I was leaving our bedroom the other day and I was turning out the
light when I put my other hand on the CH radiator just to check if it
was warm. Big shock and tingling fingers on both hands! The
lightswitch is a stainless steel cover plate with plastic rocker
switches.

I have removed the switch from the wall to check the connections and
all looks OK, no bare wires touching anything else, and the earth wire
in the switch cable is connected to the terminal on the cover plate. I
have an old AVOmeter passed down to me by my father-in-law and a
rudimentary knowledge of how to use it. It is showing approx 230 volts
between one side of the switch terminal and the earth terminal, which
I think is to be expected.

I have gingerly tried touching the rad and the switch simultaneously
again, but I don't get a shock now.

Have I got a problem? If so, is there anything else I can do to trace
the fault and hopefully correct it?

TIA
Pete

petek wrote:

I was leaving our bedroom the other day and I was turning out the
light when I put my other hand on the CH radiator just to check if it
was warm. Big shock and tingling fingers on both hands! The
lightswitch is a stainless steel cover plate with plastic rocker
switches.

I have gingerly tried touching the rad and the switch simultaneously
again, but I don't get a shock now.

In the teaching profession, you'd be what we'd call a "slow learner".

Have I got a problem? If so, is there anything else I can do to trace
the fault and hopefully correct it?

One problem is that you're prepared to risk current from the mains
across your heart.

I'd suggest that you forbid anyone else in the house to touch either the
radiator or the lightswitch, avoid touching other radiators and metal
plumbing, and other steel switch cover plates if you can, and call an
electrician first thing tomorrow morning.

There could be any number of faults in the system (often receiving a
shock is a sign that there are indeed several faults). Consequences like
elctric shocks might only occur under a particular set of circumstances,
and some of these might not be at all obvious.

Daniele

In article
,
petek wrote:
I was leaving our bedroom the other day and I was turning out the
light when I put my other hand on the CH radiator just to check if it
was warm. Big shock and tingling fingers on both hands! The
lightswitch is a stainless steel cover plate with plastic rocker
switches.

I have removed the switch from the wall to check the connections and
all looks OK, no bare wires touching anything else, and the earth wire
in the switch cable is connected to the terminal on the cover plate. I
have an old AVOmeter passed down to me by my father-in-law and a
rudimentary knowledge of how to use it. It is showing approx 230 volts
between one side of the switch terminal and the earth terminal, which
I think is to be expected.

Should actually be 240v.

I have gingerly tried touching the rad and the switch simultaneously
again, but I don't get a shock now.

Have I got a problem? If so, is there anything else I can do to trace
the fault and hopefully correct it?

Use the AVO to measure between the switch plate and a good connection on
the rad. You should get effectively a zero reading. Make sure it's set to
AC volts. Just for information I've done the same here and get a reading -
using a high quality DVM - of 0.0027V.

Now check between the switch plate and the ring main earth. If you have
plastic sockets one of the screws should be good enough. Again, the
reading should be zero.

By this you can identify if there's a problem with that switch circuit or
the bonding elsewhere.

My guess is that the ECC in the switch wire isn't actually connected to
anything at the other end.

--
*Succeed, in spite of management *

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

On 4 Jan, 16:14, "Dave Plowman (News)" wrote:
In article
,
* *petek wrote:

I was leaving our bedroom the other day and I was turning out the
light when I put my other hand on the CH radiator just to check if it
was warm. Big shock and tingling fingers on both hands! The
lightswitch is a stainless steel cover plate with plastic rocker
switches.
I have removed the switch from the wall to check the connections and
all looks OK, no bare wires touching anything else, and the earth wire
in the switch cable is connected to the terminal on the cover plate. I
have an old AVOmeter passed down to me by my father-in-law and a
rudimentary knowledge of how to use it. It is showing approx 230 volts
between one side of the switch terminal and the earth terminal, which
I think is to be expected.

Should actually be 240v.

I have gingerly tried touching the rad and the switch simultaneously
again, but I don't get a shock now.
Have I got a problem? If so, is there anything else I can do to trace
the fault and hopefully correct it?

Use the AVO to measure between the switch plate and a good connection on
the rad. You should get effectively a zero reading. Make sure it's set to
AC volts. Just for information I've done the same here and get a reading -
using a high quality DVM - of 0.0027V.

Now check between the switch plate and the ring main earth. If you have
plastic sockets one of the screws should be good enough. Again, the
reading should be zero.

By this you can identify if there's a problem with that switch circuit or
the bonding elsewhere.

My guess is that the ECC in the switch wire isn't actually connected to
anything at the other end.

--
*Succeed, in spite of management *

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

Thanks Dave, thats been helpful so far.

I have scratched away a bit of paint on the rad and measured between
there and the switchplate. The AVO shows about 225v (I take your point
re 240v but maybe there's some local variation in mains voltage
today). So it looks indeed as though I have a fault somewhere.
Thinking about it, this would support your guess that the earth wire
is not connected at the other end.

I haven't checked between the switchplate and ring main earth at this
stage because that would mean me having to rig up some temporary
extensions to the AVO leads. The nearest socket is 3-4 mtrs away.

I suppose my next step is to trace the wiring in the loft and find out
if the earth conductor from the switch is connected to what and where.
Also while I am up there to check if a live conductor is actually
touching something it shouldn't. Any other ideas?

Pete

petek wrote:
On 4 Jan, 16:14, "Dave Plowman (News)" wrote:
In article
,
� �petek wrote:

I was leaving our bedroom the other day and I was turning out the
light when I put my other hand on the CH radiator just to check if it
was warm. Big shock and tingling fingers on both hands! The
lightswitch is a stainless steel cover plate with plastic rocker
switches.
I have removed the switch from the wall to check the connections and
all looks OK, no bare wires touching anything else, and the earth wire
in the switch cable is connected to the terminal on the cover plate. I
have an old AVOmeter passed down to me by my father-in-law and a
rudimentary knowledge of how to use it. It is showing approx 230 volts
between one side of the switch terminal and the earth terminal, which
I think is to be expected.

Should actually be 240v.

I have gingerly tried touching the rad and the switch simultaneously
again, but I don't get a shock now.
Have I got a problem? If so, is there anything else I can do to trace
the fault and hopefully correct it?

Use the AVO to measure between the switch plate and a good connection on
the rad. You should get effectively a zero reading. Make sure it's set to
AC volts. Just for information I've done the same here and get a reading -
using a high quality DVM - of 0.0027V.

Now check between the switch plate and the ring main earth. If you have
plastic sockets one of the screws should be good enough. Again, the
reading should be zero.

By this you can identify if there's a problem with that switch circuit or
the bonding elsewhere.

My guess is that the ECC in the switch wire isn't actually connected to
anything at the other end.

--
*Succeed, in spite of management *

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

Thanks Dave, thats been helpful so far.

I have scratched away a bit of paint on the rad and measured between
there and the switchplate. The AVO shows about 225v (I take your point
re 240v but maybe there's some local variation in mains voltage
today). So it looks indeed as though I have a fault somewhere.
Thinking about it, this would support your guess that the earth wire
is not connected at the other end.

I haven't checked between the switchplate and ring main earth at this
stage because that would mean me having to rig up some temporary
extensions to the AVO leads. The nearest socket is 3-4 mtrs away.

I suppose my next step is to trace the wiring in the loft and find out
if the earth conductor from the switch is connected to what and where.
Also while I am up there to check if a live conductor is actually
touching something it shouldn't. Any other ideas?

Pete

your next step is to test from rad to a reliable earth, and from light
switch to reliable earth, to find out which one's live. Then report
back, if still alive.


NT

On 4 Jan, 17:13, wrote:
petek wrote:
On 4 Jan, 16:14, "Dave Plowman (News)" wrote:
In article
,
petek wrote:

I was leaving our bedroom the other day and I was turning out the
light when I put my other hand on the CH radiator just to check if it
was warm. Big shock and tingling fingers on both hands! The
lightswitch is a stainless steel cover plate with plastic rocker
switches.
I have removed the switch from the wall to check the connections and
all looks OK, no bare wires touching anything else, and the earth wire
in the switch cable is connected to the terminal on the cover plate. I
have an old AVOmeter passed down to me by my father-in-law and a
rudimentary knowledge of how to use it. It is showing approx 230 volts
between one side of the switch terminal and the earth terminal, which
I think is to be expected.

Should actually be 240v.

I have gingerly tried touching the rad and the switch simultaneously
again, but I don't get a shock now.
Have I got a problem? If so, is there anything else I can do to trace
the fault and hopefully correct it?

Use the AVO to measure between the switch plate and a good connection on
the rad. You should get effectively a zero reading. Make sure it's set to
AC volts. Just for information I've done the same here and get a reading -
using a high quality DVM - of 0.0027V.

Now check between the switch plate and the ring main earth. If you have
plastic sockets one of the screws should be good enough. Again, the
reading should be zero.

By this you can identify if there's a problem with that switch circuit or
the bonding elsewhere.

My guess is that the ECC in the switch wire isn't actually connected to
anything at the other end.

--
*Succeed, in spite of management *

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

Thanks Dave, thats been helpful so far.

I have scratched away a bit of paint on the rad and measured between
there and the switchplate. The AVO shows about 225v (I take your point
re 240v but maybe there's some local variation in mains voltage
today). So it looks indeed as though I have a fault somewhere.
Thinking about it, this would support your guess that the earth wire
is not connected at the other end.

I haven't checked between the switchplate and ring main earth at this
stage because that would mean me having to rig up some temporary
extensions to the AVO leads. The nearest socket is 3-4 mtrs away.

I suppose my next step is to trace the wiring in the loft and find out
if the earth conductor from the switch is connected to what and where.
Also while I am up there to check if a live conductor is actually
touching something it shouldn't. Any other ideas?

Pete

your next step is to test from rad to a reliable earth, and from light
switch to reliable earth, to find out which one's live. Then report
back, if still alive.

NT- Hide quoted text -

- Show quoted text -

OK, I've not been in the loft yet, but have done some more testing as
NT suggested and I'm still alive, but getting more worried!

There's no voltage showing between the rad and nearby ringmain earth
(I assume a "reliable earth"). The resistance between the rad and ring
main earth is only 1 or 2 ohms, so this suggests the rad is earthed
OK, I think.

There's a voltage of 225v approx showing between switchplate and
ringmain earth, which is in line with previous tests i.e. 225v between
switchplate and rad, and very little resistance between rad and
ringmain earth. There is a high resistance (i.e. no needle movement on
the AVO) between rad and switchplate

So, this looks to me as though the switchplate is indeed live, and the
earth conductor in the switch cable is not connected at the other end
(as Dave guessed). Up to the loft I go .........

Pete

On Sun, 4 Jan 2009 09:37:46 -0800 (PST), petek
wrote:

here's a voltage of 225v approx showing between switchplate and
ringmain earth, which is in line with previous tests i.e. 225v between
switchplate and rad, and very little resistance between rad and
ringmain earth. There is a high resistance (i.e. no needle movement on
the AVO) between rad and switchplate
Ouch - 225VAC across the poor avo's resistance range...

--
Geo

wrote:

I have gingerly tried touching the rad and the switch simultaneously
again, but I don't get a shock now.
Have I got a problem? If so, is there anything else I can do to trace
the fault and hopefully correct it?

I have scratched away a bit of paint on the rad and measured between
there and the switchplate. The AVO shows about 225v (I take your point
re 240v but maybe there's some local variation in mains voltage
today). So it looks indeed as though I have a fault somewhere.
Thinking about it, this would support your guess that the earth wire
is not connected at the other end.

I haven't checked between the switchplate and ring main earth at this
stage because that would mean me having to rig up some temporary
extensions to the AVO leads. The nearest socket is 3-4 mtrs away.

I suppose my next step is to trace the wiring in the loft and find out
if the earth conductor from the switch is connected to what and where.
Also while I am up there to check if a live conductor is actually
touching something it shouldn't. Any other ideas?

your next step is to test from rad to a reliable earth, and from light
switch to reliable earth, to find out which one's live. Then report
back, if still alive.

I'm somewhat surprised that having reported receiving a "big shock" from
alight switch and radiator, no-one else is advising more caution to
someone who doesn't seem to have very much expertise.

Let's assume that it wasn't just a big electrostatic discharge (most
people can tell the difference). The most likely cause is an earth that
has gone live, and the switch plate with it. What else should be earthed
but might now be live?

I've discovered, on more than one occasion, DIY electrical work that was
ready to kill, including the (supposed) earth in lighting circuits that
was in fact switched live.

My guess is that the ECC in the switch wire isn't actually connected to
anything at the other end.

That would still require a second fault, to give someone a big shock
just by touching the switch plate. The earth circuit is to offer
protection against such faults. So Pete's dealing with a circuit with a
fault, and faulty protection.

Daniele

Daniele

In article
,
D.M. Procida wrote:
I've discovered, on more than one occasion, DIY electrical work that was
ready to kill, including the (supposed) earth in lighting circuits that
was in fact switched live.

I've seen that done by pros. Big reputable firm too.

My guess is that the ECC in the switch wire isn't actually connected
to anything at the other end.

That would still require a second fault, to give someone a big shock
just by touching the switch plate. The earth circuit is to offer
protection against such faults. So Pete's dealing with a circuit with a
fault, and faulty protection.

Capacitive coupling can easily cause a tingle. The earth wire not actually
connected can give this effect. The OP has already proved it's not
connected so is halfway there to sorting it. However, it might well be a
bigger job than he imagines - there might not be any ECC connection on the
lighting circuits, and never has been.

--
*Change is inevitable, except from a vending machine.

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

On 4 Jan, 17:43, (D.M.
Procida) wrote:
wrote:
I have gingerly tried touching the rad and the switch simultaneously
again, but I don't get a shock now.
Have I got a problem? If so, is there anything else I can do to trace
the fault and hopefully correct it?
I have scratched away a bit of paint on the rad and measured between
there and the switchplate. The AVO shows about 225v (I take your point
re 240v but maybe there's some local variation in mains voltage
today). So it looks indeed as though I have a fault somewhere.
Thinking about it, this would support your guess that the earth wire
is not connected at the other end.

I haven't checked between the switchplate and ring main earth at this
stage because that would mean me having to rig up some temporary
extensions to the AVO leads. The nearest socket is 3-4 mtrs away.

I suppose my next step is to trace the wiring in the loft and find out
if the earth conductor from the switch is connected to what and where.
Also while I am up there to check if a live conductor is actually
touching something it shouldn't. Any other ideas?
your next step is to test from rad to a reliable earth, and from light
switch to reliable earth, to find out which one's live. Then report
back, if still alive.

I'm somewhat surprised that having reported receiving a "big shock" from
alight switch and radiator, no-one else is advising more caution to
someone who doesn't seem to have very much expertise.

Let's assume that it wasn't just a big electrostatic discharge (most
people can tell the difference). The most likely cause is an earth that
has gone live, and the switch plate with it. What else should be earthed
but might now be live?

I've discovered, on more than one occasion, DIY electrical work that was
ready to kill, including the (supposed) earth in lighting circuits that
was in fact switched live.

My guess is that the ECC in the switch wire isn't actually connected to
anything at the other end.

That would still require a second fault, to give someone a big shock
just by touching the switch plate. The earth circuit is to offer
protection against such faults. So Pete's dealing with a circuit with a
fault, and faulty protection.

Daniele

Daniele- Hide quoted text -

- Show quoted text -

OK Daniele, thanks for your concerns which are much appreciated. Just
to set the record straight in terms of my expertise. I have a BSc Hons
in Mechanical Engineering (which included some electrical/electronic
theory) albeit 40 years ago, and reasonable experience of simple DIY
electrics but I admit I am not up to scratch with capacitive coupling
and leakage impedance although the terms are a bit familiar from 40
years ago.

I have experienced static shocks many times previously and this felt
more like a mains shock (which I have also experienced in the past!)

To reply to John, my AVO is a Model 8 and I have been using the 300Vac
range (there isn't a 250Vac range).

My excursion up to the loft has revealed nothing untoward visually in
terms of electrical connections, i.e. no bare wires or loose
connections, but there may be a problem with the connection of the
switch cable earth conductor at the ceiling rose. I can't check this
properly as it will mean moving the bed to get at it and I don't want
to start doing this on a Sunday evening. I may have a go tomorrow. If
indeed this is faulty then it would support the theory that the
stainless steel switchplate is not effectively earthed.

There also appears to be a break in the lighting ring earth between
this bedroom light and the next light in the circuit, where a spur has
been taken off using a junction box and the earth wire not continued
IYSWIM.

Which leaves me with the conclusion that the earth circuit is not
100%, and that there is a fault somewhere that is making the
switchplate live. But how to trace this fault........?

Think it's time to bite the bullet, get a leccy in and take out a
second mortgage to pay him!

Pete

D.M. Procida wrote:

Pete's dealing with a circuit with a fault, and faulty protection.

It's all gone silent since Sunday night. I hope that the first visit
Pete had on Monday morning was the electrician, and not the paramedics.

Daniele

I suppose my next step is to trace the wiring in the loft and find out
if the earth conductor from the switch is connected to what and where.
Also while I am up there to check if a live conductor is actually
touching something it shouldn't. Any other ideas?


You could get a fairly unpleasant shock just from capacitive coupling
between the live and floating earth conductors without any direct
connection between them. However, if you were using your AVO (I am
assuming a model 8) on the 250Vac range, it was drawing nearly 1mA
while causing the supply voltage to be attenuated by perhaps 10V to
20V.

Assuming that the leakage impedance is constant, this implies a
potential leakage current of perhaps 5 to 10 mA into a low impedance
which is a lot for capacitive coupling in your lighting circuit.

Your whole house might have a floating earth connection, in which case
you felt the combined leakage currents of whatever appliances were
switched on.

If you repeat your measurement on the 250V and 1000V ac ranges in
quick succession and also measure the mains voltage the leakage
current can be calculated much more accurately. (Don't be tempted to
use a current range on the AVO - you risk destroying it and possibly
hurting yourself.)

Check that there is proper cross bonding between gas and water pipes
and the main electrical supply earth as a matter of urgency. The
leakage current could become a lot higher if an electric oven or
immersion heater is switched on.

John

In article
,
petek wrote:
I have scratched away a bit of paint on the rad and measured between
there and the switchplate. The AVO shows about 225v (I take your point
re 240v but maybe there's some local variation in mains voltage
today). So it looks indeed as though I have a fault somewhere.

You have indeed.

Thinking about it, this would support your guess that the earth wire
is not connected at the other end.

Only a guess - do the other checks first.

I haven't checked between the switchplate and ring main earth at this
stage because that would mean me having to rig up some temporary
extensions to the AVO leads. The nearest socket is 3-4 mtrs away.

Have you got something you know to be earthed - perhaps a metal kettle
etc? Use that to measure to - it only needs to be plugged in, not switched
on.

I suppose my next step is to trace the wiring in the loft and find out
if the earth conductor from the switch is connected to what and where.

The first step (after doing the tests) is to examine the earth bonding
where the services enter the house. If it's not present or faulty this
should be seen to before anything else.


Also while I am up there to check if a live conductor is actually
touching something it shouldn't. Any other ideas?

--
*Hard work has a future payoff. Laziness pays off NOW.

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

In message , "Dave Plowman (News)"
writes
Should actually be 240v.
Should it? Didn't we 'harmonise' with Yoorope on 230V a few years back
or have I mis remembered that?


--
Clint Sharp

In article ,
Clint Sharp wrote:
In message , "Dave Plowman (News)"
writes
Should actually be 240v.

Should it? Didn't we 'harmonise' with Yoorope on 230V a few years back
or have I mis remembered that?

We just changed the tolerance to conform with Europe. The actual voltage
is still nominally 240.

--
*Why is 'abbreviation' such a long word?

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

On Sun, 4 Jan 2009 21:07:26 +0000, Clint Sharp wrote:

In message , "Dave Plowman (News)"
writes

Should actually be 240v.

Should it? Didn't we 'harmonise' with Yoorope on 230V a few years back
or have I mis remembered that?

You haven't mis remembered and the nominal voltage in the UK is now 230v.
But they played with the tolerances such that nothing had to actually
change. IIRC it was 240v +/-6% (225 - 254v) it's now 230v +10% -6% (216 -
253v), There was talk of altering the tolerance to +/-10% but that seems
to have been forgotten, just as well 207 to 253v is one helluva range for
kit to deal with.

--
Cheers
Dave.

On 4 Jan, 16:14, "Dave Plowman (News)" wrote:
In article
,
petek wrote:

It is showing approx 230 volts
between one side of the switch terminal and the earth terminal, which
I think is to be expected.

Should actually be 240v.

Why? We went to 230V years ago. Or are you expecting a -10V earth?

Ian

The Real Doctor wrote:
On 4 Jan, 16:14, "Dave Plowman (News)" wrote:
In article
,
petek wrote:

It is showing approx 230 volts
between one side of the switch terminal and the earth terminal, which
I think is to be expected.
Should actually be 240v.

Why? We went to 230V years ago. Or are you expecting a -10V earth?


Ah but its a Nu Laber 230v, like the crime rate. Its *specified* lower
because we were always 240v, so its 230v +5%..;-)


Ian

On Jan 9, 1:52 pm, The Real Doctor wrote:
On 4 Jan, 16:14, "Dave Plowman (News)" wrote:

In article
,
petek wrote:
It is showing approx 230 volts
between one side of the switch terminal and the earth terminal, which
I think is to be expected.

Should actually be 240v.

Why? We went to 230V years ago. Or are you expecting a -10V earth?

No we didn't. The standard is now 230V +10% / -6% - but the CEGB
still tends to push out 240V +/- 6% (which happens to be towards the
top end of that range).

On 9 Jan, 20:21, wrote:
On 9 Jan, *
* * *Martin Bonner wrote:

No we didn't. *The standard is now 230V +10% / -6% - but the CEGB
still tends to push out 240V +/- 6% (which happens to be towards the
top end of that range).

Mine's rarely above 234, currently 225 but it never has been any higher.
We're far from the sub station. when we used incandescents they rarely
failed.

At the previous house we were very close to the SS. We had a good stock of
bulbs when we moved in, but in a year they had all blown. IIRC we were nearer
250v there.

--
* B Thumbs
* Change lycos to yahoo to reply

Just to bring this post to a conclusion I thought I would update you
all on the outcome.

The fault was eventually traced to a nail fixing the skirting on the
upstairs landing which had been hammered through the 3core+earth cable
used as strappers for the 2-way light on the stairs. The nail was
touching the bare earth wire and had penetrated the insulation on the
blue wire. This must have been done when the house was built in 1979
as no other work has ever been done in this area (we've lived here
since the house was new). It was a devil of a job finding the fault.
We had to isolate every light on the circuit by disconnecting the
live, neutral and earth wires at each rose and switch, and testing
each one individually. Sod's law applied as the staircase light was
the last but one on the circuit and hence the last but one to be
tested. I then had to cut a section of chipboard floor out for access,
and cut a chase in the landing wall to get the defective cable out,
and install a new length.

The earth wire in first section of the upstairs lighting circuit (i.e.
between the CU and the first light) had been cut back at both ends and
not connected either at the CU or at the ceiling rose of the light. So
even though all the other earth wires in the circuit were connected,
the earth was effectively non-existant. I strongly suspect this was
done deliberately when the house was first built in order to conceal
the short circuit as the leccy at the time probably couldn't be
bothered tracing the fault. We have upgraded the CU from old style
wired fuses to a RCD/MCB type and ensured that all earths are properly
connected.

I have taken a chance on the Part P thing, and used the leccy I
originally got in (who was a JIB Approved Electrician if you remember
from my previous posts). He seemed to me very competent, and welcomed
me acting as his "apprentice/assistant". Total cost was £275 (£210 for
the CU and £65 for tracing and fixing the faulty cable) which included
materials and 11 - 12 hours labour over 2 days (most of the labour
time was tracing the fault).

Thanks again for all your constructive comments. It really does help
being part of this group and I enjoy participating immensely.

Pete

petek wrote:

Thanks again for all your constructive comments. It really does help
being part of this group and I enjoy participating immensely.

Thanks for the update Pete. It's nice to know the eventual outcome of
these things.

--
Cheers,

John.

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

In article
,
The Real Doctor wrote:
It is showing approx 230 volts
between one side of the switch terminal and the earth terminal, which
I think is to be expected.

Should actually be 240v.

Why? We went to 230V years ago.

No we didn't. The actual voltage hasn't changed. Only the spec.

--


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

In an earlier contribution to this discussion,
petek wrote:

I was leaving our bedroom the other day and I was turning out the
light when I put my other hand on the CH radiator just to check if it
was warm. Big shock and tingling fingers on both hands! The
lightswitch is a stainless steel cover plate with plastic rocker
switches.

I have removed the switch from the wall to check the connections and
all looks OK, no bare wires touching anything else, and the earth wire
in the switch cable is connected to the terminal on the cover plate. I
have an old AVOmeter passed down to me by my father-in-law and a
rudimentary knowledge of how to use it. It is showing approx 230 volts
between one side of the switch terminal and the earth terminal, which
I think is to be expected.

I have gingerly tried touching the rad and the switch simultaneously
again, but I don't get a shock now.

Have I got a problem? If so, is there anything else I can do to trace
the fault and hopefully correct it?

TIA
Pete

It needs checking out, as others have said.

However, my guess is that you'd somehow managed to aquire an electrostatic
charge, which discharged - giving you a tingle - when you touched the
radiator and switch. The same thing would probably have happened had you
touched only one of them. In this cold weather, the humidity is very low,
and it's easy to build up quite a charge - especially if your carpets and/or
clothes contain nylon.
--
Cheers,
Roger
______
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"Roger Mills" wrote in message
...
In an earlier contribution to this discussion,
petek wrote:

I was leaving our bedroom the other day and I was turning out the
light when I put my other hand on the CH radiator just to check if it
was warm. Big shock and tingling fingers on both hands! The
lightswitch is a stainless steel cover plate with plastic rocker
switches.

I have removed the switch from the wall to check the connections and
all looks OK, no bare wires touching anything else, and the earth wire
in the switch cable is connected to the terminal on the cover plate. I
have an old AVOmeter passed down to me by my father-in-law and a
rudimentary knowledge of how to use it. It is showing approx 230 volts
between one side of the switch terminal and the earth terminal, which
I think is to be expected.

I have gingerly tried touching the rad and the switch simultaneously
again, but I don't get a shock now.

Have I got a problem? If so, is there anything else I can do to trace
the fault and hopefully correct it?

TIA
Pete

It needs checking out, as others have said.

However, my guess is that you'd somehow managed to aquire an electrostatic
charge, which discharged - giving you a tingle - when you touched the
radiator and switch. The same thing would probably have happened had you
touched only one of them. In this cold weather, the humidity is very low,
and it's easy to build up quite a charge - especially if your carpets
and/or clothes contain nylon.

He was seeing 230V between the metal clad lightswitch and the
radiator on a 20,000 ohms per volt meter. That's_ not_static

--
Graham.

%Profound_observation%

On Sun, 4 Jan 2009 18:49:54 -0000, "Graham." wrote:



"Roger Mills" wrote in message
...
In an earlier contribution to this discussion,
petek wrote:

I was leaving our bedroom the other day and I was turning out the
light when I put my other hand on the CH radiator just to check if it
was warm. Big shock and tingling fingers on both hands! The
lightswitch is a stainless steel cover plate with plastic rocker
switches.

I have removed the switch from the wall to check the connections and
all looks OK, no bare wires touching anything else, and the earth wire
in the switch cable is connected to the terminal on the cover plate. I
have an old AVOmeter passed down to me by my father-in-law and a
rudimentary knowledge of how to use it. It is showing approx 230 volts
between one side of the switch terminal and the earth terminal, which
I think is to be expected.

I have gingerly tried touching the rad and the switch simultaneously
again, but I don't get a shock now.

Have I got a problem? If so, is there anything else I can do to trace
the fault and hopefully correct it?

TIA
Pete

It needs checking out, as others have said.

However, my guess is that you'd somehow managed to aquire an electrostatic
charge, which discharged - giving you a tingle - when you touched the
radiator and switch. The same thing would probably have happened had you
touched only one of them. In this cold weather, the humidity is very low,
and it's easy to build up quite a charge - especially if your carpets
and/or clothes contain nylon.

He was seeing 230V between the metal clad lightswitch and the
radiator on a 20,000 ohms per volt meter. That's_ not_static

It's the potential between live and an earth. Pretty much what one
would expect

I'd question the carpets.

if you want the carpets to talk you might have to beat them!

[g]

george (dicegeorge) wrote:
I'd question the carpets.

if you want the carpets to talk you might have to beat them!

[g]

depends what he's been taking...


NT

on 04/01/2009, petek supposed :
I was leaving our bedroom the other day and I was turning out the
light when I put my other hand on the CH radiator just to check if it
was warm. Big shock and tingling fingers on both hands! The
lightswitch is a stainless steel cover plate with plastic rocker
switches.

I have removed the switch from the wall to check the connections and
all looks OK, no bare wires touching anything else, and the earth wire
in the switch cable is connected to the terminal on the cover plate. I
have an old AVOmeter passed down to me by my father-in-law and a
rudimentary knowledge of how to use it. It is showing approx 230 volts
between one side of the switch terminal and the earth terminal, which
I think is to be expected.

I have gingerly tried touching the rad and the switch simultaneously
again, but I don't get a shock now.

Have I got a problem? If so, is there anything else I can do to trace
the fault and hopefully correct it?

Your reading with the meter are correct, but that is not the way to be
certain it is properly earthed. Assumming everything is correct with
the switch, the other possibility (unlikely) is that the radiator
became briefly live.

Sometimes a nerve in your body catches and it can certainly seem like a
large jolt.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk