Hello all,

A friend of mine has just (Yesterday) had a hot tub installed at his house,
in the garden.

All seems to work fine.

However, We (I) just (out of curiosity) put one probe of a multimeter in the
water and the other one into the grass next to the tub.

I got a reading of about 35v AC @ 0.12mA between the two.

We can't feel any shocks etc. from the water (with bare feet on the (wet!)
grass)

His earthing is provided by the armour of the main feed to the house.

He has about 3m of 2.5mm T&E from the house CU to a plastic box, then about
15m of 2.5mm armoured cable between there and the CU in the shed (Three
core, using one core for the earth), then from a 20A MCB, a FCU with a 13A
fuse (Via about 40cms of 2.5mm T&E) then from there (Via a metal box) 2m of
2.5mm armoured cable (Three core, using one core for the earth) to a triple
pole isolator near the tub (like this)
http://www.tlc-direct.co.uk/Products/CMDX020.html
Then from there, about 4m of 2.5mm armoured cable (Three core, using one
core for the earth) to the tub.

It is protected by two 30mA RCD's (One in the house, then a second one in a
consumer unit in the shed next to the tub)

We are not getting any RCD tripping.

Is it just because this path to earth is favoured slightly, as it is a
shorter distance than via the main supply armour? - If so, should we install
an earth rod from the shed consumer unit, but leave the house earth
connected too? (This seems the logical thing to do in my mind) If so, would
10mm cable between the CU and the rod be the right choice?

Any advice would be gladly received!

--

Sparks...
(Not an electrician!)

Sparks wrote:

Hello all,

A friend of mine has just (Yesterday) had a hot tub installed at his house,
in the garden.

All seems to work fine.

However, We (I) just (out of curiosity) put one probe of a multimeter in the
water and the other one into the grass next to the tub.

I got a reading of about 35v AC @ 0.12mA between the two.

Kill the power to it immediately. Something serious is wrong.


NT

The message . com
from contains these words:

Kill the power to it immediately. Something serious is wrong.

Probably because the earth has been exported to some way from where it's
actually earthed.

--
Skipweasel
Pay no attention to that man behind the curtain.

"Guy King" wrote in message
...
The message . com
from contains these words:

Kill the power to it immediately. Something serious is wrong.

Probably because the earth has been exported to some way from where it's
actually earthed.

--
Skipweasel
Pay no attention to that man behind the curtain.

That is what I was thinking, I assume the earth supplied by the power
company is actually connected to planet earth at the substation, this, I
assume, is quite a way away from the house, so some current is flowing to
planet earth via the shorter route. So the solution is to install an earth
rod near the tub?

Sparks...

Sparks wrote:
"Guy King" wrote in message
...
The message . com
from contains these words:

Kill the power to it immediately. Something serious is wrong.
Probably because the earth has been exported to some way from where it's
actually earthed.

--
Skipweasel
Pay no attention to that man behind the curtain.

That is what I was thinking, I assume the earth supplied by the power
company is actually connected to planet earth at the substation, this, I
assume, is quite a way away from the house, so some current is flowing to
planet earth via the shorter route. So the solution is to install an earth
rod near the tub?


Possibly.

In my installation here, with a substation (sic!) in the garden. My own
very own substation (did you want 3 phase with that, sir?)..the outer
sheath of the underground cable I had to lay is neutral AND ground both.
I assume they connected that to teh frame of teh equipment in the cabinet.

That leaves a potential (sic!) way for local house earth to be very
different, if large currents flow, so I ran a bloody thick cable to an
earth rod whacked 5 ft into the wet clay, from the consumer unit
area...I am not sure whether or not the outer of the incoming is
connected to earth somehow or not...I suspect we left it as neutral only.

I managed to not destroy a valve radio once that some cheerful co
apprentices had wired up with the loudspeaker across the mains, because
it hummed as soon as it was plugged in, (but not switched on) a meter
revealed that there was 15v AC between neutral and earth..and they had
missed the fact that they had connected the switched live to the EARTHED
side of the loudspeaker..and the neutral to the 'hot' side of it.

What teh effects of this crass vandalism would have been I do not know.

I had the satisfaction of getting out my soldering iron and removing all
the b'modifications' , and turning it up to 11....;-)






Sparks...

The message
from "Sparks" contains these words:

That is what I was thinking, I assume the earth supplied by the power
company is actually connected to planet earth at the substation, this, I
assume, is quite a way away from the house, so some current is flowing to
planet earth via the shorter route. So the solution is to install an earth
rod near the tub?

That'd depend on which earth system is in use. In our house there's a
tag beside the incoming cable which says which sort of earth it's got.
There are several.

--
Skipweasel
Pay no attention to that man behind the curtain.

Guy King wrote:
The message . com
from contains these words:

Kill the power to it immediately. Something serious is wrong.

Probably because the earth has been exported to some way from where it's
actually earthed.

That could explain 3.5v but not 35v.

NT

That could explain 3.5v but not 35v.


Is it not possible that the water itself is acting as a
weak electrolyte and that is where the REAL voltage
being read is coming from? I.e .it's nothing to do
with the mains.

Easy to test for this. Just totally disconnect ALL
wiring to the mains and see if the reading is still
there.

Just Another DIY Fan wrote:
That could explain 3.5v but not 35v.


Is it not possible that the water itself is acting as a
weak electrolyte and that is where the REAL voltage
being read is coming from? I.e .it's nothing to do
with the mains.

Easy to test for this. Just totally disconnect ALL
wiring to the mains and see if the reading is still
there.

electrolytic action would supply a DC current and not AC I would have
thought.

The message .com
from "Just Another DIY Fan" contains these words:

Is it not possible that the water itself is acting as a
weak electrolyte and that is where the REAL voltage
being read is coming from? I.e .it's nothing to do
with the mains.

If you can find an electrochemical pair that can make 35 volts with a
single cell you're going to be rich beyond the dreams of avarice!

--
Skipweasel
Pay no attention to that man behind the curtain.

Guy King wrote:
The message .com
from "Just Another DIY Fan" contains these words:

Is it not possible that the water itself is acting as a
weak electrolyte and that is where the REAL voltage
being read is coming from? I.e .it's nothing to do
with the mains.

If you can find an electrochemical pair that can make 35 volts with a
single cell you're going to be rich beyond the dreams of avarice!

Possibly, but more likely from pyrotechnics than battery manufacture.
The higher the cell voltage, the faster things fry up. Cells of 4v or
so are usually over in seconds, so 35v would be a firework or bomb.

And an ac cell would certainly interest everyone


NT

wrote:

If you can find an electrochemical pair that can make 35 volts with a
single cell you're going to be rich beyond the dreams of avarice!

True but it would be interesting to know how the extremely low current
was measured as well before saying that the meter was displaying the
truth. Many digital meters display all sorts of rubbish under adverse
conditions.

It would be interesting to put a frequency counter or a 'scope in place

to see if it was indeed 50 Hertz mains ac. It could even be picking up
stray rf.

Just Another DIY Fan wrote:
wrote:

If you can find an electrochemical pair that can make 35 volts with a
single cell you're going to be rich beyond the dreams of avarice!

True but it would be interesting to know how the extremely low current
was measured as well before saying that the meter was displaying the
truth. Many digital meters display all sorts of rubbish under adverse
conditions.

It would be interesting to put a frequency counter or a 'scope in place

to see if it was indeed 50 Hertz mains ac. It could even be picking up
stray rf

".It could even be picking up
stray rf."

At 35v !! that would be some new kind of power transmission, needs to
be marketed, overhead cables will be no more !!! :-)

The message . com
from "Staffbull" contains these words:

".It could even be picking up
stray rf."

At 35v !! that would be some new kind of power transmission, needs to
be marketed, overhead cables will be no more !!! :-)

Wasn't it Tesla who wanted to transmit power by RF?

--
Skipweasel
Pay no attention to that man behind the curtain.

Guy King wrote:
The message . com
from "Staffbull" contains these words:

".It could even be picking up
stray rf."

At 35v !! that would be some new kind of power transmission, needs to
be marketed, overhead cables will be no more !!! :-)

Wasn't it Tesla who wanted to transmit power by RF?

--
Skipweasel
Pay no attention to that man behind the curtain.

Tesla coils, yes. Transmitted across small distances as the air breaks
down, lightning does it fairly well over greater distances!! not the
safest option for power transmission me thinks :-)

Be a nice option though, would save me having to channel the cables in
the extension :-)

Staffbull wrote:

Be a nice option though, would save me having to channel the cables in
the extension :-)

Dunno if anyone still does it but years ago was experiments with
transmitting power through ground itself.

Just Another DIY Fan wrote:
someone else wrote:

If you can find an electrochemical pair that can make 35 volts with a
single cell you're going to be rich beyond the dreams of avarice!

True but it would be interesting to know how the extremely low current
was measured as well before saying that the meter was displaying the
truth. Many digital meters display all sorts of rubbish under adverse
conditions.

in this case its displaying correct, as the source is low impedance.

It would be interesting to put a frequency counter or a 'scope in place

to see if it was indeed 50 Hertz mains ac. It could even be picking up
stray rf.

It probably is, but that will contribute only microvolts. Unless
someone's hidden 3 car batteries under there and put them in the earth
lead, its mains. And whats worse there are 2 dangerous faults. First
mains is flowing through the water due to bad insulaiton or wrong
wiring, and 2nd the thing isnt earthed. Whoever wired it up should kill
themselves by using it.


NT

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Guy King
saying something like:

Is it not possible that the water itself is acting as a
weak electrolyte and that is where the REAL voltage
being read is coming from? I.e .it's nothing to do
with the mains.

If you can find an electrochemical pair that can make 35 volts with a
single cell you're going to be rich beyond the dreams of avarice!

The Soap and FartGas Cell?
--

Dave

The message
from Grimly Curmudgeon contains these words:

If you can find an electrochemical pair that can make 35 volts with a
single cell you're going to be rich beyond the dreams of avarice!

The Soap and FartGas Cell?

Hmmm, methane fuel-cells. Won't the sulphur contamination poison the
cell like it does the rest of us?

--
Skipweasel
Pay no attention to that man behind the curtain.

Sparks wrote:

A friend of mine has just (Yesterday) had a hot tub installed at his house,
in the garden.

In the open, or in some kind of outbuilding? What is the 'flooring'
adjacent to the bath? Form later comments it does sound as it it's in
the open.

All seems to work fine.

However, We (I) just (out of curiosity) put one probe of a multimeter in the
water and the other one into the grass next to the tub.

I got a reading of about 35v AC @ 0.12mA between the two.

Presumably you mean 35 V open-circuit voltage (meter on volts) and 0.12
mA short-circuit current (meter on mA). The latter reading is pretty
meaningless with the short meter probes just stuck into the water and
ground. Repeat the test between the metalwork of the bath (presumably
earthed to the exported house earth) and a more substantial electrode in
the ground - a 2 ft. offcut of 15 mm copper water pipe is handy for this.

His earthing is provided by the armour of the main feed to the house.

And the house earthing system is what? TN-S, TN-C-S (PME) or TT? 35 V
is quite a high difference between a supplier's mains earth and the
local ground these days, with their multiply-earthed networks - but it
clearly can occur. What's more to the point is that it might only take
one fault in the network to turn that 35 V into 230 V and that would
make getting in and out of the bath rather dangerous...

In fact the whole installation sounds quite dangerous. An exported
mains earth (probably TN) into an outdoor situation and no attempt to
make an equipotential zone around the tub. And the two 30 mA RCDs in
cascade, no discrimination between them, sends out a message about the
lack of competence of the installer.

To use an exported TN earth in this situation the very least I would
have suggested is that there must be a bonded metal grid under the tub
and immediate surroundings, and the bonding should meet the requirements
for a main bonding conductor (min. 6mm^2 for TN-S or 10 for PME). Bits
of 2.5 T&E (with 1.5 mm^2 earths) just aren't up to the job here.

The practical fix is to convert this to a local TT system. Isolate and
insulate the exported earth at the outdoor end of the cable and provide
a local earth system to which the tub and all its ancillaries should be
earthed, via a local main earth terminal. The local earth system
should consist of an adequate rod electrode (probably 8 ft.) and the
aforesaid mat or grid under the tub. If the latter is impracticable
then I'd advise putting in four earth rods to form an exscribed square
enclosing the tub site and its immediate surroundings. These should be
connected together and to the local main earth terminal using 16 mm^2
copper conductors. I presume the water supply is via plastic pipe, but
any local copper plumbing that is in contact with the ground should be
main-bonded to the local main earth terminal in 10 or 16 mm^2.

HTH
--
Andy

In message , Guy King
writes
The message
from Grimly Curmudgeon contains these words:

If you can find an electrochemical pair that can make 35 volts with a
single cell you're going to be rich beyond the dreams of avarice!

The Soap and FartGas Cell?

Hmmm, methane fuel-cells. Won't the sulphur contamination poison the
cell like it does the rest of us?

I wonder if there are any figures relating to how human flatulence
contributes to global warming

.... and hence how bad a vegetarian diet might be for the planet

--
geoff

"Andy Wade" wrote in message
...
Sparks wrote:

A friend of mine has just (Yesterday) had a hot tub installed at his
house, in the garden.

In the open, or in some kind of outbuilding? What is the 'flooring'
adjacent to the bath? Form later comments it does sound as it it's in the
open.

All seems to work fine.

However, We (I) just (out of curiosity) put one probe of a multimeter in
the water and the other one into the grass next to the tub.

I got a reading of about 35v AC @ 0.12mA between the two.

Presumably you mean 35 V open-circuit voltage (meter on volts) and 0.12 mA
short-circuit current (meter on mA).



Hi Andy, I was hoping you would reply!
Yes, this is correct, meter on volts, one probe in the water and one stuck
in the wet surrounding ground, then meter on mA with the probles in the same
place.

The latter reading is pretty meaningless with the short meter probes just
stuck into the water and ground. Repeat the test between the metalwork of
the bath

There is the problem, the frame is wooden and the tub is fiberglass - there
arn't any metal bits on it!

(presumably earthed to the exported house earth) and a more substantial
electrode in the ground - a 2 ft. offcut of 15 mm copper water pipe is
handy for this.

His earthing is provided by the armour of the main feed to the house.

And the house earthing system is what? TN-S, TN-C-S (PME) or TT?

This is what I meant by "His earthing is provided by the armour of the main
feed to the house" - So I guess TN-S or TN-C-S - how do we tell, or don't we
care?)
There are actually two, single phase, economy 7 meters, side by side in the
house (Snot sure if they are on the same phase). A consumer unit directly
connected to meter 1, then a switch fuse from the other meter, then on to
anoter CU about 8M away in a different room.
The supply to the shed is via the first CU (this has a 30mA RCD and about 8
MCB's) - The earth for this CU is connected to the armour of both incoming
supplies (There are actually two seperate cables, side by side)

35 V is quite a high difference between a supplier's mains earth and the
local ground these days, with their multiply-earthed networks - but it
clearly can occur. What's more to the point is that it might only take
one fault in the network to turn that 35 V into 230 V and that would make
getting in and out of the bath rather dangerous...

This was exactly my thought - not actually causing a physical problem right
now, but it could later.

In fact the whole installation sounds quite dangerous. An exported mains
earth (probably TN) into an outdoor situation and no attempt to make an
equipotential zone around the tub.

There is no metal anywhere near the tub though - the tub is just sitting on
a concrete base about 1ft wider than the tub, then there is mud/grass around
this at the moment - the plan is to deck all around the tub.

Here is a simalar tub http://www.bayocean.com/images/Hot-tub.jpg

And the two 30 mA RCDs in cascade, no discrimination between them, sends
out a message about the lack of competence of the installer.

I assume this is because the house does not have a split load CU....yet!

To use an exported TN earth in this situation the very least I would have
suggested is that there must be a bonded metal grid under the tub and
immediate surroundings, and the bonding should meet the requirements for a
main bonding conductor (min. 6mm^2 for TN-S or 10 for PME). Bits of 2.5
T&E (with 1.5 mm^2 earths) just aren't up to the job here.

The practical fix is to convert this to a local TT system. Isolate and
insulate the exported earth at the outdoor end of the cable and provide a
local earth system to which the tub and all its ancillaries should be
earthed, via a local main earth terminal.

They tub has an earth terminal inside it's control box, but there arn't any
metal parts on or near the tub (Asside from the screws holding the side
panels on, but these are screwed into the wooden structure of the tub)

The local earth system should consist of an adequate rod electrode
(probably 8 ft.) and the aforesaid mat or grid under the tub. If the
latter is impracticable then I'd advise putting in four earth rods to form
an exscribed square enclosing the tub site and its immediate surroundings.
These should be connected together and to the local main earth terminal
using 16 mm^2 copper conductors.

The plan is to deck all around the tub wit hwooden decking.
Does this change anything, as it will them be impossible to have one foot on
the actual ground and another part of the body in the tub.

I presume the water supply is via plastic pipe,

No water supply, it is filled with the aid of a hose (Connected to the
kitchen mixer, so it was filled with warm water, so it was ready to go as
soon as it was full!) (It only holds about 1000l)

but any local copper plumbing that is in contact with the ground should be
main-bonded to the local main earth terminal in 10 or 16 mm^2.

HTH
--
Andy

Thanks for your reply Andy, most appreciated :-)

--
Sparks...
(Not an electrician)

In message , writes
On 19 Sep,
raden wrote:

I wonder if there are any figures relating to how human flatulence
contributes to global warming

... and hence how bad a vegetarian diet might be for the planet

Much better than eating cow, with their flatulence.

I know, but that's not what I asked

Cows don't drink Abbott Ale (well, not normally, anyway)

--
geoff

Sparks wrote:

[Quoting order changed to make arguments flow better.]

There is the problem, the frame is wooden and the tub is fiberglass - there
arn't any metal bits on it!
[...]
There is no metal anywhere near the tub though - the tub is just sitting on
a concrete base about 1ft wider than the tub, then there is mud/grass around
this at the moment - the plan is to deck all around the tub.

Here is a simalar tub http://www.bayocean.com/images/Hot-tub.jpg
[...]
They tub has an earth terminal inside it's control box, but there arn't any
metal parts on or near the tub (Asside from the screws holding the side
panels on, but these are screwed into the wooden structure of the tub)

OK, this clarifies things a bit. The tub is a Class 1 (earthed)
appliance but the tonne of water in it is not in contact with any large
earthed metal surface. Nevertheless there are presumably pump(s) and/or
heater(s) which might bring the water into contact with some earthed
metalwork internally. I now think your 35 V reading is a complete red
herring. The water mass is probably loosely capacitively coupled to
live mains voltage somewhere "in the works" and, being poorly earthed,
is picking up a voltage by capacitive coupling (aka electrostatic
induction). This will be pretty inconsequential from a safety point of
view as the impedances involved are very high. Certainly the 120 uA
touch current you measured is nowhere near high enough to give a
dangerous shock, although it could result in perceptible tingles.

And the house earthing system is what? TN-S, TN-C-S (PME) or TT?

This is what I meant by "His earthing is provided by the armour of the main
feed to the house" - So I guess TN-S or TN-C-S - how do we tell, or don't we
care?)

Oh we do care...

There are actually two, single phase, economy 7 meters, side by side in the
house (Snot sure if they are on the same phase). A consumer unit directly
connected to meter 1, then a switch fuse from the other meter, then on to
anoter CU about 8M away in a different room.
The supply to the shed is via the first CU (this has a 30mA RCD and about 8
MCB's) - The earth for this CU is connected to the armour of both incoming
supplies (There are actually two seperate cables, side by side)

.... if the earthing is to the lead sheath (rather than armour, usually)
of a supply cable then it's almost certainly TN-S.

In fact the whole installation sounds quite dangerous. An exported mains
earth (probably TN) into an outdoor situation and no attempt to make an
equipotential zone around the tub.

That point still stands, although the danger level is perhaps not quite
so high as I first assumed, as there are no exposed-conductive-parts
(i.e. no accessible metalwork connected to the appliance's earth terminal).

And the two 30 mA RCDs in cascade, no discrimination between them, sends
out a message about the lack of competence of the installer.

I assume this is because the house does not have a split load CU....yet!

It's not split-load, but you said it did have an RCD - so there are two
30 mA RCDs in cascade to the tub. An earth fault at the tub could trip
either or both RCDs and, by the sound of it, possibly black out half the
house. This is a violation of Regulations 314-01-01 and 314-01-02 of BS
7671. If there is an intention to convert the relevant house CU to
split-load, with the tub feed on the non-RCD side then there is some
logic to what's been done.

[big snip]

The plan is to deck all around the tub wit hwooden decking.
Does this change anything, as it will them be impossible to have one foot on
the actual ground and another part of the body in the tub.

In principle no, I still think it needs to be converted to a local TT
system by isolating the exported earth. Outdoors things like the
concrete base and wooden decking could well be conductive enough to
allow dangerous shock current to flow. But maybe you don't need to be
quite so anal about the earth system as I suggested at first, if there
really are no exposed-conductive-parts. A good single earth rod
somewhere near the tub is probably adequate.

--
Andy

"Andy Wade" wrote in message
...
Sparks wrote:


I assume this is because the house does not have a split load CU....yet!

It's not split-load, but you said it did have an RCD - so there are two 30
mA RCDs in cascade to the tub. An earth fault at the tub could trip
either or both RCDs and, by the sound of it, possibly black out half the
house. This is a violation of Regulations 314-01-01 and 314-01-02 of BS
7671. If there is an intention to convert the relevant house CU to
split-load, with the tub feed on the non-RCD side then there is some logic
to what's been done.

[big snip]

The plan is to deck all around the tub wit hwooden decking.
Does this change anything, as it will them be impossible to have one foot
on the actual ground and another part of the body in the tub.

In principle no, I still think it needs to be converted to a local TT
system by isolating the exported earth. Outdoors things like the concrete
base and wooden decking could well be conductive enough to allow dangerous
shock current to flow. But maybe you don't need to be quite so anal about
the earth system as I suggested at first, if there really are no
exposed-conductive-parts. A good single earth rod somewhere near the tub
is probably adequate.


This may sound a silly question but; if the pump is double insulated, the
tub and pipework are plastic, what's the earth rod going to be attached to?

Fred wrote:

This may sound a silly question but; if the pump is double insulated, the
tub and pipework are plastic, what's the earth rod going to be attached to?

To the earth terminal which the OP referred to when he said:

They tub has an earth terminal inside it's control box,

So it does appear to be Class 1 equipment with parts that need earthing.
It would be interesting toe have sight of the installation
instructions; are they on the Web anywhere?

--
Andy

On Tue, 19 Sep 2006 19:21:28 GMT Raden wrote :
I wonder if there are any figures relating to how human flatulence
contributes to global warming

.... and hence how bad a vegetarian diet might be for the planet

It doesn't affect it since what is being released is what was taken
in from the atmosphere a short while ago - unlike unlocking the CO2
in buried gas, coal and oil.

In the new Building Regs Part L you get the same effect: put in a
coal stove and the CO2 goes up (as compared with the default electric
secondary heating); put in a woodburner and it tumbles.

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

Tony Bryer wrote:
On Tue, 19 Sep 2006 19:21:28 GMT Raden wrote :
I wonder if there are any figures relating to how human flatulence
contributes to global warming

.... and hence how bad a vegetarian diet might be for the planet

It doesn't affect it since what is being released is what was taken
in from the atmosphere a short while ago - unlike unlocking the CO2
in buried gas, coal and oil.

I am not entirely convinced raden was being serious :-).

.... but allow me to correct this misunderstanding. The problem with
flatulence (both human and bovine) is that it largely consists of
methane (not CO2). Methane is a more powerful greenhouse gas than
carbon dioxide (molecule for molecule), so turning lots of atmospheric
carbon from CO2 to methane would be bad news.

The message
from Tony Bryer contains these words:

I wonder if there are any figures relating to how human flatulence
contributes to global warming

.... and hence how bad a vegetarian diet might be for the planet

It doesn't affect it since what is being released is what was taken
in from the atmosphere a short while ago - unlike unlocking the CO2
in buried gas, coal and oil.

Ah, well, it's not quite that simple. Methane is a much more potent
greenhouse gas than CO2, so converting atmospheric CO2 to CH4 may be
carbon neutral, but it certainly isn't greenhouse neutral.

--
Skipweasel
Pay no attention to that man behind the curtain.

"Andy Wade" wrote in message
...
Fred wrote:

This may sound a silly question but; if the pump is double insulated, the
tub and pipework are plastic, what's the earth rod going to be attached
to?

To the earth terminal which the OP referred to when he said:

They tub has an earth terminal inside it's control box,

So it does appear to be Class 1 equipment with parts that need earthing.
It would be interesting toe have sight of the installation instructions;
are they on the Web anywhere?

--
Andy

I will ask him if his manual has them in!

Thanks for your replies Andy, very helpful :-)

And yes, there is a heater in this tub, it has a metal outer body (Not sure
about the insides!), also, when it was installed, there was a problem with
the blower (that blows bubbles in the tub, I noticed this has an earth
connection too, although, this does not (Should not!) come into contact with
the water, maybe the earth s here too, in case this fan gets flooded somhow.

In message , Tony Bryer
writes
On Tue, 19 Sep 2006 19:21:28 GMT Raden wrote :
I wonder if there are any figures relating to how human flatulence
contributes to global warming

.... and hence how bad a vegetarian diet might be for the planet

It doesn't affect it since what is being released is what was taken
in from the atmosphere a short while ago - unlike unlocking the CO2
in buried gas, coal and oil.

I was thinking more of methane

If I was talking about CO2, I would have used the word "lager"

--
geoff

In message .com,
Martin Bonner writes

Tony Bryer wrote:
On Tue, 19 Sep 2006 19:21:28 GMT Raden wrote :
I wonder if there are any figures relating to how human flatulence
contributes to global warming

.... and hence how bad a vegetarian diet might be for the planet

It doesn't affect it since what is being released is what was taken
in from the atmosphere a short while ago - unlike unlocking the CO2
in buried gas, coal and oil.

I am not entirely convinced raden was being serious :-).

... but allow me to correct this misunderstanding. The problem with
flatulence (both human and bovine) is that it largely consists of
methane (not CO2). Methane is a more powerful greenhouse gas than
carbon dioxide (molecule for molecule), so turning lots of atmospheric
carbon from CO2 to methane would be bad news.

Gold star that man

--
geoff