In article ,
harryagain wrote:

"tony sayer" wrote in message
...
In article , harryagain
scribeth thus

"tony sayer" wrote in message
...
A Perfick sine wave is the one thing you will not see;!...

And how exactly will you see how perfect or not perfect it is? Just
eyeball
it?
Heh heh, You are as bad as TurNiP

The only way to be absolutely sure is to get a piece of graph paper
and
some
sine tables and draw your own.
And those tables were derived geometrically not by some stupid
computer.
Similar geometry to that going on in an alternator.
And any non sinusiodal AC passed through inductors and capacitors,
gradually
gets to look more and more like a sine wave interestingly.




.

There are lot of distortions on the mains waveform.


Answer this question if you will. Have you got an Oscilloscope or
not?..

No.


Well perhaps you should then you'll se what the mains really does look
like;!..


I saw it years ago. It was only a mildly interesting experience that I
wouldn't be interested in repeating.

I don't recall any significant "distortion". Just an occasional spike.

Why do you suppose the mains would have a non sine wave? Every effort is
made t omake it a sine wave.
Sine waves comenaturally toany rotating electrical device
Any deviation reduces the efficiency of any AC magnetic device



Harry .. things have moved in since you looked after your boilers.

The mains these days has some rather "unpleasant" loading on it usually
by semiconductor devices not transformers near saturation. Why is it
that I can clearly see these even late at night when the loading on
substation transformers goes right down?.

Answer me that one if you will..

The electrical load controlled by electronic devices is trivial compared
with total load.


True, but a few "not very good" fluorescent lights can make mains cables
radiate on medium wave for quite a long way.

--
From KT24

Using a RISC OS computer running v5.18

On 30/09/13 22:03, Huge wrote:
On 2013-09-30, Andy Burns wrote:
harryagain wrote:

The electrical load controlled by electronic devices is trivial compared
with total load.

How much power do you think datacentres gobble up?

Tens of megawatts.


I think that's a little on the high side, megawatts, yes.


--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

The Natural Philosopher wrote:

Huge wrote:

Andy Burns wrote:

How much power do you think datacentres gobble up?

Tens of megawatts.

I think that's a little on the high side, megawatts, yes.

3-4MW is about right for each of the datacentres we have servers in,
what fraction of those MW are sipped during the peaks of the sine wave?
How many "big" UK datacentres? 40-50 maybe?

On 30/09/13 22:49, Andy Burns wrote:
The Natural Philosopher wrote:

Huge wrote:

Andy Burns wrote:

How much power do you think datacentres gobble up?

Tens of megawatts.

I think that's a little on the high side, megawatts, yes.

3-4MW is about right for each of the datacentres we have servers in,
what fraction of those MW are sipped during the peaks of the sine wave?
How many "big" UK datacentres? 40-50 maybe?


Just about ANY electronics tends to have an SMPS strapped on it. And
they are ALL peak clippers.

It's a huge change from the days when the load on the grid was largely
resistive (lighting) and slightly inductive (electric motors).

Peak currents are much higher than the average..the current waveform is
far from sinusoidal. This leads to far higher losses in the resistive
parts of the grid.

--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

harryagain wrote:
Why do you suppose that "iron losses" in AC motors and tranformers are
almost constant regardless of load.
Not for the reasons you suppose.

The iron losses are constant because the flux is constant.

The flux varies with the current. That's how a transformer works. The
current in the primary winding varies, which causes the magnetic flux in
the core to vary, which generates current in the secondary winding.

The losses in iron cores are due to hysteresis, which is a non-linearity
in magnetic response of the iron to changing magnetic fields,
particularly ones that reverse periodically. Entropy and quantum effects
are involved.

--
Tciao for Now!

John.

The Natural Philosopher wrote:
On 30/09/13 22:03, Huge wrote:
On 2013-09-30, Andy Burns wrote:
harryagain wrote:

The electrical load controlled by electronic devices is trivial
compared
with total load.

How much power do you think datacentres gobble up?

Tens of megawatts.


I think that's a little on the high side, megawatts, yes.


Each.....

--
Tciao for Now!

John.

John Williamson wrote:

The Natural Philosopher wrote:

I think that's a little on the high side, megawatts, yes.

Each.....

In 2011 the total UK datacentre power was estimated[1] as 6.4GW with
6.7% growth P/A. Assume half that's cooling, so relatively smooth
inductive load, and the other 3.2GW is consumed during 4ms out of every
20ms cycle, which makes it equivalent to 16GW peak, or 2/3 of the UK's
average base load ... still insignificant Harry?


[1]
http://www.techweekeurope.co.uk/news/uk-data-centre-power-could-fuel-6m-homes-46116

On 30/09/13 23:46, John Williamson wrote:
harryagain wrote:
Why do you suppose that "iron losses" in AC motors and tranformers are
almost constant regardless of load.
Not for the reasons you suppose.

The iron losses are constant because the flux is constant.

The flux varies with the current. That's how a transformer works. The
current in the primary winding varies, which causes the magnetic flux in
the core to vary, which generates current in the secondary winding.

The losses in iron cores are due to hysteresis, which is a non-linearity
in magnetic response of the iron to changing magnetic fields,
particularly ones that reverse periodically. Entropy and quantum effects
are involved.

No point in trying to educate harry.
He thinks he knows it all already.

--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

On 01/10/13 08:22, Huge wrote:
The Natural Philosopher wrote:

Huge wrote:

Andy Burns wrote:

How much power do you think datacentres gobble up?

Tens of megawatts.

I think that's a little on the high side, megawatts, yes.

Yes, but you're a tosser and I actually know what our data centre draws.



your data centre draws over ten megawatts?


--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

"John Williamson" wrote in message
...
harryagain wrote:
Why do you suppose that "iron losses" in AC motors and tranformers are
almost constant regardless of load.
Not for the reasons you suppose.

The iron losses are constant because the flux is constant.

The flux varies with the current. That's how a transformer works. The
current in the primary winding varies, which causes the magnetic flux in
the core to vary, which generates current in the secondary winding.

The losses in iron cores are due to hysteresis, which is a non-linearity
in magnetic response of the iron to changing magnetic fields, particularly
ones that reverse periodically. Entropy and quantum effects are involved.

Exactly wrong.
Another one weak on electrical theory.
That is an incorrect schoolboy supposition.
For a more exact schoolboy explanation, the flux in the secondary winding
exactly equals and opposes that in the primary. Hence they remain constant
regardles of load.

Also you need to look up what hysteresis is . It is not what you are
implying above.
It's just an adjective that could be applied to a rubber block, or a spring.
It's not a particular electrical term.

http://uk.answers.yahoo.com/question...5225019AA7vJEf

I know how iron losses occur, they are constant regardless of load.
"Copper losses" (resistive) vary with load. I x I x R.

"The Natural Philosopher" wrote in message
...
On 30/09/13 23:46, John Williamson wrote:
harryagain wrote:
Why do you suppose that "iron losses" in AC motors and tranformers are
almost constant regardless of load.
Not for the reasons you suppose.

The iron losses are constant because the flux is constant.

The flux varies with the current. That's how a transformer works. The
current in the primary winding varies, which causes the magnetic flux in
the core to vary, which generates current in the secondary winding.

The losses in iron cores are due to hysteresis, which is a non-linearity
in magnetic response of the iron to changing magnetic fields,
particularly ones that reverse periodically. Entropy and quantum effects
are involved.

No point in trying to educate harry.
He thinks he knows it all already.


While you are as thick as they come.
Shouting your big mouth off from a position of zero knowledge of even
elementary schoolboy physics.

"Andy Burns" wrote in message
o.uk...
harryagain wrote:

The electrical load controlled by electronic devices is trivial compared
with total load.

How much power do you think datacentres gobble up? Vast warehouses full
of rack upon rack of servers with SMPSUs ...

Trivial.
And most of it is in ventiilation anyway, nothing to do with electronics.

"The Natural Philosopher" wrote in message
...
On 30/09/13 22:49, Andy Burns wrote:
The Natural Philosopher wrote:

Huge wrote:

Andy Burns wrote:

How much power do you think datacentres gobble up?

Tens of megawatts.

I think that's a little on the high side, megawatts, yes.

3-4MW is about right for each of the datacentres we have servers in,
what fraction of those MW are sipped during the peaks of the sine wave?
How many "big" UK datacentres? 40-50 maybe?


Just about ANY electronics tends to have an SMPS strapped on it. And they
are ALL peak clippers.

It's a huge change from the days when the load on the grid was largely
resistive (lighting) and slightly inductive (electric motors).

Peak currents are much higher than the average..the current waveform is
far from sinusoidal. This leads to far higher losses in the resistive
parts of the grid.


Twaddle.

On 01/10/13 09:31, harryagain wrote:
"John Williamson" wrote in message
...
harryagain wrote:
Why do you suppose that "iron losses" in AC motors and tranformers are
almost constant regardless of load.
Not for the reasons you suppose.

The iron losses are constant because the flux is constant.

The flux varies with the current. That's how a transformer works. The
current in the primary winding varies, which causes the magnetic flux in
the core to vary, which generates current in the secondary winding.

The losses in iron cores are due to hysteresis, which is a non-linearity
in magnetic response of the iron to changing magnetic fields, particularly
ones that reverse periodically. Entropy and quantum effects are involved.

Exactly wrong.
Another one weak on electrical theory.
That is an incorrect schoolboy supposition.
For a more exact schoolboy explanation, the flux in the secondary winding
exactly equals and opposes that in the primary. Hence they remain constant
regardles of load.

Also you need to look up what hysteresis is . It is not what you are
implying above.
It's just an adjective that could be applied to a rubber block, or a spring.
It's not a particular electrical term.

http://uk.answers.yahoo.com/question...5225019AA7vJEf

I know how iron losses occur, they are constant regardless of load.
"Copper losses" (resistive) vary with load. I x I x R.


Oh dear. Iron losses are DEFINED to be 'that part of the losses athat
can be regared as approximately constant with load'

Andf if te fluxes exactly cancel each other out, why botheer to put the
iron there in the frst place and make transformers so big? patently the
net fluxes do not actually exist as a net component! so even a small
transformer will transfer gigawatts!


The trouble with simple models is that they only model a small part of
the truth, and they are not the whole truth, and nothing but the truth.

Oner begigns to understand why you believe in AGW and renewable energy...

--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

On 01/10/13 09:33, harryagain wrote:
"The Natural Philosopher" wrote in message
...
On 30/09/13 23:46, John Williamson wrote:
harryagain wrote:
Why do you suppose that "iron losses" in AC motors and tranformers are
almost constant regardless of load.
Not for the reasons you suppose.

The iron losses are constant because the flux is constant.

The flux varies with the current. That's how a transformer works. The
current in the primary winding varies, which causes the magnetic flux in
the core to vary, which generates current in the secondary winding.

The losses in iron cores are due to hysteresis, which is a non-linearity
in magnetic response of the iron to changing magnetic fields,
particularly ones that reverse periodically. Entropy and quantum effects
are involved.

No point in trying to educate harry.
He thinks he knows it all already.


While you are as thick as they come.
Shouting your big mouth off from a position of zero knowledge of even
elementary schoolboy physics.


The prob;lem is harry, that I am a qualifiued trained and practicing
negineere who has actually DESIGNED transformers, so I know MORE than
the elementary schoolboy physics.



--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

"Andy Burns" wrote in message
...
John Williamson wrote:

The Natural Philosopher wrote:

I think that's a little on the high side, megawatts, yes.

Each.....

In 2011 the total UK datacentre power was estimated[1] as 6.4GW with 6.7%
growth P/A. Assume half that's cooling, so relatively smooth inductive
load, and the other 3.2GW is consumed during 4ms out of every 20ms cycle,
which makes it equivalent to 16GW peak, or 2/3 of the UK's average base
load ... still insignificant Harry?


[1]
http://www.techweekeurope.co.uk/news/uk-data-centre-power-could-fuel-6m-homes-46116

Most of it goes on cooling/ventilation not DC driven cevices.
I was reading only lately that data centres are being moved to colder
climates than ours to get round the energy consumption /cost problem.
Finland & Canada being favourite.
http://www.theglobeandmail.com/repor...rticle6598555/

On 01/10/13 09:37, harryagain wrote:
"The Natural Philosopher" wrote in message
...
On 30/09/13 22:49, Andy Burns wrote:
The Natural Philosopher wrote:

Huge wrote:

Andy Burns wrote:

How much power do you think datacentres gobble up?

Tens of megawatts.

I think that's a little on the high side, megawatts, yes.

3-4MW is about right for each of the datacentres we have servers in,
what fraction of those MW are sipped during the peaks of the sine wave?
How many "big" UK datacentres? 40-50 maybe?


Just about ANY electronics tends to have an SMPS strapped on it. And they
are ALL peak clippers.

It's a huge change from the days when the load on the grid was largely
resistive (lighting) and slightly inductive (electric motors).

Peak currents are much higher than the average..the current waveform is
far from sinusoidal. This leads to far higher losses in the resistive
parts of the grid.


Twaddle.


strap a current probe on the mains and plug the probe into an
oscilloscope and the mains into any item of electronics.

just DO it harry.

Or just THINK for a moment how a sine wave and a rectifier can charge up
a capacitor ins a standard single phase pridge rectifier and capacitor
arrangement, such as every power supply that produces DC off the mains
uses, when for the greater part of the cycle the diodes are reverse
biased and cannot conduct any (significant) current at all.


--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

On 01/10/13 09:47, harryagain wrote:
"Andy Burns" wrote in message
...
John Williamson wrote:

The Natural Philosopher wrote:

I think that's a little on the high side, megawatts, yes.

Each.....

In 2011 the total UK datacentre power was estimated[1] as 6.4GW with 6.7%
growth P/A. Assume half that's cooling, so relatively smooth inductive
load, and the other 3.2GW is consumed during 4ms out of every 20ms cycle,
which makes it equivalent to 16GW peak, or 2/3 of the UK's average base
load ... still insignificant Harry?


[1]
http://www.techweekeurope.co.uk/news/uk-data-centre-power-could-fuel-6m-homes-46116


" Power consumption in UK data centres was estimated to be 6.4GW annually."

Interesting. What is anuual power consumption? Energy? GW isnt energy...

Most of it goes on cooling/ventilation not DC driven cevices.

twaddle.

even basic schoolboy theory will tell you that a heat pump can remove
3-4 times the power it consumes in terms of heat, so the natural ratio
would be 75% -80% devices producing (unwanted) heat and 20-25% running
the aircon.

I was reading only lately that data centres are being moved to colder
climates than ours to get round the energy consumption /cost problem.
Finland & Canada being favourite.
http://www.theglobeandmail.com/repor...rticle6598555/


The far more relevant transition going on is the massive move to virtual
servers where one server can replace up to 50 (or more) servers running
different applications on different operating systems with a single
piece of hardware, and the recognition that 'megaflops per watt' is a
figure CPU designers should be optimising.



--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

On Sun, 29 Sep 2013 18:45:53 +0100, "harryagain"
wrote:

If voltage is constant, the flux in the core is constant from zero load to
full load.

It is possible to remove all the flux, even from a transformer vbg

http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=860402&MER=bn-me-pd-r3-cust-all-860402


--

In article , harryagain
scribeth thus

"tony sayer" wrote in message
...
In article , harryagain
scribeth thus

"tony sayer" wrote in message
...
A Perfick sine wave is the one thing you will not see;!...

And how exactly will you see how perfect or not perfect it is? Just
eyeball
it?
Heh heh, You are as bad as TurNiP

The only way to be absolutely sure is to get a piece of graph paper
and
some
sine tables and draw your own.
And those tables were derived geometrically not by some stupid
computer.
Similar geometry to that going on in an alternator.
And any non sinusiodal AC passed through inductors and capacitors,
gradually
gets to look more and more like a sine wave interestingly.




.

There are lot of distortions on the mains waveform.


Answer this question if you will. Have you got an Oscilloscope or
not?..

No.


Well perhaps you should then you'll se what the mains really does look
like;!..


I saw it years ago. It was only a mildly interesting experience that I
wouldn't be interested in repeating.

I don't recall any significant "distortion". Just an occasional spike.

Why do you suppose the mains would have a non sine wave? Every effort is
made t omake it a sine wave.
Sine waves comenaturally toany rotating electrical device
Any deviation reduces the efficiency of any AC magnetic device



Harry .. things have moved in since you looked after your boilers.

The mains these days has some rather "unpleasant" loading on it usually
by semiconductor devices not transformers near saturation. Why is it
that I can clearly see these even late at night when the loading on
substation transformers goes right down?.

Answer me that one if you will..

The electrical load controlled by electronic devices is trivial compared
with total load.



Then why do they cause waveform distortion and why does the mains get
distorted?..

Even with very light transformer loading's?..
--
Tony Sayer

In article , The Natural Philosopher
scribeth thus
On 30/09/13 22:49, Andy Burns wrote:
The Natural Philosopher wrote:

Huge wrote:

Andy Burns wrote:

How much power do you think datacentres gobble up?

Tens of megawatts.

I think that's a little on the high side, megawatts, yes.

3-4MW is about right for each of the datacentres we have servers in,
what fraction of those MW are sipped during the peaks of the sine wave?
How many "big" UK datacentres? 40-50 maybe?


Just about ANY electronics tends to have an SMPS strapped on it. And
they are ALL peak clippers.

It's a huge change from the days when the load on the grid was largely
resistive (lighting) and slightly inductive (electric motors).



Peak currents are much higher than the average..the current waveform is
far from sinusoidal. This leads to far higher losses in the resistive
parts of the grid.


In days of yore I had to manage a TV repair shope and in those days we
used to have a lot of the Philips G8 chassis sets which used a single
thyristor in the power unit.

However from time to time we used to have a rather odd complaint that
when the telly was switched on the lights would flicker and when TV was
switched off all was well.

Invariably it was caused buy a duff high resistance joint in the fuse
box or incoming mains supply.

That HR joint could cope with resistive loads OK, but the odd half wave
demand of the TV caused it to play up and cause the effects alluded to
above. We had known duff meter connections that would supply the cooker
etc but when the TV was switched on then the flickering started!....

--
Tony Sayer

True, but a few "not very good" fluorescent lights can make mains cables
radiate on medium wave for quite a long way.


I have known that up to the 440 MHz band!...
--
Tony Sayer

On 01/10/2013 10:00, The Natural Philosopher wrote:
On 01/10/13 09:47, harryagain wrote:
"Andy Burns" wrote in message
...
John Williamson wrote:

The Natural Philosopher wrote:

I think that's a little on the high side, megawatts, yes.

Each.....

In 2011 the total UK datacentre power was estimated[1] as 6.4GW
with 6.7% growth P/A. Assume half that's cooling, so relatively
smooth inductive load, and the other 3.2GW is consumed during 4ms
out of every 20ms cycle, which makes it equivalent to 16GW peak,
or 2/3 of the UK's average base load ... still insignificant
Harry?


[1]
http://www.techweekeurope.co.uk/news/uk-data-centre-power-could-fuel-6m-homes-46116




" Power consumption in UK data centres was estimated to be 6.4GW
annually."

Interesting. What is anuual power consumption? Energy? GW isnt
energy...

Most of it goes on cooling/ventilation not DC driven cevices.

twaddle.

even basic schoolboy theory will tell you that a heat pump can remove
3-4 times the power it consumes in terms of heat, so the natural
ratio would be 75% -80% devices producing (unwanted) heat and 20-25%
running the aircon.

I was reading only lately that data centres are being moved to
colder climates than ours to get round the energy consumption /cost
problem. Finland & Canada being favourite.
http://www.theglobeandmail.com/repor...rticle6598555/




The far more relevant transition going on is the massive move to
virtual servers where one server can replace up to 50 (or more)
servers running different applications on different operating systems
with a single piece of hardware, and the recognition that 'megaflops
per watt' is a figure CPU designers should be optimising.




There is a move towards putting data centres where its cold so you can
avoid the cost of cooling. Some are being sited in Iceland where they
can be hit by volcanoes!


I wonder if it will be like Japan, have standby generators 25 miles away
from a nuke melting down and deciding not to use them?

On 01/10/2013 09:47, harryagain wrote:
"Andy Burns" wrote in message
...
John Williamson wrote:

The Natural Philosopher wrote:

I think that's a little on the high side, megawatts, yes.

Each.....

In 2011 the total UK datacentre power was estimated[1] as 6.4GW with 6.7%
growth P/A. Assume half that's cooling, so relatively smooth inductive
load, and the other 3.2GW is consumed during 4ms out of every 20ms cycle,
which makes it equivalent to 16GW peak, or 2/3 of the UK's average base
load ... still insignificant Harry?


[1]
http://www.techweekeurope.co.uk/news/uk-data-centre-power-could-fuel-6m-homes-46116

Most of it goes on cooling/ventilation not DC driven cevices.

That does not really stand up to even a cursory analysis though does it?

Think about how efficient a modern air conditioning system is...
(consider the meaning of COP in these circumstance)

Now think about the energy that you are needing to pump away, to
maintain an equilibrium temperature in your data centre. Where does it
come from?

Hopefully, it should now be obvious that a cooling power load can't
represent "most" of the energy consumption.

--
Cheers,

John.

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

On 01/10/13 13:16, tony sayer wrote:


True, but a few "not very good" fluorescent lights can make mains cables
radiate on medium wave for quite a long way.


I have known that up to the 440 MHz band!...

the speed of striking of a fluorescent is..pretty high!


--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

On 01/10/2013 09:37, harryagain wrote:
"The Natural Philosopher" wrote in message
...
On 30/09/13 22:49, Andy Burns wrote:
The Natural Philosopher wrote:

Huge wrote:

Andy Burns wrote:

How much power do you think datacentres gobble up?

Tens of megawatts.

I think that's a little on the high side, megawatts, yes.

3-4MW is about right for each of the datacentres we have servers in,
what fraction of those MW are sipped during the peaks of the sine wave?
How many "big" UK datacentres? 40-50 maybe?


Just about ANY electronics tends to have an SMPS strapped on it. And they
are ALL peak clippers.

It's a huge change from the days when the load on the grid was largely
resistive (lighting) and slightly inductive (electric motors).

Peak currents are much higher than the average..the current waveform is
far from sinusoidal. This leads to far higher losses in the resistive
parts of the grid.


Twaddle.

Yes, but only if by "twaddle" you mean, "yes that is a pretty good
description", then you are right.

Here I drew it for you:

http://wiki.diyfaq.org.uk/images/e/e...simulation.png

The waveform shows voltage at R2 and current through it.


--
Cheers,

John.

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

harryagain wrote:

"Andy Burns" wrote:

In 2011 the total UK datacentre power was estimated[1] as 6.4GW with 6.7%
growth P/A. Assume half that's cooling

Most of it goes on cooling/ventilation not DC driven cevices.

Actually I think taking a figure of half for cooling is quite fair, one
of the datacentres we use has active and passive cooling, and they only
use the active cooling at times of year that demand it, that one in
probably 25-30% cooling.

I was reading only lately that data centres are being moved to colder
climates than ours to get round the energy consumption /cost problem.

There certainly is an element of that going on.

On 01/10/2013 09:36, harryagain wrote:
"Andy Burns" wrote in message
o.uk...
harryagain wrote:

The electrical load controlled by electronic devices is trivial compared
with total load.

How much power do you think datacentres gobble up? Vast warehouses full
of rack upon rack of servers with SMPSUs ...

Trivial.
And most of it is in ventiilation anyway, nothing to do with electronics.

Where is the heat that needs ventilating coming from harry?


--
Cheers,

John.

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

"The Natural Philosopher" wrote in message
...
On 01/10/13 09:33, harryagain wrote:
"The Natural Philosopher" wrote in message
...
On 30/09/13 23:46, John Williamson wrote:
harryagain wrote:
Why do you suppose that "iron losses" in AC motors and tranformers
are
almost constant regardless of load.
Not for the reasons you suppose.

The iron losses are constant because the flux is constant.

The flux varies with the current. That's how a transformer works. The
current in the primary winding varies, which causes the magnetic flux
in
the core to vary, which generates current in the secondary winding.

The losses in iron cores are due to hysteresis, which is a
non-linearity
in magnetic response of the iron to changing magnetic fields,
particularly ones that reverse periodically. Entropy and quantum
effects
are involved.

No point in trying to educate harry.
He thinks he knows it all already.


While you are as thick as they come.
Shouting your big mouth off from a position of zero knowledge of even
elementary schoolboy physics.


The prob;lem is harry, that I am a qualifiued trained and practicing
negineere who has actually DESIGNED transformers, so I know MORE than the
elementary schoolboy physics.


What ********.
You don't even know how they work.

"John Rumm" wrote in message
o.uk...
On 01/10/2013 09:37, harryagain wrote:
"The Natural Philosopher" wrote in message
...
On 30/09/13 22:49, Andy Burns wrote:
The Natural Philosopher wrote:

Huge wrote:

Andy Burns wrote:

How much power do you think datacentres gobble up?

Tens of megawatts.

I think that's a little on the high side, megawatts, yes.

3-4MW is about right for each of the datacentres we have servers in,
what fraction of those MW are sipped during the peaks of the sine wave?
How many "big" UK datacentres? 40-50 maybe?


Just about ANY electronics tends to have an SMPS strapped on it. And
they
are ALL peak clippers.

It's a huge change from the days when the load on the grid was largely
resistive (lighting) and slightly inductive (electric motors).

Peak currents are much higher than the average..the current waveform is
far from sinusoidal. This leads to far higher losses in the resistive
parts of the grid.


Twaddle.

Yes, but only if by "twaddle" you mean, "yes that is a pretty good
description", then you are right.

Here I drew it for you:

http://wiki.diyfaq.org.uk/images/e/e...simulation.png

The waveform shows voltage at R2 and current through it.

There is a bridge (full wave) rectifier feeding a resistor & capacitor in
parallel hence I is leading V.
Not a circuit that serves any useful purpose.
It might represent a bit of wire.
And not a "Peak clipper"
And the power consumed is trivial.
What bearing has this on the OP?

"The Natural Philosopher" wrote in message
...
On 01/10/13 09:47, harryagain wrote:
"Andy Burns" wrote in message
...
John Williamson wrote:

The Natural Philosopher wrote:

I think that's a little on the high side, megawatts, yes.

Each.....

In 2011 the total UK datacentre power was estimated[1] as 6.4GW with
6.7%
growth P/A. Assume half that's cooling, so relatively smooth inductive
load, and the other 3.2GW is consumed during 4ms out of every 20ms
cycle,
which makes it equivalent to 16GW peak, or 2/3 of the UK's average base
load ... still insignificant Harry?


[1]
http://www.techweekeurope.co.uk/news/uk-data-centre-power-could-fuel-6m-homes-46116


" Power consumption in UK data centres was estimated to be 6.4GW
annually."

Interesting. What is anuual power consumption? Energy? GW isnt energy...

Most of it goes on cooling/ventilation not DC driven cevices.

twaddle.

even basic schoolboy theory will tell you that a heat pump can remove 3-4
times the power it consumes in terms of heat, so the natural ratio would
be 75% -80% devices producing (unwanted) heat and 20-25% running the
aircon.

Most of it goes on the fans shifting air.

"John Rumm" wrote in message
o.uk...
On 01/10/2013 09:47, harryagain wrote:
"Andy Burns" wrote in message
...
John Williamson wrote:

The Natural Philosopher wrote:

I think that's a little on the high side, megawatts, yes.

Each.....

In 2011 the total UK datacentre power was estimated[1] as 6.4GW with
6.7%
growth P/A. Assume half that's cooling, so relatively smooth inductive
load, and the other 3.2GW is consumed during 4ms out of every 20ms
cycle,
which makes it equivalent to 16GW peak, or 2/3 of the UK's average base
load ... still insignificant Harry?


[1]
http://www.techweekeurope.co.uk/news/uk-data-centre-power-could-fuel-6m-homes-46116

Most of it goes on cooling/ventilation not DC driven cevices.

That does not really stand up to even a cursory analysis though does it?

Think about how efficient a modern air conditioning system is... (consider
the meaning of COP in these circumstance)

Now think about the energy that you are needing to pump away, to maintain
an equilibrium temperature in your data centre. Where does it come from?

Hopefully, it should now be obvious that a cooling power load can't
represent "most" of the energy consumption.

Most of it goes on fans and pumps shifting air and water.

harryagain wrote:

Most of it goes on fans and pumps shifting air and water.

The fans that are drawing air from the cold aisle and exhausting it to
the hot aisle are *internal* to the servers, therefore powered by the DC
PSU in the servers.

"John Rumm" wrote in message
o.uk...
On 01/10/2013 09:36, harryagain wrote:
"Andy Burns" wrote in message
o.uk...
harryagain wrote:

The electrical load controlled by electronic devices is trivial
compared
with total load.

How much power do you think datacentres gobble up? Vast warehouses full
of rack upon rack of servers with SMPSUs ...

Trivial.
And most of it is in ventiilation anyway, nothing to do with electronics.

Where is the heat that needs ventilating coming from harry?


It comes from the heatsinks on electronic components and from people in
these data centres.
Also from the lighting, the screens (CRT or flat).
From cooking and coffee making.

But mostly from solar gain.
Hence the idea of buggering off elsewhere where it is cold/solar gain is
less.

"Huge" wrote in message
...

On 01/10/2013 09:36, harryagain wrote:
"Andy Burns" wrote in message
o.uk...
harryagain wrote:

The electrical load controlled by electronic devices is trivial
compared
with total load.

How much power do you think datacentres gobble up? Vast warehouses
full
of rack upon rack of servers with SMPSUs ...

Trivial.

Jesus, harry, but you're an ignorant ****.

About half of electricity generated goes to domestic use.
The remainder is split amongst various industrial/commercial users.

"tony sayer" wrote in message
...
In article , harryagain
scribeth thus

"tony sayer" wrote in message
...
In article , harryagain
scribeth thus

"tony sayer" wrote in message
...
A Perfick sine wave is the one thing you will not see;!...

And how exactly will you see how perfect or not perfect it is? Just
eyeball
it?
Heh heh, You are as bad as TurNiP

The only way to be absolutely sure is to get a piece of graph paper
and
some
sine tables and draw your own.
And those tables were derived geometrically not by some stupid
computer.
Similar geometry to that going on in an alternator.
And any non sinusiodal AC passed through inductors and capacitors,
gradually
gets to look more and more like a sine wave interestingly.




.

There are lot of distortions on the mains waveform.


Answer this question if you will. Have you got an Oscilloscope or
not?..

No.


Well perhaps you should then you'll se what the mains really does look
like;!..


I saw it years ago. It was only a mildly interesting experience that I
wouldn't be interested in repeating.

I don't recall any significant "distortion". Just an occasional spike.

Why do you suppose the mains would have a non sine wave? Every effort is
made t omake it a sine wave.
Sine waves comenaturally toany rotating electrical device
Any deviation reduces the efficiency of any AC magnetic device



Harry .. things have moved in since you looked after your boilers.

The mains these days has some rather "unpleasant" loading on it usually
by semiconductor devices not transformers near saturation. Why is it
that I can clearly see these even late at night when the loading on
substation transformers goes right down?.

Answer me that one if you will..

The electrical load controlled by electronic devices is trivial compared
with total load.



Then why do they cause waveform distortion and why does the mains get
distorted?..

Even with very light transformer loading's?..
--
Tony Sayer

it's not them that does it.

harryagain wrote:

"John Rumm" wrote:

Where is the heat that needs ventilating coming from harry?

It comes from the heatsinks on electronic components and from people in
these data centres.

They run like ghost ships

Also from the lighting,

Ever heard of the phrase "lights off computing"?

the screens (CRT or flat).

There's probbly one screen per several hundred servers, sitting on a sad
little trolley with a mouse and keyboard, first dibs to who needs it.

From cooking and coffee making.

boggle

On 01/10/13 19:14, harryagain wrote:
"John Rumm" wrote in message
o.uk...
On 01/10/2013 09:36, harryagain wrote:
"Andy Burns" wrote in message
o.uk...
harryagain wrote:

The electrical load controlled by electronic devices is trivial
compared
with total load.

How much power do you think datacentres gobble up? Vast warehouses full
of rack upon rack of servers with SMPSUs ...

Trivial.
And most of it is in ventiilation anyway, nothing to do with electronics.

Where is the heat that needs ventilating coming from harry?


It comes from the heatsinks on electronic components and from people in
these data centres.
Also from the lighting, the screens (CRT or flat).
From cooking and coffee making.

But mostly from solar gain.

you havent been in a dark office ever, have you harry?

Hence the idea of buggering off elsewhere where it is cold/solar gain is
less.


keep digging..i'll get the popcorn.



--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

On 01/10/2013 10:00, The Natural Philosopher wrote:
even basic schoolboy theory will tell you that a heat pump can remove
3-4 times the power it consumes in terms of heat, so the natural ratio
would be 75% -80% devices producing (unwanted) heat and 20-25% running
the aircon.

Errmmm...

http://www.google.co.uk/about/datace...ency/internal/

"Most data centers use just as much non-computing or €œoverhead€� energy
(like cooling and power conversion) as they do to power their servers."

Andy

On 01/10/2013 19:14, harryagain wrote:
It comes from the heatsinks on electronic components and from people in
these data centres.
Also from the lighting, the screens (CRT or flat).
From cooking and coffee making.

But mostly from solar gain.
Hence the idea of buggering off elsewhere where it is cold/solar gain is
less.

Place my son works in has its own substations, and about 6 people in it.
Maybe a kilowatt for the people. There are very few screens (most are
headless) the lights are off when there's no-one near. And there aren't
any windows, which cuts down the solar gain somewhat...

It all comes out of the electronics. Mostly the fat things with
heatsinks, but not all.

Andy