +0100, tony sayer wrote:

> In article , Andy Wade <spambucket@m
> axwell.myzen.co.uk> scribeth thus
>>Andrew Gabriel wrote:
>>> In article ,
>>>      Tony Bryer  writes:
>>>> 5. In the new CU the earth and neutral connections must go to the
>>>> same numbered terminals as the MCBs - I filled from one end.
>>> 
>>> I agree,
>>
>>Yes, although I think Tony's inspector was being a wee bit anal on some
>>of the points.
> 
> Arse protecting;?.......

Let's face it, choosing to be an inspector is bound to imply a degree of 
obsessive compulsiveness - much like programming appeals to people with 
mild Aspergers...

On Sun, 29 Jun 2008 10:59:57 GMT PCPaul wrote :
> > 
> > Arse protecting;?.......
> 
> Let's face it, choosing to be an inspector is bound to imply a degree of 
> obsessive compulsiveness - much like programming appeals to people with 
> mild Aspergers...

I was quite happy with his approach, likewise he could see that if a few 
details were lacking/not was he would have done it, all the key stuff was 
right - bonds to incoming services, sleeving at accessories, ring 
continuity etc etc. Also I made it clear to him that I wanted to sell on 
knowing that everything was genuinely AOK, rather than just wanting a bit 
of paper issued by someone who would sign anything. 

-- 
Tony Bryer SDA UK  'Software to build on'  http://www.sda.co.uk

On 29 Jun,  
     Andy Wade  wrote:

> 
> You might want to read
> http://www.esc.org.uk/pdfs//business-and-community/electrical-industry/BPG3_08.pdf 
> 
> which gives advice on coding, with examples.
> 
>
Shirley
<http://www.esc.org.uk/pdfs//business-and-community/electrical-industry/BPG4_08.pdf>
Would be more appropriate.


-- 
  B Thumbs
  Change lycos to yahoo to reply

tony sayer wrote:
> In article , Andy Wade <spambucket@m
> axwell.myzen.co.uk> scribeth thus
>> Andrew Gabriel wrote:
>>> In article ,
>>>      Tony Bryer  writes:
>>>> 5. In the new CU the earth and neutral connections must go to the 
>>>> same numbered terminals as the MCBs - I filled from one end.
>>> I agree,
>> Yes, although I think Tony's inspector was being a wee bit anal on some 
>> of the points. 
> 
> Arse protecting;?....... 

Probably just a need to find something to make you feel you got your 
money's worth!

-- 
Cheers,

John.

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

me9@privacy.net wrote:

> Shirley
> <http://www.esc.org.uk/pdfs//business-and-community/electrical-industry/BPG4_08.pdf>
> Would be more appropriate.

It certainly would.  I copied the wrong URL, sorry.

-- 
Andy

"Andy Wade"  wrote in message 
news:6crlkhF3io1ptU1@mid.individual.net...
> me9@privacy.net wrote:
>
>> Shirley
>> <http://www.esc.org.uk/pdfs//business-and-community/electrical-industry/BPG4_08.pdf>
>> Would be more appropriate.
>
> It certainly would.  I copied the wrong URL, sorry.
>
> -- 
> Andy

The photo on page 6 shows the inspector using a neon screwdriver. I hope he 
only used it to remove the front plate :-)

Adam

On 2008-06-30 18:52:04 +0100, "ARWadworth" 
 said:

> 
> "Andy Wade"  wrote in message 
> news:6crlkhF3io1ptU1@mid.individual.net...
>> me9@privacy.net wrote:
>> 
>>> Shirley
>>> <http://www.esc.org.uk/pdfs//business-and-community/electrical-industry/BPG4_08.pdf>
Would 
>>> 
>>> be more appropriate.
>> 
>> It certainly would.  I copied the wrong URL, sorry.
>> 
>> -- 
>> Andy
> 
> The photo on page 6 shows the inspector using a neon screwdriver. I 
> hope he only used it to remove the front plate :-)
> 
> Adam 

He can't be an inspector.  He hasn't got a peaked cap.

I thought that the photovoltaic system listed on page 12 was a cracker 
- listed under Requires Improvement.  :-)

"Andy Hall" <andyh@hall.nospam> wrote in message news:486922d8@qaanaaq...
> On 2008-06-30 18:52:04 +0100, "ARWadworth" 
>  said:
>
>>
>> "Andy Wade"  wrote in message 
>> news:6crlkhF3io1ptU1@mid.individual.net...
>>> me9@privacy.net wrote:
>>>
>>>> Shirley
>>>> <http://www.esc.org.uk/pdfs//business-and-community/electrical-industry/BPG4_08.pdf>
> Would
>>>>
>>>> be more appropriate.
>>>
>>> It certainly would.  I copied the wrong URL, sorry.
>>>
>>> -- 
>>> Andy
>>
>> The photo on page 6 shows the inspector using a neon screwdriver. I hope 
>> he only used it to remove the front plate :-)
>>
>> Adam
>
> He can't be an inspector.  He hasn't got a peaked cap.
>
> I thought that the photovoltaic system listed on page 12 was a cracker - 
> listed under Requires Improvement.  :-)

The photo on page 13 of a typical RCD split load CU has been labelled my a 
pissed up man (or woman). The stickers are all to cock and on a MK CU (as 
with many other manufacturers) it  should be green headers carrying on to 
the right after the RCD PROTECTED CIRCUITS sticker not red. The correct 
stickers came in the box.

We will have fun with this link at work tommorrow.

Adam

ARWadworth wrote:

> The photo on page 13 of a typical RCD split load CU has been labelled my 
> a pissed up man (or woman). The stickers are all to cock and on a MK CU 
> (as with many other manufacturers) it  should be green headers carrying 
> on to the right after the RCD PROTECTED CIRCUITS sticker not red. The 
> correct stickers came in the box.

Yes I noticed that, but then the caption does say "in typical split load 
etc."  It wouldn't surprise me at all if that's typical of what's found 
in the field.  Not many years ago finding _any_ labelling was a rarity...

-- 
Andy

On Tue, 01 Jul 2008 01:05:46 +0100, Andy Wade wrote:

> ARWadworth wrote:
> 
>> The photo on page 13 of a typical RCD split load CU has been labelled
>> my a pissed up man (or woman). The stickers are all to cock and on a MK
>> CU (as with many other manufacturers) it  should be green headers
>> carrying on to the right after the RCD PROTECTED CIRCUITS sticker not
>> red. The correct stickers came in the box.
> 
> Yes I noticed that, but then the caption does say "in typical split load
> etc."  It wouldn't surprise me at all if that's typical of what's found
> in the field.  Not many years ago finding _any_ labelling was a
> rarity...

You thought you had done OK if found "lights" in pencil on the dark 
bakerlite cover of a Wylex 6 way CU. 


-- 
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk 
Gas fitting FAQ  http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html

In article ,
   Andy Wade  wrote:
> Yes I noticed that, but then the caption does say "in typical split load 
> etc."  It wouldn't surprise me at all if that's typical of what's found 
> in the field.  Not many years ago finding _any_ labelling was a rarity...

I scanned the label for my new CU, did all the circuit naming in a
matching font, coloured cross hatching for RCD protected and printed it
out on sticky backed paper. Anorak? Never in a million years.

-- 
*Learn from your parents' mistakes - use birth control

    Dave Plowman        dave@davenoise.co.uk           London SW
                  To e-mail, change noise into sound.

Dave Plowman (News) wrote:

> I scanned the label for my new CU, did all the circuit naming in a
> matching font, coloured cross hatching for RCD protected and printed it
> out on sticky backed paper.

I've done similar.  The house CU label here was drawn in autoCAD and 
produced on a pen plotter.  Remember pen plotters...?

> Anorak? Never in a million years. 

Of course not.

-- 
Andy

Ed Sirett wrote:
> 
> You thought you had done OK if found "lights" in pencil on the dark 
> bakerlite cover of a Wylex 6 way CU.

That's about it, yes.  I think some of the perpetrators have gone on to 
become web site designers :~)

-- 
Andy

On Tue, 1 Jul 2008 22:06:09 UTC, "Dave Plowman (News)" 
 wrote:

> In article ,
>    Andy Wade  wrote:
> > Yes I noticed that, but then the caption does say "in typical split load 
> > etc."  It wouldn't surprise me at all if that's typical of what's found 
> > in the field.  Not many years ago finding _any_ labelling was a rarity...
> 
> I scanned the label for my new CU, did all the circuit naming in a
> matching font, coloured cross hatching for RCD protected and printed it
> out on sticky backed paper. Anorak? Never in a million years.

Last time I did something like that, I printed on plain paper, laminated
each label and then attached them with superglue!

-- 
The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
   http://www.diybanter.com

Ed Sirett wrote:
>> Not many years ago finding _any_ labelling was a
>> rarity...
> You thought you had done OK if found "lights" in pencil on the dark 
> bakerlite cover of a Wylex 6 way CU. 

6 way, eh.

My parents had (still have) a 4-way, with the ways labelled (be me, in 
dymo tape)

1. Cooker (30A)
2. Sockets (30A)
3. Immersion, and Socket in Bedroom, and CH, and Socket in Garage, and 
Socket in Lounge. (15A)
4. Lights (5A)

I found out that "socket in Lounge" was on fuse 3 not 2 "the hard way"!

Owain

Andy Wade wrote:
> Dave Plowman (News) wrote:
> 
>> I scanned the label for my new CU, did all the circuit naming in a
>> matching font, coloured cross hatching for RCD protected and printed it
>> out on sticky backed paper.
> 
> I've done similar.  The house CU label here was drawn in autoCAD and 
> produced on a pen plotter.  Remember pen plotters...?

With some regret, I lobbed my[1] HP7475 in a skip a few months back 
after having had it sat in a cupboard unused for getting on for 15 years....

[1] Bought at auction with three others for £65 a piece IIRC



-- 
Cheers,

John.

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

On Wed, 02 Jul 2008 04:27:06 +0100, John Rumm wrote:

> Andy Wade wrote:
>> Dave Plowman (News) wrote:
>> 
>>> I scanned the label for my new CU, did all the circuit naming in a
>>> matching font, coloured cross hatching for RCD protected and printed
>>> it out on sticky backed paper.
>> 
>> I've done similar.  The house CU label here was drawn in autoCAD and
>> produced on a pen plotter.  Remember pen plotters...?
> 
> With some regret, I lobbed my[1] HP7475 in a skip a few months back
> after having had it sat in a cupboard unused for getting on for 15
> years....
> 
> [1] Bought at auction with three others for £65 a piece IIRC

Aww... Im sure they would make excellent small scale CNC machines/
engravers when fitted with a dremel...

PCPaul wrote:
> On Wed, 02 Jul 2008 04:27:06 +0100, John Rumm wrote:
> 
>> Andy Wade wrote:
>>> Dave Plowman (News) wrote:
>>>
>>>> I scanned the label for my new CU, did all the circuit naming in a
>>>> matching font, coloured cross hatching for RCD protected and printed
>>>> it out on sticky backed paper.
>>> I've done similar.  The house CU label here was drawn in autoCAD and
>>> produced on a pen plotter.  Remember pen plotters...?
>> With some regret, I lobbed my[1] HP7475 in a skip a few months back
>> after having had it sat in a cupboard unused for getting on for 15
>> years....
>>
>> [1] Bought at auction with three others for £65 a piece IIRC
> 
> Aww... Im sure they would make excellent small scale CNC machines/
> engravers when fitted with a dremel...

Possibly - they had quite substantial stepper motors for the platten and 
turret axis. Not sure if the pen up/down mechanism would cope with a 
dremel without serious modification though.

(brings back memories from years ago where I managed to annoy a whole 
lab by running a DEC rebadged 7475 plotting radar flight path data from 
a spreadsheet that was part of the old DOS "Smart" package. It did not 
quite have the intelligence in the spreadsheet to work out that if you 
wanted a line from point A to B and then a line from B to C that it 
could do the next line without picking up the pen and putting it down 
again. Hence each of 8000 short lines that made up the plot would be 
drawn with a pen up and down between *every* segment. Sounded like a 
demented woodpecker hammering away non stop for a couple of hours!)


-- 
Cheers,

John.

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

On Wed, 02 Jul 2008 14:38:05 +0100, John Rumm wrote:
> 
> (brings back memories from years ago where I managed to annoy a whole
> lab by running a DEC rebadged 7475 plotting radar flight path data from
> a spreadsheet that was part of the old DOS "Smart" package. It did not
> quite have the intelligence in the spreadsheet to work out that if you
> wanted a line from point A to B and then a line from B to C that it
> could do the next line without picking up the pen and putting it down
> again. Hence each of 8000 short lines that made up the plot would be
> drawn with a pen up and down between *every* segment. Sounded like a
> demented woodpecker hammering away non stop for a couple of hours!)

I remember writing a bit of HP-IB code in BBC Basic for exactly that 
problem - it pretended to be a plotter, accepted the command stream and 
rewrote it to avoid Pen up, Pen down without a move in between. Forward 
it to the plotter and away you go..

That was a simple but extremely popular bit of code.. not as nice as the 
one that took the BBC micro 'VDU' command stream (which always used a 
virtual resolution of 1280x1024 regardless of screen mode) and sent it as 
PCL to a Laserjet - much higher resolution than the usual screendumps, 
and faster too. Also a fun project, basically building up a framebuffer 
in RAM then sending it out as a PCL compressed raster file to fill an A4 
page. I don't think I've ever had a project with such clear requirements 
since :-(

"John Rumm"  wrote in message 
news:0tGdnfh40-tfGfbVnZ2dnUVZ8h2dnZ2d@posted.plusnet...
> PCPaul wrote:
>> On Wed, 02 Jul 2008 04:27:06 +0100, John Rumm wrote:
>>
>>> Andy Wade wrote:
>>>> Dave Plowman (News) wrote:
>>>>
>>>>> I scanned the label for my new CU, did all the circuit naming in a
>>>>> matching font, coloured cross hatching for RCD protected and printed
>>>>> it out on sticky backed paper.
>>>> I've done similar.  The house CU label here was drawn in autoCAD and
>>>> produced on a pen plotter.  Remember pen plotters...?
>>> With some regret, I lobbed my[1] HP7475 in a skip a few months back
>>> after having had it sat in a cupboard unused for getting on for 15
>>> years....
>>>
>>> [1] Bought at auction with three others for £65 a piece IIRC
>>
>> Aww... Im sure they would make excellent small scale CNC machines/
>> engravers when fitted with a dremel...
>
> Possibly - they had quite substantial stepper motors for the platten and 
> turret axis. Not sure if the pen up/down mechanism would cope with a 
> dremel without serious modification though.
>
>

Betcha it would cope with a flexi-drive attachment though!

http://www.amazon.co.uk/Rotacraft-Rotary-hanging-stand-accessories/dp/B000B8JNYK


-- 
Keith

 

** Posted from http://www.teranews.com **

"Owain"  wrote in message 
news:POudnbFQqoF9WPfVRVnyhwA@posted.plusnet...
> Ed Sirett wrote:
>>> Not many years ago finding _any_ labelling was a
>>> rarity...
>> You thought you had done OK if found "lights" in pencil on the dark 
>> bakerlite cover of a Wylex 6 way CU.
>
> 6 way, eh.
>
> My parents had (still have) a 4-way, with the ways labelled (be me, in 
> dymo tape)

4 way, you were spoilt as a child.

It was a lot worse in Yorkshire. I had a 2 way when I was a child.

http://www.youtube.com/watch?v=Xe1a1wHxTyo

Adam

On 2008-07-02 19:07:39 +0100, "ARWadworth" 
 said:

> 
> "Owain"  wrote in message 
> news:POudnbFQqoF9WPfVRVnyhwA@posted.plusnet...
>> Ed Sirett wrote:
>>>> Not many years ago finding _any_ labelling was a
>>>> rarity...
>>> You thought you had done OK if found "lights" in pencil on the dark 
>>> bakerlite cover of a Wylex 6 way CU.
>> 
>> 6 way, eh.
>> 
>> My parents had (still have) a 4-way, with the ways labelled (be me, in 
>> dymo tape)
> 
> 4 way, you were spoilt as a child.
> 
> It was a lot worse in Yorkshire. I had a 2 way when I was a child.
> 
> http://www.youtube.com/watch?v=Xe1a1wHxTyo
> 
> Adam

Looksheree.....

On Wed, 02 Jul 2008 20:14:49 +0300, Keith wrote:

> "John Rumm"  wrote in message
> news:0tGdnfh40-tfGfbVnZ2dnUVZ8h2dnZ2d@posted.plusnet...
>> PCPaul wrote:
>>> On Wed, 02 Jul 2008 04:27:06 +0100, John Rumm wrote:
>>>
>>>> Andy Wade wrote:
>>>>> Dave Plowman (News) wrote:
>>>>>
>>>>>> I scanned the label for my new CU, did all the circuit naming in a
>>>>>> matching font, coloured cross hatching for RCD protected and
>>>>>> printed it out on sticky backed paper.
>>>>> I've done similar.  The house CU label here was drawn in autoCAD and
>>>>> produced on a pen plotter.  Remember pen plotters...?
>>>> With some regret, I lobbed my[1] HP7475 in a skip a few months back
>>>> after having had it sat in a cupboard unused for getting on for 15
>>>> years....
>>>>
>>>> [1] Bought at auction with three others for £65 a piece IIRC
>>>
>>> Aww... Im sure they would make excellent small scale CNC machines/
>>> engravers when fitted with a dremel...
>>
>> Possibly - they had quite substantial stepper motors for the platten
>> and turret axis. Not sure if the pen up/down mechanism would cope with
>> a dremel without serious modification though.
>>
>>
>>
> Betcha it would cope with a flexi-drive attachment though!
> 
> http://www.amazon.co.uk/Rotacraft-Rotary-hanging-stand-accessories/dp/
B000B8JNYK

That's mopre like what I was thinking about.

Or a cutter head so you can do your own signwriting...

The message <LtPak.19606$E41.3390@text.news.virginmedia.com>
from "ARWadworth"  contains these words:

> > My parents had (still have) a 4-way, with the ways labelled (be me, in 
> > dymo tape)

> 4 way, you were spoilt as a child.

> It was a lot worse in Yorkshire. I had a 2 way when I was a child.

> http://www.youtube.com/watch?v=Xe1a1wHxTyo

Not exactly back to my childhood but when I moved to my present hovel
(in Yorkshire as it happens) 30 years ago there was only a 3 way fuse
box. One ring circuit, one cooker point and the lights.

Some time later I found that the visible earth wire from the fuse box
actually terminated on a rusty nail loosely pushed into a joint in the
wall behind a cupboard. Being rather worried by this I bought a pukka
earth rod and banged that through the kitchen floor as a replacement for
the rusty nail.

Some further time later I found that there was also an earth wire link
back to the company fuse block but I have never got round to
disconnecting the earth road although from time to time I wonder whether
it is doing any good at all. Should I disconnect the earth rod?

-- 
Roger Chapman

Roger wrote:

> [...]
> Some further time later I found that there was also an earth wire link
> back to the company fuse block but I have never got round to
> disconnecting the earth road although from time to time I wonder whether
> it is doing any good at all. Should I disconnect the earth rod?

You may as well leave it alone.  It won't do any harm and it might do a 
tiny little bit of good.

-- 
Andy

The message 
from Andy Wade  contains these words:

> > Some further time later I found that there was also an earth wire link
> > back to the company fuse block but I have never got round to
> > disconnecting the earth road although from time to time I wonder whether
> > it is doing any good at all. Should I disconnect the earth rod?

> You may as well leave it alone.  It won't do any harm and it might do a 
> tiny little bit of good.

It can stay then at least until I decide to put some insulation and
screed on top of the existing floor. Even then it could stay but it
would look a bit odd with the insulated earth wire disappearing into the
concrete. I don't suppose for a moment I would be able to pull it up by
4" so the clamp stays above the surface.

-- 
Roger Chapman