Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss
Garden lighting trips RCD
179 views
Skip to first unread message
Richard Russell
Jun 18, 2013, 10:19:47 AM6/18/13
to
We have an extensive, professionally installed, garden lighting system
which has recently started tripping its dedicated RCD. I have
eliminated all the bulbs, luminaires and accessible cables which,
sadly, means the problem is almost certainly in one of the many
'waterproof' underground connection boxes. How on earth does one
trace a fault like this? Dig up the entire garden?
Richard.
http://www.rtrussell.co.uk/
which has recently started tripping its dedicated RCD. I have
eliminated all the bulbs, luminaires and accessible cables which,
sadly, means the problem is almost certainly in one of the many
'waterproof' underground connection boxes. How on earth does one
trace a fault like this? Dig up the entire garden?
Richard.
http://www.rtrussell.co.uk/
Bill
Jun 18, 2013, 11:48:10 AM6/18/13
to
In message
<b73d4be2-ac33-4535...@hs10g2000vbb.googlegroups.com>,
Richard Russell <ne...@rtrussell.co.uk> writes
I think the answer is "Yes!".
My son's house has an RCD in the garage that feeds the cooker, an
outside plantroom (that feeds some garden lights, pumps and other
things), a summerhouse with leaking roof, some street lights up his
drive and the filter and pump in the fish pond.
Every few days, in the middle of cooking a meal, the RCD would trip. I
took my old wind up megger down there, but was met with contempt.
Disconnecting the feed on from the plant room cured the problem so he
re-wired the summerhouse - no change. Replaced and rewired the outside
box feeding the pond. No change. Bought and installed a new submersible
pump. No change. He bought and installed some awful cylindrical in-line
connectors between the new box and the pond pump and separately the
filter. It was the filter. Dismantled it and discovered water had leaked
past a seal. Dried out and re-gunged and so far it has been OK.
This took us weeks to find, and at least he now has more knowledge of
the distribution (we still don't know how the street lights are wired)
and some of the installation is good. He did the wiring. I went along to
be a second pair of hands and to do the semaphore during testing.
I must find out what the in-line connectors were so that I am never
tempted to use them.
--
Bill
<b73d4be2-ac33-4535...@hs10g2000vbb.googlegroups.com>,
Richard Russell <ne...@rtrussell.co.uk> writes
My son's house has an RCD in the garage that feeds the cooker, an
outside plantroom (that feeds some garden lights, pumps and other
things), a summerhouse with leaking roof, some street lights up his
drive and the filter and pump in the fish pond.
Every few days, in the middle of cooking a meal, the RCD would trip. I
took my old wind up megger down there, but was met with contempt.
Disconnecting the feed on from the plant room cured the problem so he
re-wired the summerhouse - no change. Replaced and rewired the outside
box feeding the pond. No change. Bought and installed a new submersible
pump. No change. He bought and installed some awful cylindrical in-line
connectors between the new box and the pond pump and separately the
filter. It was the filter. Dismantled it and discovered water had leaked
past a seal. Dried out and re-gunged and so far it has been OK.
This took us weeks to find, and at least he now has more knowledge of
the distribution (we still don't know how the street lights are wired)
and some of the installation is good. He did the wiring. I went along to
be a second pair of hands and to do the semaphore during testing.
I must find out what the in-line connectors were so that I am never
tempted to use them.
--
Bill
Richard Russell
Jun 18, 2013, 12:10:18 PM6/18/13
to
What would be the acceptability, under the regs, of fitting an
isolating transformer? No chance of tripping the RCD then, leakage or
no leakage!
Richard.
http://www.rtrussell.co.uk/
isolating transformer? No chance of tripping the RCD then, leakage or
no leakage!
Richard.
http://www.rtrussell.co.uk/
ARW
Jun 18, 2013, 1:33:43 PM6/18/13
to
Richard Russell wrote:
> On Jun 18, 4:48 pm, Bill <Billabo...@gmail.com> wrote:
>> I think the answer is "Yes!".
>
> What would be the acceptability, under the regs, of fitting an
> isolating transformer? No chance of tripping the RCD then, leakage or
> no leakage!
>
Apart from the lack of the required RCD protection?
> On Jun 18, 4:48 pm, Bill <Billabo...@gmail.com> wrote:
>> I think the answer is "Yes!".
>
> What would be the acceptability, under the regs, of fitting an
> isolating transformer? No chance of tripping the RCD then, leakage or
> no leakage!
>
--
Adam
Brian Gaff
Jun 18, 2013, 2:22:56 PM6/18/13
to
Well if you know the route it takes one could start at the furthest one and
disconnect, then reconnect if it still trips and move closer etc. the snag
occurs if its branched ie several circuits or you do not know what goes
where first!
Brian
--
From the Sofa of Brian Gaff Reply address is active
"Richard Russell" <ne...@rtrussell.co.uk> wrote in message
news:b73d4be2-ac33-4535...@hs10g2000vbb.googlegroups.com...
disconnect, then reconnect if it still trips and move closer etc. the snag
occurs if its branched ie several circuits or you do not know what goes
where first!
Brian
--
From the Sofa of Brian Gaff Reply address is active
"Richard Russell" <ne...@rtrussell.co.uk> wrote in message
news:b73d4be2-ac33-4535...@hs10g2000vbb.googlegroups.com...
Brian Gaff
Jun 18, 2013, 2:25:22 PM6/18/13
to
Ah and then just watch for the smoke when the leak gets worse, brill.
Brian
--
From the Sofa of Brian Gaff Reply address is active
"Richard Russell" <ne...@rtrussell.co.uk> wrote in message
news:7b9378ec-7663-440f...@e7g2000vbq.googlegroups.com...
--
From the Sofa of Brian Gaff Reply address is active
"Richard Russell" <ne...@rtrussell.co.uk> wrote in message
meow...@care2.com
Jun 18, 2013, 3:38:33 PM6/18/13
to
If its a practical option to feed it off more than one rcd, that would ensure half of it stays on in a fault.
NT
Richard Russell
Jun 18, 2013, 5:59:32 PM6/18/13
to
On Jun 18, 7:22 pm, "Brian Gaff" <Bria...@blueyonder.co.uk> wrote:
> Well if you know the route it takes one could start at the furthest one and
> disconnect, then reconnect if it still trips and move closer etc. the snag
> occurs if its branched ie several circuits or you do not know what goes
> where first!
Every single connection is in a buried waterproof box - there are a
> Well if you know the route it takes one could start at the furthest one and
> disconnect, then reconnect if it still trips and move closer etc. the snag
> occurs if its branched ie several circuits or you do not know what goes
> where first!
lot of them - so such an approach would involve lots of digging (in a
mature garden with pretty much the entire ground surface covered with
plants and/or weed membrane and gravel). It's not very practical!
Richard.
http://www.rtrussell.co.uk/
Richard Russell
Jun 18, 2013, 6:03:21 PM6/18/13
to
On Jun 18, 6:33 pm, "ARW" <adamwadswo...@blueyonder.co.uk> wrote:
> Apart from the lack of the required RCD protection?
I don't know what the letter of the regs says, but if an isolation
> Apart from the lack of the required RCD protection?
transformer (with a 115-0-115 secondary) is considered safe for on-
site power tools I dont really see what the objection would be to
using one for garden lighting.
Richard.
http://www.rtrussell.co.uk/
Tim Watts
Jun 18, 2013, 6:46:19 PM6/18/13
to
counts as ELV.
--
Tim Watts Personal Blog: http://squiddy.blog.dionic.net/
http://www.sensorly.com/ Crowd mapping of 2G/3G/4G mobile signal coverage
Reading this on the web? See:
http://wiki.diyfaq.org.uk/index.php?title=Usenet
Richard Russell
Jun 18, 2013, 7:03:21 PM6/18/13
to
On Jun 18, 11:46 pm, Tim Watts <tw+use...@dionic.net> wrote:
> That's 55-0-55 aka 110V you're thinking of and the 55V (relative to earth)
> counts as ELV.
Fair point, but isolation transformers with a 230v secondary are sold
> That's 55-0-55 aka 110V you're thinking of and the 55V (relative to earth)
> counts as ELV.
as 'safety site transformers', which is what I was meaning. For
example these from RS:
http://uk.rs-online.com/web/p/safety-site-transformers/0405565/
http://uk.rs-online.com/web/p/safety-site-transformers/2604238/
Our house is of a vintage (built six years ago) when no RCD protection
was required on the lighting circuits, so in that context I can't get
myself too worked up about garden lighting with no RCD protection,
especially if it's only running at 115 volts wrt ground.
Richard.
http://www.rtrussell.co.uk/
Tim Watts
Jun 19, 2013, 3:26:43 AM6/19/13
to
On Wednesday 19 June 2013 00:03 Richard Russell wrote in uk.d-i-y:
> On Jun 18, 11:46 pm, Tim Watts <tw+use...@dionic.net> wrote:
>> That's 55-0-55 aka 110V you're thinking of and the 55V (relative to
>> earth) counts as ELV.
>
> Fair point, but isolation transformers with a 230v secondary are sold
> as 'safety site transformers', which is what I was meaning. For
> example these from RS:
>
> http://uk.rs-online.com/web/p/safety-site-transformers/0405565/
> http://uk.rs-online.com/web/p/safety-site-transformers/2604238/
I will have to check chapter and verse - but even if fully floating, relying
> On Jun 18, 11:46 pm, Tim Watts <tw+use...@dionic.net> wrote:
>> That's 55-0-55 aka 110V you're thinking of and the 55V (relative to
>> earth) counts as ELV.
>
> Fair point, but isolation transformers with a 230v secondary are sold
> as 'safety site transformers', which is what I was meaning. For
> example these from RS:
>
> http://uk.rs-online.com/web/p/safety-site-transformers/0405565/
> http://uk.rs-online.com/web/p/safety-site-transformers/2604238/
on it is a bad idea IMO.
> Our house is of a vintage (built six years ago) when no RCD protection
> was required on the lighting circuits, so in that context I can't get
> myself too worked up about garden lighting with no RCD protection,
> especially if it's only running at 115 volts wrt ground.
particularly special case as you both have enhanced shock risk (wet
ground/rain/etc) *and* you are more likely to expose a member of the public
to risk (eg visitors).
> Richard.
> http://www.rtrussell.co.uk/
meow...@care2.com
Jun 19, 2013, 4:33:51 AM6/19/13
to
On Tuesday, June 18, 2013 10:59:32 PM UTC+1, Richard Russell wrote:
> Every single connection is in a buried waterproof box - there are a
> lot of them - so such an approach would involve lots of digging (in a
> mature garden with pretty much the entire ground surface covered with
> plants and/or weed membrane and gravel). It's not very practical!
If its really not doable, I'm struggling to see a better option than going 55-0-55.
> Every single connection is in a buried waterproof box - there are a
> lot of them - so such an approach would involve lots of digging (in a
> mature garden with pretty much the entire ground surface covered with
> plants and/or weed membrane and gravel). It's not very practical!
NT
Richard Russell
Jun 19, 2013, 4:38:12 AM6/19/13
to
On Wednesday, June 19, 2013 8:26:43 AM UTC+1, Tim Watts wrote:
> "Only 115V"? I think you *should* worry about that - outside is a
> particularly special case as you both have enhanced shock risk (wet
> ground/rain/etc) *and* you are more likely to expose a member of
> the public to risk (eg visitors).
I can't say I agree. AIUI, the requirement to have RCD protection at all on garden lighting circuits is a fairly recent one. In addition, garden luminaires are far better protected from accidental contact than a domestic (bayonet or screw) light fitting, because of the weatherproofing requirement.
> "Only 115V"? I think you *should* worry about that - outside is a
> particularly special case as you both have enhanced shock risk (wet
> ground/rain/etc) *and* you are more likely to expose a member of
> the public to risk (eg visitors).
To gain access to the bulb, let alone remove it to expose a live terminal, typically requires unscrewing a watertight cover - something which I know from experience is not easy even when you want to do it! The idea that a visitor might unscrew one of these covers, remove the bulb (presumably lit) and poke their finger into the exposed socket - mostly GU10 so that's not easy - seems wildly implausible to me.
As it happens the point is moot anyway. As an experiment I bypassed the RCD so I could power up the circuit for a few hours. The result is that (maybe through some local heating drying out the moisture) the leak is now reduced below the trip threshold and it's running fine again with the RCD re-instated. The problem may recur, of course, but I'll worry about that if and when it happens.
Richard.
http://www.rtrussell.co.uk/
Dave Liquorice
Jun 19, 2013, 7:53:36 AM6/19/13
to
On Wed, 19 Jun 2013 01:38:12 -0700 (PDT), Richard Russell wrote:
>> "Only 115V"? I think you *should* worry about that - outside is a
>> particularly special case as you both have enhanced shock risk
(wet
>> ground/rain/etc) *and* you are more likely to expose a member of
>> the public to risk (eg visitors).
>
> I can't say I agree. AIUI, the requirement to have RCD protection at
> all on garden lighting circuits is a fairly recent one.
Think it's any circuit "exported" not just lighting. B-)
>> "Only 115V"? I think you *should* worry about that - outside is a
>> particularly special case as you both have enhanced shock risk
(wet
>> ground/rain/etc) *and* you are more likely to expose a member of
>> the public to risk (eg visitors).
>
> I can't say I agree. AIUI, the requirement to have RCD protection at
> all on garden lighting circuits is a fairly recent one.
But given the choice between a traditional L 230 V wrt ground and N
bonded to ground circuit and a fully floating nominal 115V L and N
wrt to ground but 230 V l to N I'd prefer the latter. If you touch
either it drops to essentially ground you'll still get a belt but
nothing like the one you'd get from touching the L in the first case.
Problems come when there is a fault to earth on one side of the
fullly floating circuit and you touch the other...
--
Cheers
Dave.
Dave Liquorice
Jun 19, 2013, 7:58:56 AM6/19/13
to
On Tue, 18 Jun 2013 14:59:32 -0700 (PDT), Richard Russell wrote:
> Every single connection is in a buried waterproof box -
Design failure, there is no such thing as a "waterproof box" unless
> Every single connection is in a buried waterproof box -
you fill it with something to stop water getting in, be that a
potting compound or hard setting tar.
If there is a void water will get in, either by capillary action
through any seals or as water vapour and then condensation through
the seals or even the box material itself.
They should have been left accessable in some way or marked, At the
very least an accurate map of cable routes and joins made.
--
Cheers
Dave.
meow...@care2.com
Jun 19, 2013, 9:00:47 AM6/19/13
to
On Wednesday, June 19, 2013 9:38:12 AM UTC+1, Richard Russell wrote:
> As it happens the point is moot anyway. As an experiment I bypassed the RCD so I could power up the circuit for a few hours. The result is that (maybe through some local heating drying out the moisture) the leak is now reduced below the trip threshold and it's running fine again with the RCD re-instated. The problem may recur, of course, but I'll worry about that if and when it happens.
it inevitably will.
> As it happens the point is moot anyway. As an experiment I bypassed the RCD so I could power up the circuit for a few hours. The result is that (maybe through some local heating drying out the moisture) the leak is now reduced below the trip threshold and it's running fine again with the RCD re-instated. The problem may recur, of course, but I'll worry about that if and when it happens.
Converting to 12-0-12v is another option
NT
John Rumm
Jun 19, 2013, 11:06:23 AM6/19/13
to
On 19/06/2013 09:38, Richard Russell wrote:
> On Wednesday, June 19, 2013 8:26:43 AM UTC+1, Tim Watts wrote:
>> "Only 115V"? I think you *should* worry about that - outside is a
>> particularly special case as you both have enhanced shock risk
>> (wet ground/rain/etc) *and* you are more likely to expose a member
>> of the public to risk (eg visitors).
>
> I can't say I agree. AIUI, the requirement to have RCD protection at
> all on garden lighting circuits is a fairly recent one.
Not especially no. Outside circuits in general require RCD protection.
> On Wednesday, June 19, 2013 8:26:43 AM UTC+1, Tim Watts wrote:
>> "Only 115V"? I think you *should* worry about that - outside is a
>> particularly special case as you both have enhanced shock risk
>> (wet ground/rain/etc) *and* you are more likely to expose a member
>> of the public to risk (eg visitors).
>
> I can't say I agree. AIUI, the requirement to have RCD protection at
> all on garden lighting circuits is a fairly recent one.
> In addition,
> garden luminaires are far better protected from accidental contact
> than a domestic (bayonet or screw) light fitting, because of the
> weatherproofing requirement.
short on a lamp and the case is not earthed, and only under certain
circumstances is there enough leakage to earth to cause your trip. Still
fancy leaning against that lamp post with the RCD disabled?
> To gain access to the bulb, let alone remove it to expose a live
> terminal, typically requires unscrewing a watertight cover -
> something which I know from experience is not easy even when you want
> to do it! The idea that a visitor might unscrew one of these covers,
> remove the bulb (presumably lit) and poke their finger into the
> exposed socket - mostly GU10 so that's not easy - seems wildly
> implausible to me.
> As it happens the point is moot anyway. As an experiment I bypassed
> the RCD so I could power up the circuit for a few hours. The result
> is that (maybe through some local heating drying out the moisture)
> the leak is now reduced below the trip threshold and it's running
> fine again with the RCD re-instated. The problem may recur, of
> course, but I'll worry about that if and when it happens.
--
Cheers,
John.
/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/
Bill
Jun 19, 2013, 1:09:34 PM6/19/13
to
In message <qOudnfxjAP5sVVzM...@brightview.co.uk>, John
Rumm <see.my.s...@nowhere.null> writes
until a period of rain, then walk round the garden with a candle.
--
Bill
Rumm <see.my.s...@nowhere.null> writes
>> As it happens the point is moot anyway. As an experiment I bypassed
>> the RCD so I could power up the circuit for a few hours. The result
>> is that (maybe through some local heating drying out the moisture)
>> the leak is now reduced below the trip threshold and it's running
>> fine again with the RCD re-instated. The problem may recur, of
>> course, but I'll worry about that if and when it happens.
>
>Ah, the ostrich algorithm ;-)
>
I've got the answer. Bypass the RCD, insert a series diode, let it run
>> the RCD so I could power up the circuit for a few hours. The result
>> is that (maybe through some local heating drying out the moisture)
>> the leak is now reduced below the trip threshold and it's running
>> fine again with the RCD re-instated. The problem may recur, of
>> course, but I'll worry about that if and when it happens.
>
>Ah, the ostrich algorithm ;-)
>
until a period of rain, then walk round the garden with a candle.
--
Bill
John Rumm
Jun 19, 2013, 6:21:21 PM6/19/13
to
On 18/06/2013 20:38, meow...@care2.com wrote:
> On Tuesday, June 18, 2013 3:19:47 PM UTC+1, Richard Russell wrote:
>
>> We have an extensive, professionally installed, garden lighting
>> system which has recently started tripping its dedicated RCD. I
>> have eliminated all the bulbs, luminaires and accessible cables
>> which, sadly, means the problem is almost certainly in one of the
>> many 'waterproof' underground connection boxes. How on earth does
>> one trace a fault like this? Dig up the entire garden? Richard.
>> http://www.rtrussell.co.uk/
>
> Divide & conquer. Simple as that. Its going to mean undoing many
> connections as you megger it all bit by bit.
If you go the binary chop route, you can eliminate 3/4s of the circuit
> On Tuesday, June 18, 2013 3:19:47 PM UTC+1, Richard Russell wrote:
>
>> We have an extensive, professionally installed, garden lighting
>> system which has recently started tripping its dedicated RCD. I
>> have eliminated all the bulbs, luminaires and accessible cables
>> which, sadly, means the problem is almost certainly in one of the
>> many 'waterproof' underground connection boxes. How on earth does
>> one trace a fault like this? Dig up the entire garden? Richard.
>> http://www.rtrussell.co.uk/
>
> Divide & conquer. Simple as that. Its going to mean undoing many
> connections as you megger it all bit by bit.
by digging up just two of the junctions...
Richard Russell
Jun 19, 2013, 6:50:07 PM6/19/13
to
On Jun 19, 4:06 pm, John Rumm <see.my.signat...@nowhere.null> wrote:
> So lets say the cause of the fault is that you have a live to case
> short on a lamp and the case is not earthed
That's a double-fault scenario (live-to-case short *and* case not
> So lets say the cause of the fault is that you have a live to case
> short on a lamp and the case is not earthed
earthed). One doesn't normally attempt to protect against such
unlikely occurrences. In any case an entirely disconnected earth
isn't very plausible when the stainless steel lamp column physically
enters the ground!
> Ah, the ostrich algorithm ;-)
inevitably be difficult, expensive and time-consuming, putting it off
as long as possible (without compromising safety) makes perfect sense!
Richard.
http://www.rtrussell.co.uk/
Windmill
Jun 19, 2013, 6:36:07 PM6/19/13
to
Reflectometers, which would show the location of discontinuities in a
transmission line by the squiggles on a built-in oscilloscope screen.
Hard to interpret and I imagine it would be even more difficult if all
you were looking for was a fairly high leakage resistance rather than a
short, and even more difficult if the circuit branched.
But treating live and earth as a transmission line and using a TDR to
examine its characteristics might just possibly reveal something.
OTOH one might have more luck with a couple of bent hazel sticks !
--
Windmill, Til...@Nonetel.com Use t m i l l
J.R.R. Tolkien:- @ O n e t e l . c o m
All that is gold does not glister / Not all who wander are lost
Windmill
Jun 19, 2013, 8:38:12 PM6/19/13
to
Tim Watts <tw+u...@dionic.net> writes:
>On Wednesday 19 June 2013 00:03 Richard Russell wrote in uk.d-i-y:
>> On Jun 18, 11:46 pm, Tim Watts <tw+use...@dionic.net> wrote:
>>> That's 55-0-55 aka 110V you're thinking of and the 55V (relative to
>>> earth) counts as ELV.
>>
>> Fair point, but isolation transformers with a 230v secondary are sold
>> as 'safety site transformers', which is what I was meaning. For
>> example these from RS:
>>
>> http://uk.rs-online.com/web/p/safety-site-transformers/0405565/
>> http://uk.rs-online.com/web/p/safety-site-transformers/2604238/
>I will have to check chapter and verse - but even if fully floating, relying
>on it is a bad idea IMO.
>
>> Our house is of a vintage (built six years ago) when no RCD protection
>> was required on the lighting circuits, so in that context I can't get
>> myself too worked up about garden lighting with no RCD protection,
>> especially if it's only running at 115 volts wrt ground.
>"Only 115V"? I think you *should* worry about that - outside is a
>particularly special case as you both have enhanced shock risk (wet
>ground/rain/etc) *and* you are more likely to expose a member of the public
>to risk (eg visitors).
In N. America they use 115v but they also use RCDs (they call them
>On Wednesday 19 June 2013 00:03 Richard Russell wrote in uk.d-i-y:
>> On Jun 18, 11:46 pm, Tim Watts <tw+use...@dionic.net> wrote:
>>> That's 55-0-55 aka 110V you're thinking of and the 55V (relative to
>>> earth) counts as ELV.
>>
>> Fair point, but isolation transformers with a 230v secondary are sold
>> as 'safety site transformers', which is what I was meaning. For
>> example these from RS:
>>
>> http://uk.rs-online.com/web/p/safety-site-transformers/0405565/
>> http://uk.rs-online.com/web/p/safety-site-transformers/2604238/
>I will have to check chapter and verse - but even if fully floating, relying
>on it is a bad idea IMO.
>
>> Our house is of a vintage (built six years ago) when no RCD protection
>> was required on the lighting circuits, so in that context I can't get
>> myself too worked up about garden lighting with no RCD protection,
>> especially if it's only running at 115 volts wrt ground.
>"Only 115V"? I think you *should* worry about that - outside is a
>particularly special case as you both have enhanced shock risk (wet
>ground/rain/etc) *and* you are more likely to expose a member of the public
>to risk (eg visitors).
GFIs) with a sensitivity of only 5 mA. not 30 mA.
So they're still worried even though the voltage is lower.
Windmill
Jun 19, 2013, 9:30:36 PM6/19/13
to
Richard Russell <ne...@rtrussell.co.uk> writes:
>On Jun 19, 4:06=A0pm, John Rumm <see.my.signat...@nowhere.null> wrote:
>> So lets say the cause of the fault is that =A0you have a live to case
be about twice the resistance of one column to earth) you may be
surprised - it'll likely be of the order of K ohms.
>On Jun 19, 4:06=A0pm, John Rumm <see.my.signat...@nowhere.null> wrote:
>> So lets say the cause of the fault is that =A0you have a live to case
>> short on a lamp and the case is not earthed
>That's a double-fault scenario (live-to-case short *and* case not
>earthed). One doesn't normally attempt to protect against such
>unlikely occurrences. In any case an entirely disconnected earth
>isn't very plausible when the stainless steel lamp column physically
>enters the ground!
If you measure the resistance between two of those columns (which will
>That's a double-fault scenario (live-to-case short *and* case not
>earthed). One doesn't normally attempt to protect against such
>unlikely occurrences. In any case an entirely disconnected earth
>isn't very plausible when the stainless steel lamp column physically
>enters the ground!
be about twice the resistance of one column to earth) you may be
surprised - it'll likely be of the order of K ohms.
tony sayer
Jun 20, 2013, 7:13:20 AM6/20/13
to
In article <Monw4...@freebie.onetel.net.uk>, Windmill <spam-no-
sp...@Onetel.net.uk.invalid> scribeth thus
co-ax cable it showed it up very accurately. Two discontinues one major
one not so. There used to be a design around for a brew you own but
needed a scope to go with it not that practical. Theres a BT test unit
comes up on ebay from time to time thats very good...
>But treating live and earth as a transmission line and using a TDR to
>examine its characteristics might just possibly reveal something.
>
>OTOH one might have more luck with a couple of bent hazel sticks !
>
Well that might tell you the line is there but not much else. Seen it
done on buried water pipes, seems to work very well with some people but
not all..
--
Tony Sayer
sp...@Onetel.net.uk.invalid> scribeth thus
>Richard Russell <ne...@rtrussell.co.uk> writes:
>
>>We have an extensive, professionally installed, garden lighting system
>>which has recently started tripping its dedicated RCD. I have
>>eliminated all the bulbs, luminaires and accessible cables which,
>>sadly, means the problem is almost certainly in one of the many
>>'waterproof' underground connection boxes. How on earth does one
>>trace a fault like this? Dig up the entire garden?
>
>Donkey's moons ago there used to be things called TDRs, Time Domain
>Reflectometers, which would show the location of discontinuities in a
>transmission line by the squiggles on a built-in oscilloscope screen.
>
>Hard to interpret and I imagine it would be even more difficult if all
>you were looking for was a fairly high leakage resistance rather than a
>short, and even more difficult if the circuit branched.
>
There're still around used on the other week to find a fault on a buried
>
>>We have an extensive, professionally installed, garden lighting system
>>which has recently started tripping its dedicated RCD. I have
>>eliminated all the bulbs, luminaires and accessible cables which,
>>sadly, means the problem is almost certainly in one of the many
>>'waterproof' underground connection boxes. How on earth does one
>>trace a fault like this? Dig up the entire garden?
>
>Donkey's moons ago there used to be things called TDRs, Time Domain
>Reflectometers, which would show the location of discontinuities in a
>transmission line by the squiggles on a built-in oscilloscope screen.
>
>Hard to interpret and I imagine it would be even more difficult if all
>you were looking for was a fairly high leakage resistance rather than a
>short, and even more difficult if the circuit branched.
>
co-ax cable it showed it up very accurately. Two discontinues one major
one not so. There used to be a design around for a brew you own but
needed a scope to go with it not that practical. Theres a BT test unit
comes up on ebay from time to time thats very good...
>But treating live and earth as a transmission line and using a TDR to
>examine its characteristics might just possibly reveal something.
>
>OTOH one might have more luck with a couple of bent hazel sticks !
>
done on buried water pipes, seems to work very well with some people but
not all..
--
Tony Sayer
meow...@care2.com
Jun 20, 2013, 1:13:19 PM6/20/13
to
On Wednesday, June 19, 2013 11:21:21 PM UTC+1, John Rumm wrote:
> On 18/06/2013 20:38, meow...@care2.com wrote:
> > On Tuesday, June 18, 2013 3:19:47 PM UTC+1, Richard Russell wrote:
> >> We have an extensive, professionally installed, garden lighting
> >> system which has recently started tripping its dedicated RCD. I
> >> have eliminated all the bulbs, luminaires and accessible cables
> >> which, sadly, means the problem is almost certainly in one of the
> >> many 'waterproof' underground connection boxes. How on earth does
> >> one trace a fault like this? Dig up the entire garden? Richard.
> >> http://www.rtrussell.co.uk/
> > Divide & conquer. Simple as that. Its going to mean undoing many
> > connections as you megger it all bit by bit.
> If you go the binary chop route, you can eliminate 3/4s of the circuit
> by digging up just two of the junctions...
Yup. You've got a fair chance of getting a lot of the circuit operational quite quickly. But it is also possible the OP has more than one leaky cable or jbox, or that the leak is in the one and only feed line for the lot.
> On 18/06/2013 20:38, meow...@care2.com wrote:
> > On Tuesday, June 18, 2013 3:19:47 PM UTC+1, Richard Russell wrote:
> >> We have an extensive, professionally installed, garden lighting
> >> system which has recently started tripping its dedicated RCD. I
> >> have eliminated all the bulbs, luminaires and accessible cables
> >> which, sadly, means the problem is almost certainly in one of the
> >> many 'waterproof' underground connection boxes. How on earth does
> >> one trace a fault like this? Dig up the entire garden? Richard.
> >> http://www.rtrussell.co.uk/
> > Divide & conquer. Simple as that. Its going to mean undoing many
> > connections as you megger it all bit by bit.
> If you go the binary chop route, you can eliminate 3/4s of the circuit
> by digging up just two of the junctions...
There's really no other way to fix it than divide & conquer. The only other options are workarounds that keep going with wet cable or jboxes, which have a high risk of later total failure.
With luck you may be able to trace much of it with a basic metal detector.
NT
Adam Funk
Jun 20, 2013, 4:15:11 PM6/20/13
to
sockets in kitchens & bathrooms & outdoors.
Andy Wade
Jun 21, 2013, 6:57:09 PM6/21/13
to
On 19/06/2013 23:36, Windmill wrote:
> But treating live and earth as a transmission line and using a TDR to
> examine its characteristics might just possibly reveal something.
Or not... With the 'fault' being a fairly high resistance leak to earth
> But treating live and earth as a transmission line and using a TDR to
> examine its characteristics might just possibly reveal something.
the reflection coefficient probably won't be high enough to show up.
> OTOH one might have more luck with a couple of bent hazel sticks !
Disconnect the feed-point from the RCD. Strap the L & N outgoing
conductors together and energise them at mains voltage via a
precautionary low value fuse (1 or 2 A, say). The point(s) of leakage
will now be injecting some current into the soil. If you're worried
about safety then reduce the applied voltage using a suitable
transformer or auto-transformer. 50 V might be enough.
Now use a highish impedance AC voltmeter (an ordinary DMM will do) and
probe for ground potential gradients - i.e. earth one side of the meter
to a reference, the mains earth should do, via a long flying lead. On
the other side, rig up a probe a few inches long to stick in the ground
- this ought to a have an insulated handle for obvious reasons. Probe
around, following the cable routes, if known. Look for the highest
voltage and dig there.
If water has got into a joint box it will only be a matter of time
before the situation develops into a low impedance L-N fault. I fear
that feeding via an isolating transformer would only give a short-term fix.
--
Andy
John Rumm
Jun 21, 2013, 10:06:01 PM6/21/13
to
On 21/06/2013 23:57, Andy Wade wrote:
> On 19/06/2013 23:36, Windmill wrote:
>
>> But treating live and earth as a transmission line and using a TDR to
>> examine its characteristics might just possibly reveal something.
>
> Or not... With the 'fault' being a fairly high resistance leak to earth
> the reflection coefficient probably won't be high enough to show up.
>
>> OTOH one might have more luck with a couple of bent hazel sticks !
>
> Sort of. My suggestion is as follows:
>
> Disconnect the feed-point from the RCD. Strap the L & N outgoing
> conductors together and energise them at mains voltage via a
> precautionary low value fuse (1 or 2 A, say). The point(s) of leakage
> will now be injecting some current into the soil. If you're worried
> about safety then reduce the applied voltage using a suitable
> transformer or auto-transformer. 50 V might be enough.
>
> Now use a highish impedance AC voltmeter (an ordinary DMM will do) and
> probe for ground potential gradients - i.e. earth one side of the meter
> to a reference, the mains earth should do, via a long flying lead. On
> the other side, rig up a probe a few inches long to stick in the ground
> - this ought to a have an insulated handle for obvious reasons. Probe
> around, following the cable routes, if known. Look for the highest
> voltage and dig there.
Nice plan...
> On 19/06/2013 23:36, Windmill wrote:
>
>> But treating live and earth as a transmission line and using a TDR to
>> examine its characteristics might just possibly reveal something.
>
> Or not... With the 'fault' being a fairly high resistance leak to earth
> the reflection coefficient probably won't be high enough to show up.
>
>> OTOH one might have more luck with a couple of bent hazel sticks !
>
> Sort of. My suggestion is as follows:
>
> Disconnect the feed-point from the RCD. Strap the L & N outgoing
> conductors together and energise them at mains voltage via a
> precautionary low value fuse (1 or 2 A, say). The point(s) of leakage
> will now be injecting some current into the soil. If you're worried
> about safety then reduce the applied voltage using a suitable
> transformer or auto-transformer. 50 V might be enough.
>
> Now use a highish impedance AC voltmeter (an ordinary DMM will do) and
> probe for ground potential gradients - i.e. earth one side of the meter
> to a reference, the mains earth should do, via a long flying lead. On
> the other side, rig up a probe a few inches long to stick in the ground
> - this ought to a have an insulated handle for obvious reasons. Probe
> around, following the cable routes, if known. Look for the highest
> voltage and dig there.
Might be worth adding a step of doing an additional probing before
energising the circuit, just to establish that you are not going to be
lead up the garden path (so to speak) by stray ground currents from
other sources not connected with the actual circuit in question.
> If water has got into a joint box it will only be a matter of time
> before the situation develops into a low impedance L-N fault. I fear
> that feeding via an isolating transformer would only give a short-term fix.
warm if you are unlucky.
Andy Wade
Jun 22, 2013, 5:52:47 PM6/22/13
to
On 22/06/2013 03:06, John Rumm wrote:
> Nice plan...
>
> Might be worth adding a step of doing an additional probing before
> energising the circuit, just to establish that you are not going to be
> lead up the garden path (so to speak) by stray ground currents from
> other sources not connected with the actual circuit in question.
Good idea - and in retrospect my suggestion to use mains earth as the
> Nice plan...
>
> Might be worth adding a step of doing an additional probing before
> energising the circuit, just to establish that you are not going to be
> lead up the garden path (so to speak) by stray ground currents from
> other sources not connected with the actual circuit in question.
voltmeter's reference point wasn't too clever, especially it's PME. A
'clean' reference spike somewhere in the garden, but known to be well
away from the lighting cables, should be a much better bet.
--
Andy
meow...@care2.com
Jun 23, 2013, 3:16:24 AM6/23/13
to
On Saturday, June 22, 2013 3:06:01 AM UTC+1, John Rumm wrote:
> On 21/06/2013 23:57, Andy Wade wrote:
> > On 19/06/2013 23:36, Windmill wrote:
> > Sort of. My suggestion is as follows:
> >
> > Disconnect the feed-point from the RCD. Strap the L & N outgoing
> > conductors together and energise them at mains voltage via a
> > precautionary low value fuse (1 or 2 A, say). The point(s) of leakage
> > will now be injecting some current into the soil. If you're worried
> > about safety then reduce the applied voltage using a suitable
> > transformer or auto-transformer. 50 V might be enough.
> >
> > Now use a highish impedance AC voltmeter (an ordinary DMM will do) and
> > probe for ground potential gradients - i.e. earth one side of the meter
> > to a reference, the mains earth should do, via a long flying lead. On
> > the other side, rig up a probe a few inches long to stick in the ground
> > - this ought to a have an insulated handle for obvious reasons. Probe
> > around, following the cable routes, if known. Look for the highest
> > voltage and dig there.
> Nice plan...
> Might be worth adding a step of doing an additional probing before
> energising the circuit, just to establish that you are not going to be
> lead up the garden path (so to speak) by stray ground currents from
> other sources not connected with the actual circuit in question.
or use a flasher in the feed
> On 21/06/2013 23:57, Andy Wade wrote:
> > On 19/06/2013 23:36, Windmill wrote:
> > Sort of. My suggestion is as follows:
> >
> > Disconnect the feed-point from the RCD. Strap the L & N outgoing
> > conductors together and energise them at mains voltage via a
> > precautionary low value fuse (1 or 2 A, say). The point(s) of leakage
> > will now be injecting some current into the soil. If you're worried
> > about safety then reduce the applied voltage using a suitable
> > transformer or auto-transformer. 50 V might be enough.
> >
> > Now use a highish impedance AC voltmeter (an ordinary DMM will do) and
> > probe for ground potential gradients - i.e. earth one side of the meter
> > to a reference, the mains earth should do, via a long flying lead. On
> > the other side, rig up a probe a few inches long to stick in the ground
> > - this ought to a have an insulated handle for obvious reasons. Probe
> > around, following the cable routes, if known. Look for the highest
> > voltage and dig there.
> Nice plan...
> Might be worth adding a step of doing an additional probing before
> energising the circuit, just to establish that you are not going to be
> lead up the garden path (so to speak) by stray ground currents from
> other sources not connected with the actual circuit in question.
NT
John Rumm
Jun 23, 2013, 7:03:49 AM6/23/13
to
meow...@care2.com
Jun 23, 2013, 1:47:13 PM6/23/13
to
NT
Gefreiter Krueger
Jun 23, 2013, 1:50:05 PM6/23/13
to
On Tue, 18 Jun 2013 15:19:47 +0100, Richard Russell <ne...@rtrussell.co.uk> wrote:
> We have an extensive, professionally installed, garden lighting system
> which has recently started tripping its dedicated RCD. I have
> eliminated all the bulbs, luminaires and accessible cables which,
> sadly, means the problem is almost certainly in one of the many
> 'waterproof' underground connection boxes. How on earth does one
> trace a fault like this? Dig up the entire garden?
>
> Richard.
> http://www.rtrussell.co.uk/
Change it to a good old fuse. They weren't so fussy. RCDs are a pain in the arse.
> We have an extensive, professionally installed, garden lighting system
> which has recently started tripping its dedicated RCD. I have
> eliminated all the bulbs, luminaires and accessible cables which,
> sadly, means the problem is almost certainly in one of the many
> 'waterproof' underground connection boxes. How on earth does one
> trace a fault like this? Dig up the entire garden?
>
> Richard.
> http://www.rtrussell.co.uk/
--
Money can't buy you true love.
It does however put you in a good bargaining position.
ARW
Jun 23, 2013, 1:55:43 PM6/23/13
to
Gefreiter Krueger wrote:
> On Tue, 18 Jun 2013 15:19:47 +0100, Richard Russell
> <ne...@rtrussell.co.uk> wrote:
>> We have an extensive, professionally installed, garden lighting
>> system which has recently started tripping its dedicated RCD. I have
>> eliminated all the bulbs, luminaires and accessible cables which,
>> sadly, means the problem is almost certainly in one of the many
>> 'waterproof' underground connection boxes. How on earth does one
>> trace a fault like this? Dig up the entire garden?
>>
>> Richard.
>> http://www.rtrussell.co.uk/
>
> Change it to a good old fuse. They weren't so fussy.
>RCDs are a pain in the arse.
The double pole ones are.
> On Tue, 18 Jun 2013 15:19:47 +0100, Richard Russell
> <ne...@rtrussell.co.uk> wrote:
>> We have an extensive, professionally installed, garden lighting
>> system which has recently started tripping its dedicated RCD. I have
>> eliminated all the bulbs, luminaires and accessible cables which,
>> sadly, means the problem is almost certainly in one of the many
>> 'waterproof' underground connection boxes. How on earth does one
>> trace a fault like this? Dig up the entire garden?
>>
>> Richard.
>> http://www.rtrussell.co.uk/
>
> Change it to a good old fuse. They weren't so fussy.
>RCDs are a pain in the arse.
--
Adam
tony sayer
Jun 23, 2013, 1:54:32 PM6/23/13
to
In article <op.wy47t...@red.lan>, Gefreiter Krueger <n...@spam.com>
scribeth thus
the mains..
I have an I can tall you its fucking painful squared!..
If I should swear;)(
--
Tony Sayer
scribeth thus
>On Tue, 18 Jun 2013 15:19:47 +0100, Richard Russell <ne...@rtrussell.co.uk>
>wrote:
>
>> We have an extensive, professionally installed, garden lighting system
>> which has recently started tripping its dedicated RCD. I have
>> eliminated all the bulbs, luminaires and accessible cables which,
>> sadly, means the problem is almost certainly in one of the many
>> 'waterproof' underground connection boxes. How on earth does one
>> trace a fault like this? Dig up the entire garden?
>>
>> Richard.
>> http://www.rtrussell.co.uk/
>
>Change it to a good old fuse. They weren't so fussy. RCDs are a pain in the
>arse.
>
Theres speaks someone who has never been accidentally connected across
>wrote:
>
>> We have an extensive, professionally installed, garden lighting system
>> which has recently started tripping its dedicated RCD. I have
>> eliminated all the bulbs, luminaires and accessible cables which,
>> sadly, means the problem is almost certainly in one of the many
>> 'waterproof' underground connection boxes. How on earth does one
>> trace a fault like this? Dig up the entire garden?
>>
>> Richard.
>> http://www.rtrussell.co.uk/
>
>Change it to a good old fuse. They weren't so fussy. RCDs are a pain in the
>arse.
>
the mains..
I have an I can tall you its fucking painful squared!..
If I should swear;)(
--
Tony Sayer
Tim Watts
Jun 23, 2013, 2:33:23 PM6/23/13
to
On Sunday 23 June 2013 18:50 Gefreiter Krueger wrote in uk.d-i-y:
> On Tue, 18 Jun 2013 15:19:47 +0100, Richard Russell <ne...@rtrussell.co.uk>
> wrote:
>
>> We have an extensive, professionally installed, garden lighting system
>> which has recently started tripping its dedicated RCD. I have
>> eliminated all the bulbs, luminaires and accessible cables which,
>> sadly, means the problem is almost certainly in one of the many
>> 'waterproof' underground connection boxes. How on earth does one
>> trace a fault like this? Dig up the entire garden?
>>
>> Richard.
>> http://www.rtrussell.co.uk/
>
> Change it to a good old fuse. They weren't so fussy. RCDs are a pain in
> the arse.
>
Are you insane offering that as "advice" on a public group?
> On Tue, 18 Jun 2013 15:19:47 +0100, Richard Russell <ne...@rtrussell.co.uk>
> wrote:
>
>> We have an extensive, professionally installed, garden lighting system
>> which has recently started tripping its dedicated RCD. I have
>> eliminated all the bulbs, luminaires and accessible cables which,
>> sadly, means the problem is almost certainly in one of the many
>> 'waterproof' underground connection boxes. How on earth does one
>> trace a fault like this? Dig up the entire garden?
>>
>> Richard.
>> http://www.rtrussell.co.uk/
>
> Change it to a good old fuse. They weren't so fussy. RCDs are a pain in
> the arse.
>
No of course you should not dispense with an RCD, *especially* on an outside
domestic circuit.
Gefreiter Krueger
Jun 23, 2013, 2:42:33 PM6/23/13
to
--
__.------.
.-' .---. \
.' .' O )/"\/
.' ) >:' L
.'"/ ( _J: |
/ '' \ / `\ F
J ' L_( _> J
| ( ( `--' |/
J / : :. : J
| | :. :. :. : .:L
| \ . . .:'|F
| | `:. .: ||
F || ' |||
| :) : . JJ
|) | /F
V A /J
|| \_.-. .-.FF
---'--. /<--\\ L----.
|||L \|| |
JJ)) `|| |
)|___.---\----'
.--'""<'|/ |F
|J`-' FF
| L : JJ
| J :||
J | | ||
J |_/\_F
J | |J
L L ||
| | |F
| | |F
Gefreiter Krueger
Jun 23, 2013, 2:43:11 PM6/23/13
to
On Sun, 23 Jun 2013 19:33:23 +0100, Tim Watts <tw+u...@dionic.net> wrote:
> On Sunday 23 June 2013 18:50 Gefreiter Krueger wrote in uk.d-i-y:
>
>> On Tue, 18 Jun 2013 15:19:47 +0100, Richard Russell <ne...@rtrussell.co.uk>
>> wrote:
>>
>>> We have an extensive, professionally installed, garden lighting system
>>> which has recently started tripping its dedicated RCD. I have
>>> eliminated all the bulbs, luminaires and accessible cables which,
>>> sadly, means the problem is almost certainly in one of the many
>>> 'waterproof' underground connection boxes. How on earth does one
>>> trace a fault like this? Dig up the entire garden?
>>>
>>> Richard.
>>> http://www.rtrussell.co.uk/
>>
>> Change it to a good old fuse. They weren't so fussy. RCDs are a pain in
>> the arse.
>>
>
> Are you insane offering that as "advice" on a public group?
>
> No of course you should not dispense with an RCD, *especially* on an outside
> domestic circuit.
We managed just fine before RCDs were invented. Why has the world turned all girly?
> On Sunday 23 June 2013 18:50 Gefreiter Krueger wrote in uk.d-i-y:
>
>> On Tue, 18 Jun 2013 15:19:47 +0100, Richard Russell <ne...@rtrussell.co.uk>
>> wrote:
>>
>>> We have an extensive, professionally installed, garden lighting system
>>> which has recently started tripping its dedicated RCD. I have
>>> eliminated all the bulbs, luminaires and accessible cables which,
>>> sadly, means the problem is almost certainly in one of the many
>>> 'waterproof' underground connection boxes. How on earth does one
>>> trace a fault like this? Dig up the entire garden?
>>>
>>> Richard.
>>> http://www.rtrussell.co.uk/
>>
>> Change it to a good old fuse. They weren't so fussy. RCDs are a pain in
>> the arse.
>>
>
> Are you insane offering that as "advice" on a public group?
>
> No of course you should not dispense with an RCD, *especially* on an outside
> domestic circuit.
--
Question: Are there too many immigrants in Britain?
17% said yes, 11% said no, 72% said "I am not understanding the question please."
tony sayer
Jun 23, 2013, 3:01:05 PM6/23/13
to
In article <op.wy498...@red.lan>, Gefreiter Krueger <n...@spam.com>
earthed ladder and it was inside reaching out thru a window to move it a
bit sideways as it was in the way of where I was about to drill and I
can tell you if I could have fallen over I would have done anything to
"disconnect" but as your totally paralysed you cant move a bloody
thing!.
Duff house wiring that was due to and only leakage too not directly
connected but sufficient!...
--
Tony Sayer
scribeth thus
>On Sun, 23 Jun 2013 18:54:32 +0100, tony sayer <to...@bancom.co.uk> wrote:
>
>> In article <op.wy47t...@red.lan>, Gefreiter Krueger <n...@spam.com>
>> scribeth thus
>>> On Tue, 18 Jun 2013 15:19:47 +0100, Richard Russell <ne...@rtrussell.co.uk>
>>> wrote:
>>>
>>>> We have an extensive, professionally installed, garden lighting system
>>>> which has recently started tripping its dedicated RCD. I have
>>>> eliminated all the bulbs, luminaires and accessible cables which,
>>>> sadly, means the problem is almost certainly in one of the many
>>>> 'waterproof' underground connection boxes. How on earth does one
>>>> trace a fault like this? Dig up the entire garden?
>>>>
>>>> Richard.
>>>> http://www.rtrussell.co.uk/
>>>
>>> Change it to a good old fuse. They weren't so fussy. RCDs are a pain in the
>>> arse.
>>>
>> Theres speaks someone who has never been accidentally connected across
>> the mains..
>>
>> I have an I can tall you its fucking painful squared!..
>>
>> If I should swear;)(
>
>If you're connected across the mains, the RCD won't trip. You need an earth for
>that. Anyway it's only painful for a short period till you let go or fall off
>the ladder.
>
In fact it was an electric drill, metal cased in the one hand, to an
>On Sun, 23 Jun 2013 18:54:32 +0100, tony sayer <to...@bancom.co.uk> wrote:
>
>> In article <op.wy47t...@red.lan>, Gefreiter Krueger <n...@spam.com>
>> scribeth thus
>>> On Tue, 18 Jun 2013 15:19:47 +0100, Richard Russell <ne...@rtrussell.co.uk>
>>> wrote:
>>>
>>>> We have an extensive, professionally installed, garden lighting system
>>>> which has recently started tripping its dedicated RCD. I have
>>>> eliminated all the bulbs, luminaires and accessible cables which,
>>>> sadly, means the problem is almost certainly in one of the many
>>>> 'waterproof' underground connection boxes. How on earth does one
>>>> trace a fault like this? Dig up the entire garden?
>>>>
>>>> Richard.
>>>> http://www.rtrussell.co.uk/
>>>
>>> Change it to a good old fuse. They weren't so fussy. RCDs are a pain in the
>>> arse.
>>>
>> Theres speaks someone who has never been accidentally connected across
>> the mains..
>>
>> I have an I can tall you its fucking painful squared!..
>>
>> If I should swear;)(
>
>If you're connected across the mains, the RCD won't trip. You need an earth for
>that. Anyway it's only painful for a short period till you let go or fall off
>the ladder.
>
earthed ladder and it was inside reaching out thru a window to move it a
bit sideways as it was in the way of where I was about to drill and I
can tell you if I could have fallen over I would have done anything to
"disconnect" but as your totally paralysed you cant move a bloody
thing!.
Duff house wiring that was due to and only leakage too not directly
connected but sufficient!...
--
Tony Sayer
tony sayer
Jun 23, 2013, 3:02:24 PM6/23/13
to
In article <op.wy499...@red.lan>, Gefreiter Krueger <n...@spam.com>
scribeth thus
--
Tony Sayer
scribeth thus
>On Sun, 23 Jun 2013 19:33:23 +0100, Tim Watts <tw+u...@dionic.net> wrote:
>
>> On Sunday 23 June 2013 18:50 Gefreiter Krueger wrote in uk.d-i-y:
>>
>>> On Tue, 18 Jun 2013 15:19:47 +0100, Richard Russell <ne...@rtrussell.co.uk>
>>> wrote:
>>>
>>>> We have an extensive, professionally installed, garden lighting system
>>>> which has recently started tripping its dedicated RCD. I have
>>>> eliminated all the bulbs, luminaires and accessible cables which,
>>>> sadly, means the problem is almost certainly in one of the many
>>>> 'waterproof' underground connection boxes. How on earth does one
>>>> trace a fault like this? Dig up the entire garden?
>>>>
>>>> Richard.
>>>> http://www.rtrussell.co.uk/
>>>
>>> Change it to a good old fuse. They weren't so fussy. RCDs are a pain in
>>> the arse.
>>>
>>
>> Are you insane offering that as "advice" on a public group?
>>
>> No of course you should not dispense with an RCD, *especially* on an outside
>> domestic circuit.
>
>We managed just fine before RCDs were invented. Why has the world turned all
>girly?
>
Jeez!! this isn't Lootenant Pidgin who was here a while ago re incarnated?.
>
>> On Sunday 23 June 2013 18:50 Gefreiter Krueger wrote in uk.d-i-y:
>>
>>> On Tue, 18 Jun 2013 15:19:47 +0100, Richard Russell <ne...@rtrussell.co.uk>
>>> wrote:
>>>
>>>> We have an extensive, professionally installed, garden lighting system
>>>> which has recently started tripping its dedicated RCD. I have
>>>> eliminated all the bulbs, luminaires and accessible cables which,
>>>> sadly, means the problem is almost certainly in one of the many
>>>> 'waterproof' underground connection boxes. How on earth does one
>>>> trace a fault like this? Dig up the entire garden?
>>>>
>>>> Richard.
>>>> http://www.rtrussell.co.uk/
>>>
>>> Change it to a good old fuse. They weren't so fussy. RCDs are a pain in
>>> the arse.
>>>
>>
>> Are you insane offering that as "advice" on a public group?
>>
>> No of course you should not dispense with an RCD, *especially* on an outside
>> domestic circuit.
>
>We managed just fine before RCDs were invented. Why has the world turned all
>girly?
>
--
Tony Sayer
ARW
Jun 23, 2013, 3:13:56 PM6/23/13
to
Gefreiter Krueger wrote:
> On Sun, 23 Jun 2013 19:33:23 +0100, Tim Watts <tw+u...@dionic.net>
> wrote:
>> On Sunday 23 June 2013 18:50 Gefreiter Krueger wrote in uk.d-i-y:
>>
>>> On Tue, 18 Jun 2013 15:19:47 +0100, Richard Russell
>>> <ne...@rtrussell.co.uk> wrote:
>>>
>>>> We have an extensive, professionally installed, garden lighting
>>>> system which has recently started tripping its dedicated RCD. I
>>>> have eliminated all the bulbs, luminaires and accessible cables
>>>> which, sadly, means the problem is almost certainly in one of the
>>>> many 'waterproof' underground connection boxes. How on earth does
>>>> one trace a fault like this? Dig up the entire garden?
>>>>
>>>> Richard.
>>>> http://www.rtrussell.co.uk/
>>>
>>> Change it to a good old fuse. They weren't so fussy. RCDs are a
>>> pain in the arse.
>>>
>>
>> Are you insane offering that as "advice" on a public group?
>>
>> No of course you should not dispense with an RCD, *especially* on an
>> outside domestic circuit.
>
> We managed just fine before RCDs were invented. Why has the world
> turned all girly?
Suffragettes?
> On Sun, 23 Jun 2013 19:33:23 +0100, Tim Watts <tw+u...@dionic.net>
> wrote:
>> On Sunday 23 June 2013 18:50 Gefreiter Krueger wrote in uk.d-i-y:
>>
>>> On Tue, 18 Jun 2013 15:19:47 +0100, Richard Russell
>>> <ne...@rtrussell.co.uk> wrote:
>>>
>>>> We have an extensive, professionally installed, garden lighting
>>>> system which has recently started tripping its dedicated RCD. I
>>>> have eliminated all the bulbs, luminaires and accessible cables
>>>> which, sadly, means the problem is almost certainly in one of the
>>>> many 'waterproof' underground connection boxes. How on earth does
>>>> one trace a fault like this? Dig up the entire garden?
>>>>
>>>> Richard.
>>>> http://www.rtrussell.co.uk/
>>>
>>> Change it to a good old fuse. They weren't so fussy. RCDs are a
>>> pain in the arse.
>>>
>>
>> Are you insane offering that as "advice" on a public group?
>>
>> No of course you should not dispense with an RCD, *especially* on an
>> outside domestic circuit.
>
> We managed just fine before RCDs were invented. Why has the world
> turned all girly?
--
Adam
John Rumm
Jun 23, 2013, 3:21:32 PM6/23/13
to
Gefreiter Krueger
Jun 23, 2013, 3:23:00 PM6/23/13
to
--
Landing: A controlled mid-air collision with a planet.
Gefreiter Krueger
Jun 23, 2013, 3:23:23 PM6/23/13
to
Gefreiter Krueger
Jun 23, 2013, 3:25:03 PM6/23/13
to
--
When the Viagra virus comes to your PC, all your software becomes hardware.
Gefreiter Krueger
Jun 23, 2013, 3:25:10 PM6/23/13
to
--
"There are more planes in the ocean than submarines in the sky."
- From an old carrier sailor
Tim Watts
Jun 23, 2013, 3:30:49 PM6/23/13
to
On Sunday 23 June 2013 19:43 Gefreiter Krueger wrote in uk.d-i-y:
> We managed just fine before RCDs were invented. Why has the world turned
> all girly?
>
RCDs for outside leads and lawnmowers, either as fitted plugs or adaptors,
> We managed just fine before RCDs were invented. Why has the world turned
> all girly?
>
have been around since the 70's and have always be most recommended.
To come onto a public group and suggest that RCD protection be removed
because it's a bit incovenient, is uttery and grossly irresponsible.
There is a reason the current IEE/IET wiring regulations regulations require
it.
Now you are entitled to your opinion, but in these matters it is best not to
offer them to an unknown audience who might be foolish enough to follow your
advice.
Gefreiter Krueger
Jun 23, 2013, 4:29:07 PM6/23/13
to
On Sun, 23 Jun 2013 20:30:49 +0100, Tim Watts <tw+u...@dionic.net> wrote:
> On Sunday 23 June 2013 19:43 Gefreiter Krueger wrote in uk.d-i-y:
>
>> We managed just fine before RCDs were invented. Why has the world turned
>> all girly?
>
> RCDs for outside leads and lawnmowers, either as fitted plugs or adaptors,
> have been around since the 70's and have always be most recommended.
A few safety conscious pussies have yes.
> On Sunday 23 June 2013 19:43 Gefreiter Krueger wrote in uk.d-i-y:
>
>> We managed just fine before RCDs were invented. Why has the world turned
>> all girly?
>
> RCDs for outside leads and lawnmowers, either as fitted plugs or adaptors,
> have been around since the 70's and have always be most recommended.
> To come onto a public group and suggest that RCD protection be removed
> because it's a bit incovenient, is uttery and grossly irresponsible.
>
> There is a reason the current IEE/IET wiring regulations regulations require
> it.
> Now you are entitled to your opinion, but in these matters it is best not to
> offer them to an unknown audience who might be foolish enough to follow your
> advice.
--
A juggler, driving to his next performance, is stopped by the police. "What are these matches and lighter fluid doing in your car?" asks the cop.
"I'm a juggler and I juggle flaming torches in my act."
"Oh yeah?" says the doubtful cop. "Lets see you do it." The juggler gets out and starts juggling the blazing torches masterfully.
A couple driving by slows down to watch. "Wow," says the driver to his wife. "I'm glad I quit drinking. Look at the test they're giving now!"
Andy Wade
Jun 24, 2013, 7:28:10 AM6/24/13
to
(a) is there any sort of two-terminal 'flashing bulb' available that
will work into the load here - predominantly the cable capacitance in
parallel with a highish resistive leak?
(b) I suspect that the flickering display on a DMM might be difficult to
interpret, especially if other time-varying voltages are present due to
other leakages, PME diverted neutral currents, etc.
I've a better idea now: instead of injecting mains, inject an audio tone
(1 to 2 kHz, say) at as high an amplitude as you can manage. You'd need
an audio sig gen and and a power amplifier with a 100V line o/p, or a
standard amplifier plus a step-up transformer. (Do ensure that the
capacitive load and the low primary DC resistance of any transformer
don't upset the amp!)
You can now use an inherently logarithmic detector to look for the
ground leakage signal, i.e. headphones + brain. The 'cans' would need
to be high impedance (Sennheiser 414's come to mind) or used with a
suitable preamp. High-pass filtering can be used to get rid of all the
50 Hz (and its harmonics) 'noise'.
--
Andy
meow...@care2.com
Jun 27, 2013, 8:06:15 AM6/27/13
to
On Monday, June 24, 2013 12:28:10 PM UTC+1, Andy Wade wrote:
> On 23/06/2013 18:47, meow...@care2.com wrote:
> > On Sunday, June 23, 2013 12:03:49 PM UTC+1, John Rumm wrote:
> >>> or use a flasher in the feed
> >> I am sure you don't mean an old git in a rain coat, so could you elaborate?
> > :) If you pull the fuse or switch the mcb off, and clip a flashing
> > light bulb across it, you then get a mains feed that goes on and off
> > frequently. You can thus tell with your ground probe how much
> > difference the mains feed is making, it just means you can do one
> > sweep not 2. Its a classic old fashioned way to trace circuits.
> I assumed that's what you meant, but
> (a) is there any sort of two-terminal 'flashing bulb' available that
> will work into the load here - predominantly the cable capacitance in
> parallel with a highish resistive leak?
You can switch a filament lamp on to give it some load.
> On 23/06/2013 18:47, meow...@care2.com wrote:
> > On Sunday, June 23, 2013 12:03:49 PM UTC+1, John Rumm wrote:
> >>> or use a flasher in the feed
> >> I am sure you don't mean an old git in a rain coat, so could you elaborate?
> > :) If you pull the fuse or switch the mcb off, and clip a flashing
> > light bulb across it, you then get a mains feed that goes on and off
> > frequently. You can thus tell with your ground probe how much
> > difference the mains feed is making, it just means you can do one
> > sweep not 2. Its a classic old fashioned way to trace circuits.
> I assumed that's what you meant, but
> (a) is there any sort of two-terminal 'flashing bulb' available that
> will work into the load here - predominantly the cable capacitance in
> parallel with a highish resistive leak?
I havent seen thermal flashers in decades, you could probably make an equivalent using a relay though, with RC charging.
> (b) I suspect that the flickering display on a DMM might be difficult to
> interpret, especially if other time-varying voltages are present due to
> other leakages, PME diverted neutral currents, etc.
> I've a better idea now: instead of injecting mains, inject an audio tone
> (1 to 2 kHz, say) at as high an amplitude as you can manage. You'd need
> an audio sig gen and and a power amplifier with a 100V line o/p, or a
> standard amplifier plus a step-up transformer.
> (Do ensure that the
> capacitive load and the low primary DC resistance of any transformer
> don't upset the amp!)
> You can now use an inherently logarithmic detector to look for the
> ground leakage signal, i.e. headphones + brain. The 'cans' would need
> to be high impedance (Sennheiser 414's come to mind) or used with a
> suitable preamp.
> High-pass filtering can be used to get rid of all the
> 50 Hz (and its harmonics) 'noise'.
You might just use a self oscillating relay direct on the mains, with a series lamp to limit i and a 2nd parallel lamp to limit V_out to 50v max. A small relay chopping mains at 200Hz or so would get you a very different sound to 50Hz. Hi tech stuff.
NT
0 new messages