Locating discontiniuty in CPC - how? Help?!
Lobster
unit, for the old circuit-breaker job (see my previous thread about the
selection of the aformentioned CU!)
Unfortunately, having removed the old CU, when I ran some tests on the
existing ring main I found that although there was continuity between L
and N on the two legs of the ring main, the two CPCs showed open circuit.
Shit.
I've been trying to track down the discontinuity for most of the day
without success. I've opened up every socket and junction box that I'm
aware of, and all connections are fine, so the only possibilities I can
come up with are (a) a damaged cable, or (b) a loose connection in a
junction box etc that I don't know about.
Unfortunately the ring main serves the entire (two storey) house, so
there's a lot of area to check. (Not ideal, but not planning on
upgrading the electrics at the moment, except I've just wired a socket
to a blank way in the new CU, so that's currently the only one in the
house! which is unoccupied BTW).
I'd really welcome advice on how best to track down the fault. What's
the best way forward - I was thinking of removing all the plug sockets,
trying to work out the route the cable takes between them, and then by
temporarily shorting the conductors and CPC at one socket position, then
check continuity at the next socket position, and try to work out which
'leg' has the problem. Does that sound about right, or is there a better
way?
Thanks
David
A.Lee
> I'd really welcome advice on how best to track down the fault. What's
> the best way forward - I was thinking of removing all the plug sockets,
> trying to work out the route the cable takes between them, and then by
> temporarily shorting the conductors and CPC at one socket position, then
> check continuity at the next socket position, and try to work out which
> 'leg' has the problem. Does that sound about right, or is there a better
> way?
You need an accurate meter.
In the OSG, there is a table of expected resistance values per metre for
a variety of cables . It can be worked out, just about, how many metres
from the CU that a fault is, if you do a little bit of testing. This
will not trace the fault, but if it is at, say, 5 metres, it would be
far easier to trace if the ring was 50 metres long.
You can take readings from each socket with a long roving lead. The one
that shows a far different ohm reading from the next nearest one has
probably got a fault between it and the next one in the ring.
Or, join up line and earth at the cu, then measure at each socket, and
again, any fault will show up with a far higher reading at one of the
sockets - or it will go gradually higher, then drop down suddenly.
Alan.
--
To reply by e-mail, change the ' + ' to 'plus'.
John MacLeod
Well, one answer if the circuits are all dead at the moment is to the
traditional "ring out" test with a bellset. However, if you have
power to the circuits, then there's no need to open up boxes to
determine what's connected to which leg. Disconnect one leg and use a
simple neon socket tester and the neon connected between live and
earth will show whether there's a connection from that particular
socket to the leg that's actually connected.
cynic
Isolate and open the ring by removing both cable ends at the consumer
unit. Short the L & CPC of one of the ring cable ends (not both) and
progressively work around each socket checking for L-CPC continuity
until you find which ones are not showing continuity and note them.
This will get you into the right area. The open circuit may not be at
the socket but at the next connection in line or damage to the cable
between. Note also there may be more than one fault so having
identified the good sockets open the connection L-CPC you made at the
consumer unit and connect the other cable end similarly. then go round
the rest of the sockets and test. Hopefully you will find all the
others bar one are "good"
You may have a hidden joint box and electricians are nothing if not
inventive in their routing.
Andrew Mawson
"Lobster" <davidlobs...@hotmail.com> wrote in message
news:_%NPo.43098$PE1...@newsfe29.ams2...
Long length of wire connected to one earth tail, and do a continuity
test to the earth of each socket working away from the consumer unit.
When continuity ceases you are in the right area. You can then do the
same using the other earth tail which hopefully will lead you to the
other side of the fault area. Somewhere between is your fault!
AWEM
Tim Watts
> So, today the plan was to swap in the sparkly new 17th edn consumer
> unit, for the old circuit-breaker job (see my previous thread about the
> selection of the aformentioned CU!)
>
> Unfortunately, having removed the old CU, when I ran some tests on the
> existing ring main I found that although there was continuity between L
> and N on the two legs of the ring main, the two CPCs showed open circuit.
>
> Shit.
>
> I've been trying to track down the discontinuity for most of the day
> without success. I've opened up every socket and junction box that I'm
> aware of, and all connections are fine, so the only possibilities I can
> come up with are (a) a damaged cable, or (b) a loose connection in a
> junction box etc that I don't know about.
Way to do this quickly is:
a) Disconnect all wires for that circuit at the CU.
b) Connect L+E of one end only.
c) Continuity test at every socket until you find the first one
continuity ceases at (hint binary chop/search pattern makes this quick
if you have any idea how the ring is run physically.
d) Your fault is now pinned down to "near this socket"
e) For a bit more finess, remove the shorting link and short L-E of the
other end of the ring.
f) You should now have the fault pinned down to being between 2
particular sockets for sure.
I know this works - I used it to locate a broken neutral.
> Unfortunately the ring main serves the entire (two storey) house, so
> there's a lot of area to check. (Not ideal, but not planning on
> upgrading the electrics at the moment, except I've just wired a socket
> to a blank way in the new CU, so that's currently the only one in the
> house! which is unoccupied BTW).
>
> I'd really welcome advice on how best to track down the fault. What's
> the best way forward - I was thinking of removing all the plug sockets,
> trying to work out the route the cable takes between them, and then by
> temporarily shorting the conductors and CPC at one socket position, then
> check continuity at the next socket position, and try to work out which
> 'leg' has the problem. Does that sound about right, or is there a better
> way?
>
> Thanks
> David
--
Tim Watts
Dave Plowman (News)
Lobster <davidlobs...@hotmail.com> wrote:
> I'd really welcome advice on how best to track down the fault. What's
> the best way forward - I was thinking of removing all the plug sockets,
> trying to work out the route the cable takes between them, and then by
> temporarily shorting the conductors and CPC at one socket position, then
> check continuity at the next socket position, and try to work out which
> 'leg' has the problem. Does that sound about right, or is there a better
> way?
It would be quicker to get a long length of wire - anything would do - and
use that to extend one of the leads to your meter. Would save a lot of
disconnecting.
I have a cable tracer device - it injects a signal at one end and a
receiver follows it along the cable. That will show where the break is
pretty accurately - assuming you can keep the receiver reasonably close to
the cable.
--
*If they arrest the Energizer Bunny, would they charge it with battery? *
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
Tim Watts
> In article<_%NPo.43098$PE1...@newsfe29.ams2>,
> Lobster<davidlobs...@hotmail.com> wrote:
>> I'd really welcome advice on how best to track down the fault. What's
>> the best way forward - I was thinking of removing all the plug sockets,
>> trying to work out the route the cable takes between them, and then by
>> temporarily shorting the conductors and CPC at one socket position, then
>> check continuity at the next socket position, and try to work out which
>> 'leg' has the problem. Does that sound about right, or is there a better
>> way?
>
> It would be quicker to get a long length of wire - anything would do - and
> use that to extend one of the leads to your meter. Would save a lot of
> disconnecting.
There's no disconnecting in my (and the other chap's) method, except for
the CU whch you'd need to do anyway.
> I have a cable tracer device - it injects a signal at one end and a
> receiver follows it along the cable. That will show where the break is
> pretty accurately - assuming you can keep the receiver reasonably close to
> the cable.
>
agreed - if you had that it would certainly help with tracing the
physical run.
--
Tim Watts
Ronald Raygun
> I'd really welcome advice on how best to track down the fault. What's
> the best way forward - I was thinking of removing all the plug sockets,
> trying to work out the route the cable takes between them, and then by
> temporarily shorting the conductors and CPC at one socket position, then
> check continuity at the next socket position, and try to work out which
> 'leg' has the problem. Does that sound about right, or is there a better
> way?
You don't need to open the sockets. As seen from the CU, you obviously
have two different ring earths. Connect one of them to ring live and the
other to ring neutral.
Then visit *every* socket in the house and test for continuity between
earth and, in turn, live and neutral. Thus you can classify each socket
as to which of the two ring earths (if any!) it is connected to.
Probably the easiest way to do this test is by using a short length of 3
core flex wired to a plug, and wrap the earth wire round one of the
buzzer's probes and hold it in place with tape, then touch the other
probe to the two remaining wires in turn.
Don't test the one socket which is still connected to the supply!
Ideally all socket earths will be connected to one or other of the earths,
although if you're unlucky you may find the odd few which are connected
to neither. By observing where the sockets change from "live earth" to
"neutral earth", you'll get a better idea where the break is.
dennis@home
"Ronald Raygun" <no....@localhost.localdomain> wrote in message
news:EURPo.34576$WJ4....@newsfe12.ams2...
Don't people make things hard..
If the power is still on..
switch it off and unplug everything.
disconnect the CPC off one leg at the CU.
power up and run around the sockets with a simple mains socket tester.
This will tell you the faulty and the working sockets.
It should be easy from there to turn the power off and buzz the cores
between the last working and the first non working socket..
Don't forget to reconnect the CPC before you put any appliances back.
If you don't have power a battery across the CPC and L/N and a 13A plug with
a bulb wired across E and L/N will do the job.
Don't leave the plug and bulb around for a kid to plug in a live socket.
![george [dicegeorge]'s profile photo](http://lh3.googleusercontent.com/a-/ALV-UjVy3egmWxdo6kgdNwXDn-6EE54MDMuR9kO5wF-DhVhewlzxjNY=s40-c)
george [dicegeorge]
This method is the best so far:
as you're using a mains tester plug
there's no danger of putting mains into a low voltage tester...
Then disconnect the other earth, reconnect the first,
do the test again,
mark the sockets with different coloured sticky tape
depending on results (4 colours?)
and make notes on a cipboard paper too,
noting which colour tape means what!
[g]
Lobster
> Lobster wrote:
>
>> I'd really welcome advice on how best to track down the fault. What's
>> the best way forward - I was thinking of removing all the plug sockets,
>> trying to work out the route the cable takes between them, and then by
>> temporarily shorting the conductors and CPC at one socket position, then
>> check continuity at the next socket position, and try to work out which
>> 'leg' has the problem. Does that sound about right, or is there a better
>> way?
>
> You don't need to open the sockets. As seen from the CU, you obviously
> have two different ring earths. Connect one of them to ring live and the
> other to ring neutral.
>
> Then visit *every* socket in the house and test for continuity between
> earth and, in turn, live and neutral. Thus you can classify each socket
> as to which of the two ring earths (if any!) it is connected to.
Thanks very much for all the replies. I used the above method which was
very straightforward - wish I'd worked that out before all the
head-scratching yesterday and not getting very far!
I was able to localise the aocket where the earth 'flipped' from ring
live to ring neutral; however it's proved a bugger to take things any
further. The two cables from the socket in question emerge under the
bathroom and various stud partitions and as far as I can tell, the
damaged leg is probably the most inaccessible in the house, buried in
plaster; snaking under the bathroom floor and finally buried under tiles
in the kitchen. I think.
Sadly I reckon I'll have to get a pro in to look at it - can't afford
any more time on this. Maybe the damaged leg will need replacing with
cable run in trunking (ugh)? But it will be a bit awkward, given the
d-i-y half-installed CU though... lead balloon time methinks?
David
m...@privacy.net
alan@darkroom.+.com (A.Lee) wrote:
> You need an accurate meter.
> In the OSG, there is a table of expected resistance values per metre for
> a variety of cables . It can be worked out, just about, how many metres
> from the CU that a fault is, if you do a little bit of testing. This
> will not trace the fault, but if it is at, say, 5 metres, it would be
> far easier to trace if the ring was 50 metres long.
>
> You can take readings from each socket with a long roving lead. The one
> that shows a far different ohm reading from the next nearest one has
> probably got a fault between it and the next one in the ring.
> Or, join up line and earth at the cu, then measure at each socket, and
> again, any fault will show up with a far higher reading at one of the
> sockets - or it will go gradually higher, then drop down suddenly.
>
I did a similar set of tests at a friend's house where all 3 conductors
showed OC. Eventually it was pinned down to between two bedroom sockets.
Floorboards up revealed the wires disappearing up the wall into the plaster
in the upstairs hall. investigating further found a back box with unstripped
cable inside, covered over by plaster, obviously overlooked at second fix. A
lack of socket on the upstairs landing has now been rectified by a new socket
outlet.
It took many hours to find the fault as several hidden junction boxes were
hidden under floors. I wonder what testing (if any) took place on the
original installation.
I have yet to convince the owner of the need for further work to remove other
departures from IEE regs as were several decades ago. I think the
installation was 13th or 14th edition, now well past its sell by date!
--
B Thumbs
Change lycos to yahoo to reply
dennis@home
"Lobster" <davidlobs...@hotmail.com> wrote in message
news:eObQo.55791$M94....@newsfe22.ams2...
> Sadly I reckon I'll have to get a pro in to look at it - can't afford any
> more time on this. Maybe the damaged leg will need replacing with cable
> run in trunking (ugh)? But it will be a bit awkward, given the d-i-y
> half-installed CU though... lead balloon time methinks?
Make into two 20A radials, it will just take a couple of breakers and a few
snips at the cable to remove the faulty bit.
Is there a lot of load to prevent this?
Lobster
Well it's a thought... however the entire house is wired with just one
ring main - this one - and converting it to two radials would (IIRC,
given the location of the fault) leave one radial with a single socket
and the rest of the installation on the other radial. So I think not...
David
ARWadsworth
Voltage drop due to the cable length would also have to be taken into
consideration.
--
Adam
Mike Barnes
Can you easily put in a new cable from the far end of the 'rest' to the
CU?
--
Mike Barnes
Ronald Raygun
> Lobster <davidlobs...@hotmail.com> wrote:
>> On 22/12/2010 07:54, dennis@home wrote:
>>> "Lobster" <davidlobs...@hotmail.com> wrote
>>>>
>>>> Sadly I reckon I'll have to get a pro in to look at it - can't
>>>> afford any more time on this. Maybe the damaged leg will need
>>>> replacing with cable run in trunking (ugh)? But it will be a bit
>>>> awkward, given the d-i-y half-installed CU though... lead balloon
>>>> time methinks?
>>>
>>> Make into two 20A radials, it will just take a couple of breakers
>>> and a few snips at the cable to remove the faulty bit.
>>> Is there a lot of load to prevent this?
>>
>> Well it's a thought... however the entire house is wired with just one
>> ring main - this one - and converting it to two radials would (IIRC,
>> given the location of the fault) leave one radial with a single socket
>> and the rest of the installation on the other radial. So I think
>> not...
>
> Voltage drop due to the cable length would also have to be taken into
> consideration.
Ah, but you're not going to get much voltage drop on the CPC, are you?
I know it's not in the spirit of the regs, but is there anything actually
in the regs to say you can't mix ring topology for live and neutral with
twin radials for the earth? So long as the earth actually gets to all
the sockets, does it really matter where it comes from and how it gets
there?
:-)
I've just had a thought. Is any of the bathroom pipework bonded to earth?
If so, is it possible that it has been spliced in to the ring, and that one
of the two connections has come adrift?
ARWadsworth
> ARWadsworth wrote:
>
>> Lobster <davidlobs...@hotmail.com> wrote:
>>> On 22/12/2010 07:54, dennis@home wrote:
>>>> "Lobster" <davidlobs...@hotmail.com> wrote
>>>>>
>>>>> Sadly I reckon I'll have to get a pro in to look at it - can't
>>>>> afford any more time on this. Maybe the damaged leg will need
>>>>> replacing with cable run in trunking (ugh)? But it will be a bit
>>>>> awkward, given the d-i-y half-installed CU though... lead balloon
>>>>> time methinks?
>>>>
>>>> Make into two 20A radials, it will just take a couple of breakers
>>>> and a few snips at the cable to remove the faulty bit.
>>>> Is there a lot of load to prevent this?
>>>
>>> Well it's a thought... however the entire house is wired with just
>>> one ring main - this one - and converting it to two radials would
>>> (IIRC, given the location of the fault) leave one radial with a
>>> single socket and the rest of the installation on the other radial.
>>> So I think not...
>>
>> Voltage drop due to the cable length would also have to be taken into
>> consideration.
>
> Ah, but you're not going to get much voltage drop on the CPC, are you?
You will if someone puts a nail into the cable.
> I know it's not in the spirit of the regs, but is there anything
> actually in the regs to say you can't mix ring topology for live and
> neutral with twin radials for the earth? So long as the earth
> actually gets to all
> the sockets, does it really matter where it comes from and how it gets
> there?
Ther are some rules, however I do believe the OP is not wanting a bodge job.
>
> I've just had a thought. Is any of the bathroom pipework bonded to
> earth? If so, is it possible that it has been spliced in to the ring,
> and that one of the two connections has come adrift?
Possible, but most unlikely.
--
Adam
Ronald Raygun
> Ronald Raygun <no....@localhost.localdomain> wrote:
>>
>> I've just had a thought. Is any of the bathroom pipework bonded to
>> earth? If so, is it possible that it has been spliced in to the ring,
>> and that one of the two connections has come adrift?
>
> Possible, but most unlikely.
So what do you think has happened here? A nail, which has managed to chop
the earth conductor and neither of the other two, and which has subsequently
been removed?
Presumably all three conductors will be taking the same physical route by
virtue of being part of the same T&E cable. Would it be worth re-connecting
the ring to the supply in order to use one of those cable detector devices
which pick up the mains "hum" even from cables buried deep in plaster?
He could then (carefully!) connect the supply live to the two ring earths
in turn, and thus (agin with said device) pinpoint the exact location where
the break is.
dennis@home
"Ronald Raygun" <no....@localhost.localdomain> wrote in message
news:jlnQo.87505$Dq6....@newsfe19.ams2...
> So what do you think has happened here? A nail, which has managed to chop
> the earth conductor and neither of the other two, and which has
> subsequently
> been removed?
A faulty bit of cable and the fault has always been there, not that that
ever happens.
ARWadsworth
> ARWadsworth wrote:
>
>> Ronald Raygun <no....@localhost.localdomain> wrote:
>>>
>>> I've just had a thought. Is any of the bathroom pipework bonded to
>>> earth? If so, is it possible that it has been spliced in to the
>>> ring, and that one of the two connections has come adrift?
>>
>> Possible, but most unlikely.
>
> So what do you think has happened here? A nail, which has managed to
> chop the earth conductor and neither of the other two, and which has
> subsequently been removed?
That is the most probable cause.
> Presumably all three conductors will be taking the same physical
> route by virtue of being part of the same T&E cable. Would it be
> worth re-connecting the ring to the supply in order to use one of
> those cable detector devices which pick up the mains "hum" even from
> cables buried deep in plaster?
>
> He could then (carefully!) connect the supply live to the two ring
> earths in turn, and thus (agin with said device) pinpoint the exact
> location where the break is.
There are proper machines for that purpose that are a bit safer than using
230V. They are not cheap though.
--
Adam
Dave Plowman (News)
ARWadsworth <adamwa...@blueyonder.co.uk> wrote:
> There are proper machines for that purpose that are a bit safer than
> using 230V. They are not cheap though.
I got one off Ebay for about 30 quid. It's really meant for tracing signal
cables - but I don't see why it wouldn't work on mains ones. Totally
disconnected, obviously.
--
*Women like silent men; they think they're listening.
Lobster
Just thought I'd report back on the outcome of this thread...
I found an electrician willing and able to come in yesterday. First
thing he looks at is my newly installed CU and with much sucking of
teeth says "well this is a bit of a mess isn't it" - he was referring to
the sequential numbers on the neutral terminals not matching up to those
on the MCBs. Oh puh-leaze...
I explained how I'd tracked down the fault to one leg of the ring with
90% certainty using Mr Reagan's above method; however he didn't
understand (or believe?) the technique and started his diagnostics from
scratch; took him two hours with his Megger to reach the same conclusion
I had. By this time I think he'd cottoned on that I wasn't a total
muppet and aided with copious quantities of tea, relations had thawed
somewhat.
In the end he decided to break into the wall at ceiling level to cut the
affected cable for further testing (it was impossible to access it above
the ceiling, which was where I'd come unstuck myself); that isolated the
problem to a break between the ceiling and the socket below. Fortunately
he was able to pull a new length of cable up through the capping, and
then connect that with a jcb above the ceiling, so just leaving me a
small hole to fill at ceiling level.
So - FYI here's the offending damage!:
http://img96.imageshack.us/img96/1548/cablecropped.jpg
Evidently caused by a picture hook or screw right into the cable.
Because I'd had the room plaster skimmed last week, there was no
evidence of this. The live wire is burned about 50% through but still
intact.
After that all testing went OK and I got my periodic insoection report
(which I was going to have done anyway, after installing the CU) without
further ado. Interestingly the one (minor) issue he raised with the
wiring was the lack of cross bonding of the CH system at the boiler;
said he trusted me to install it today and wouldn't mention it on the
report - I don't think that would have happened when he first arrived!
Thanks a lot for all the help from this ng
David
ARWadsworth
> Interestingly the one (minor) issue he raised
> with the wiring was the lack of cross bonding of the CH system at the
> boiler; said he trusted me to install it today and wouldn't mention
> it on the report - I don't think that would have happened when he
> first arrived!
I cannot see the point in cross bonding the CH at the boiler. There is no
requirement to do it.
--
Adam
Dave Plowman (News)
ARWadsworth <adamwa...@blueyonder.co.uk> wrote:
> > Interestingly the one (minor) issue he raised
> > with the wiring was the lack of cross bonding of the CH system at the
> > boiler; said he trusted me to install it today and wouldn't mention
> > it on the report - I don't think that would have happened when he
> > first arrived!
> I cannot see the point in cross bonding the CH at the boiler. There is
> no requirement to do it.
I did wonder. If that were deemed necessary, you'd have to cross bond
every rad too?
--
*Wedding dress for sale. Worn once by mistake.*
Bill
<da...@davenoise.co.uk> writes
>In article <m5oQo.95802$oI6....@newsfe05.ams2>,
> ARWadsworth <adamwa...@blueyonder.co.uk> wrote:
>> There are proper machines for that purpose that are a bit safer than
>> using 230V. They are not cheap though.
>
>I got one off Ebay for about 30 quid. It's really meant for tracing signal
>cables - but I don't see why it wouldn't work on mains ones. Totally
>disconnected, obviously.
I picked up one of these off Ebay a while back, mainly for use on
twisted pair but I have used it on mains cabling. Most useful.
<http://www.jmwlimited.co.uk/Tempo_PTS100-200_Pair_Tracing_Set.html>
>
--
Bill
ARWadsworth
> In article <x_ZQo.11188$EO....@newsfe25.ams2>,
> ARWadsworth <adamwa...@blueyonder.co.uk> wrote:
>>> Interestingly the one (minor) issue he raised
>>> with the wiring was the lack of cross bonding of the CH system at
>>> the boiler; said he trusted me to install it today and wouldn't
>>> mention it on the report - I don't think that would have happened
>>> when he first arrived!
>
>> I cannot see the point in cross bonding the CH at the boiler. There
>> is no requirement to do it.
>
> I did wonder. If that were deemed necessary, you'd have to cross bond
> every rad too?
It used to be quite handy to cross bond a boiler if it was next to a
bathroom and could be used for the bathrooms supplementary bonding. However
in this case the 17th edition rules apply and there is no need for
supplementary bonding.
--
Adam
ARWadsworth
> I found an electrician willing and able to come in yesterday.
What, you didn't ask me!
> First
> thing he looks at is my newly installed CU and with much sucking of
> teeth says "well this is a bit of a mess isn't it" - he was referring
> to the sequential numbers on the neutral terminals not matching up to
> those on the MCBs. Oh puh-leaze...
Hardly a major fault. I certainly would not have made a comment about it.
> I explained how I'd tracked down the fault to one leg of the ring with
> 90% certainty using Mr Reagan's above method; however he didn't
> understand (or believe?) the technique and started his diagnostics
> from scratch; took him two hours with his Megger to reach the same
> conclusion I had. By this time I think he'd cottoned on that I
> wasn't a total muppet and aided with copious quantities of tea,
> relations had thawed somewhat.
It should hve taken him 5 minutes if had listened
> In the end he decided to break into the wall at ceiling level to cut
> the affected cable for further testing (it was impossible to access
> it above the ceiling, which was where I'd come unstuck myself); that
> isolated the problem to a break between the ceiling and the socket
> below. Fortunately he was able to pull a new length of cable up
> through the capping, and then connect that with a jcb above the
> ceiling, so just leaving me a small hole to fill at ceiling level.
He did well on that bit.
> So - FYI here's the offending damage!:
> http://img96.imageshack.us/img96/1548/cablecropped.jpg
A brilliant picture BTW.
> Evidently caused by a picture hook or screw right into the cable.
> Because I'd had the room plaster skimmed last week, there was no
> evidence of this. The live wire is burned about 50% through but still
> intact.
Always do the electrical testing first.
--
Adam
Ronald Raygun
> Lobster <davidlobs...@hotmail.com> wrote:
>
>
>> I found an electrician willing and able to come in yesterday.
>
> What, you didn't ask me!
He would have, but you were busy with your neighbour's car.
ARWadsworth
It would have got me out of jump starting the neighbours car.
Mind you if David is 300 miles away from me I suppose he would not want to
pay my petrol costs.
--
Adam
A.Lee
This came up on my 17th Ed. course, and the Instructor said it was more
to do with the Gassafe regs - to make sure the boiler is earthed.
I've seen it where there were 5 earth tags/cables on the pipes going
into the boiler
Though my gas fitting mate says it's bollocks, he just makes sure the
gas and water pipes are properly earthed.
alan.
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Lobster
I think the last time I came across this issue (~5 years ago, pre-17th
edn) it was the gasman who told me I needed to do this, so I duly
installed 5 interconnected earth clamps. Then the sparky came round to
do the PIR test, and told me it wasn't actually necessary (mind you, the
same guy insisted on supplementary bonding in the kitchen, so go figure...)
On the current occasion when the new electrician raised it, I did query
whether cross binding was definitely a requirement these days and he
said yes, always has been and still is. Should I not bother?
David
ARWadsworth
You might as well do it now. After all you may one day want the bloke back
to do other work.
And the bit about the neutral bar in the CU is here.
--
Cheers
Adam
Andrew Mawson
"ARWadsworth" <adamwa...@blueyonder.co.uk> wrote in message
news:R_iRo.113391$DC7....@newsfe16.ams2...
But that link does say that in single phase consumer units neutrals
can be sequentially placed so not needing labelling, and implies it's
only needed in some three phase boards. In the three phase boards I've
installed here on the farm, all have labels adjacent to the neutral
bar identifying breaker numbers, so again not needed.
AWEM
ARWadsworth
It is a long winded way of saying that the neutrals must be clearly marked
or identifiable. Something that David must not have done, although with
three circuits between two rcds it would only take about 3 seconds to work
it out.
--
Adam