Can someone confirm that power factor is NOT taken into consideration for domestic supplies? I have a feeling it isn't, but I can't find any information on the internet. If it matters, it's a modern (5 years old) electronic meter I have. The power factor in my house is an average of 0.7 so depending if it's charged for or not, my bill could be completely different.

--
Tip: Don't substitute salt for sugar in recipes.
It tastes like ****.

On 17/04/2014 01:07, Uncle Peter wrote:
Can someone confirm that power factor is NOT taken into consideration
for domestic supplies? I have a feeling it isn't, but I can't find any
information on the internet. If it matters, it's a modern (5 years
old) electronic meter I have. The power factor in my house is an
average of 0.7 so depending if it's charged for or not, my bill could be
completely different.

Domestic meters only record real power...


--
Cheers,

John.

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

"Uncle Peter" wrote in message
news
Can someone confirm that power factor is NOT taken into consideration for
domestic supplies? I have a feeling it isn't, but I can't find any
information on the internet. If it matters, it's a modern (5 years old)
electronic meter I have. The power factor in my house is an average of
0.7 so depending if it's charged for or not, my bill could be completely
different.


The very fact that you pay for kilowatt hours (Kwh) not kilovoltamps hours
(Kvah) tells you that power factor is not accounted for.
Only commercial organisations might be asked to pay for Kvah.

So how does this affect actual loading of the system. Is it large enough for
them to really be losing out?
I can remember that when I worked in a factory, the leccy board came
around and wanted to redistribute the soak test racks and other things to
different mains phases due to imbalance of power factor due to the method
the ssets used to get power.
It always made me wonder how, if this was so bad, why it made no difference
when they wer in peoples homes.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"harryagain" wrote in message
...

"Uncle Peter" wrote in message
news
Can someone confirm that power factor is NOT taken into consideration for
domestic supplies? I have a feeling it isn't, but I can't find any
information on the internet. If it matters, it's a modern (5 years old)
electronic meter I have. The power factor in my house is an average of
0.7 so depending if it's charged for or not, my bill could be completely
different.


The very fact that you pay for kilowatt hours (Kwh) not kilovoltamps
hours (Kvah) tells you that power factor is not accounted for.
Only commercial organisations might be asked to pay for Kvah.

On Thu, 17 Apr 2014 01:37:01 +0100, John Rumm wrote:

On 17/04/2014 01:07, Uncle Peter wrote:
Can someone confirm that power factor is NOT taken into consideration
for domestic supplies? I have a feeling it isn't, but I can't find any
information on the internet. If it matters, it's a modern (5 years
old) electronic meter I have. The power factor in my house is an
average of 0.7 so depending if it's charged for or not, my bill could be
completely different.

Domestic meters only record real power...

I'll continue using the cheap **** power supplies then :-)

--
An elderly British gentleman of 83 arrived in Paris by plane. At the French
customs desk he took a few minutes to locate his passport in his carry-on
bag. 'You have been to France before, Monsieur?' the customs officer asked
sarcastically.
The elderly gentleman admitted he had been to France previously.
'Then you should know enough to 'ave your passport ready,' the customs
officer said. The elderly gentleman replied, 'The last time I was here, I
didn't have to show it.'
'Impossible! The British always have to show their passports on arrival in
France !'
The Man gave the Frenchman a long hard look. Then he quietly explained;
'Well, when I came ashore on the Beach on D-Day in 1944, I couldn't find any
****ing Frenchmen to show it to...!!

On 17/04/2014 09:41, Brian Gaff wrote:
So how does this affect actual loading of the system. Is it large enough for
them to really be losing out?

For industrial users, certainly...

I can remember that when I worked in a factory, the leccy board came
around and wanted to redistribute the soak test racks and other things to
different mains phases due to imbalance of power factor due to the method
the ssets used to get power.
It always made me wonder how, if this was so bad, why it made no difference
when they wer in peoples homes.

Domestic users are far less likely to have a PF significantly below
unity, and if they do, it tends to be down to harmonic content rather
than classical voltage current phase mismatch.


--
Cheers,

John.

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

On Thu, 17 Apr 2014 08:38:27 +0100, harryagain wrote:


"Uncle Peter" wrote in message
news
Can someone confirm that power factor is NOT taken into consideration for
domestic supplies? I have a feeling it isn't, but I can't find any
information on the internet. If it matters, it's a modern (5 years old)
electronic meter I have. The power factor in my house is an average of
0.7 so depending if it's charged for or not, my bill could be completely
different.


The very fact that you pay for kilowatt hours (Kwh) not kilovoltamps hours
(Kvah) tells you that power factor is not accounted for.
Only commercial organisations might be asked to pay for Kvah.

I know they call it kWh, but that doesn't mean that's what they charge for :-)

I wanted to make sure that what my own meters read was the same as what theirs does. My own meters show power factor, but I think the price they show is not based on that reading. It's not clear though, as one of them (newer version of the same model!!) shows kW as kW, but the other shows kW when it's actually reading kVA. For example, one might read 240V, 2A, 480W, PF 0.7. The other will read 240V, 2A, 336W, PF 0.7. I think when I watched the costs going up on the counters, they both seemed to be calculating cost from VxAxPF, despite what was shown as "kW".

--
I want to die peacefully, in my sleep, like my Uncle Bob. Not screaming in terror like his passengers...

I would imagine that in a street, the substation is even loaded as there are several houses on each phase. Also capacitive loads and inductive loads probably even out too. But the square-wave-creating switched mode power supplies cannot be evened out, so I guess that's costing them in losses in wires.


On Thu, 17 Apr 2014 09:41:07 +0100, Brian Gaff wrote:

So how does this affect actual loading of the system. Is it large enough for
them to really be losing out?
I can remember that when I worked in a factory, the leccy board came
around and wanted to redistribute the soak test racks and other things to
different mains phases due to imbalance of power factor due to the method
the ssets used to get power.
It always made me wonder how, if this was so bad, why it made no difference
when they wer in peoples homes.
Brian



--
A woman brought an old picture of her dead husband, wearing a hat, to the photographer. She wanted to know if the photographer could remove the hat from the picture.
He convinced her he could easily do that, and asked her what side of his head her husband parted his hair on.
"I forgot," she said. "But you can see that for yourself when you take off his hat."

On Thu, 17 Apr 2014 08:38:27 +0100, harryagain wrote:

"Uncle Peter" wrote in message
news
Can someone confirm that power factor is NOT taken into consideration for
domestic supplies? I have a feeling it isn't, but I can't find any
information on the internet. If it matters, it's a modern (5 years old)
electronic meter I have. The power factor in my house is an average of
0.7 so depending if it's charged for or not, my bill could be completely
different.

The very fact that you pay for kilowatt hours (Kwh) not kilovoltamps hours
(Kvah) tells you that power factor is not accounted for.
Only commercial organisations might be asked to pay for Kvah.

At work (25 years ago) we paid for kWh but were charged for MD (Maximum
Demand) peak on kVA (not kVAh). Much correcting of PF went on; especially
as, being design and manufacture of electronic assemblies, the load was
mostly fluorescent lighting and not a lot of inductive load.
--
Peter.
The gods will stay away
whilst religions hold sway

"Brian Gaff" wrote in message
...
So how does this affect actual loading of the system. Is it large enough
for them to really be losing out?
I can remember that when I worked in a factory, the leccy board came
around and wanted to redistribute the soak test racks and other things
to different mains phases due to imbalance of power factor due to the
method the ssets used to get power.
It always made me wonder how, if this was so bad, why it made no
difference when they wer in peoples homes.
Brian


The power factor is the ratio between true power (Watts) and Apparent power
(Volts x Amps)
The current lags the volts in inductuve equipment.
The power factor is also the cosine of the angle between volts and amps.
So
angle = 0, cos 0=1 (ie in phase, (resistive load) Power factor is
1/unity.

angle = 90, cos 90 = 0 (pure inductive load) Nor actually achievable in
practice.

On Thursday, 17 April 2014 01:07:25 UTC+1, Uncle Peter wrote:
Can someone confirm that power factor is NOT taken into consideration for domestic supplies? I have a feeling it isn't, but I can't find any information on the internet. If it matters, it's a modern (5 years old) electronic meter I have. The power factor in my house is an average of 0.7 so depending if it's charged for or not, my bill could be completely different.

That depends on what you think you mean by your first sentence.

Domestic meters work with true watts, not volt-amperes. AFAIR, they all explicitly indicate that they measure kWh. There is no charge for having a bad power factor; you can take as many amps as you want at no cost, providing that your current and voltage waveforms are orthogonal. Except in principle that the amps must not be more than the supply rating and in practice that the amps must not blow the fuse. And if they ever find that you are doing something intentionally unreasonable, they'll make sure that you suffer for it, somehow.

If you have Economy 7 or Economy 10, and use that to control storage or immersion heaters, your power factor will improve while the heaters are active..

The supplier will not care about your domestic power factor as such; it is the total reactive volt-amperes that you take which might concern them.

Your non-zero power factor is *most* unlikely to be compensated by opposing contributions from neighbours. But the actual supplier (the operator of the street wires and transformers) will know the likely overall power factor of a residential street, and can fit compensating reactances if beneficial enough.

Your single-phase supply will of course be an unbalanced load contribution for the street's three-phase supply; but your neighbours on different phases will on average restore the balance sufficiently.

For businesses of sufficient size, both power and power factor can be taken into account in derermining the electricity bill, and/or a business can be compelled or persuaded to improve its power factor.

You might consider searching http://www.legislation.gov.uk for "kilowatt hour" or similar, etc.

I write as one who for some years was concerned with the non-domestic measurement of UK AC power.

--
SL

"Uncle Peter" wrote in message
news
On Thu, 17 Apr 2014 08:38:27 +0100, harryagain
wrote:


"Uncle Peter" wrote in message
news
Can someone confirm that power factor is NOT taken into consideration
for
domestic supplies? I have a feeling it isn't, but I can't find any
information on the internet. If it matters, it's a modern (5 years
old)
electronic meter I have. The power factor in my house is an average of
0.7 so depending if it's charged for or not, my bill could be completely
different.


The very fact that you pay for kilowatt hours (Kwh) not kilovoltamps
hours
(Kvah) tells you that power factor is not accounted for.
Only commercial organisations might be asked to pay for Kvah.

I know they call it kWh, but that doesn't mean that's what they charge for
:-)

I wanted to make sure that what my own meters read was the same as what
theirs does. My own meters show power factor, but I think the price they
show is not based on that reading. It's not clear though, as one of them
(newer version of the same model!!) shows kW as kW, but the other shows kW
when it's actually reading kVA. For example, one might read 240V, 2A,
480W, PF 0.7. The other will read 240V, 2A, 336W, PF 0.7. I think when I
watched the costs going up on the counters, they both seemed to be
calculating cost from VxAxPF, despite what was shown as "kW".


Volts x Amps x power factor IS watts by definition.

Power factor IS the ratio between watts and VoltsxAmps.

Watts/voltsxamps = Power Factor.

John Rumm writes:

On 17/04/2014 01:07, Uncle Peter wrote:
Can someone confirm that power factor is NOT taken into consideration
for domestic supplies? I have a feeling it isn't, but I can't find any
information on the internet. If it matters, it's a modern (5 years
old) electronic meter I have. The power factor in my house is an
average of 0.7 so depending if it's charged for or not, my bill could be
completely different.

Domestic meters only record real power...

But an old coin meter installed by the husband of a relative in the
boarding house he used to run charged for an inductive load. Quite
generously.

As I found out on a trip back to Scotland while still living in Canada.

I had plugged in a 3.5 KW autotransformer (needed 'cos I planned to use
110V power tools as soon as tenants left a flat which I'd rented out).

With no transformer load to speak of, the meter needed repeated feeding!

It now has a 10uF 250VAC capacitor to correct the power factor (also
stops it from tripping MCBs during power on).

--
Windmill, Use t m i l l
J.R.R. Tolkien:- @ S c o t s h o m e . c o m
All that is gold does not glister / Not all who wander are lost

On 17/04/2014 18:25, harryagain wrote:
"Brian Gaff" wrote in message
...
So how does this affect actual loading of the system. Is it large enough
for them to really be losing out?
I can remember that when I worked in a factory, the leccy board came
around and wanted to redistribute the soak test racks and other things
to different mains phases due to imbalance of power factor due to the
method the ssets used to get power.
It always made me wonder how, if this was so bad, why it made no
difference when they wer in peoples homes.
Brian


The power factor is the ratio between true power (Watts) and Apparent power
(Volts x Amps)
The current lags the volts in inductuve equipment.
The power factor is also the cosine of the angle between volts and amps.
So
angle = 0, cos 0=1 (ie in phase, (resistive load) Power factor is
1/unity.

angle = 90, cos 90 = 0 (pure inductive load) Nor actually achievable in
practice.

True, but not usually that applicable to non unity domestic loads in
this day and age...


--
Cheers,

John.

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

On Thu, 17 Apr 2014 16:14:02 +0100, PeterC wrote:

On Thu, 17 Apr 2014 08:38:27 +0100, harryagain wrote:

"Uncle Peter" wrote in message
news
Can someone confirm that power factor is NOT taken into consideration for
domestic supplies? I have a feeling it isn't, but I can't find any
information on the internet. If it matters, it's a modern (5 years old)
electronic meter I have. The power factor in my house is an average of
0.7 so depending if it's charged for or not, my bill could be completely
different.

The very fact that you pay for kilowatt hours (Kwh) not kilovoltamps hours
(Kvah) tells you that power factor is not accounted for.
Only commercial organisations might be asked to pay for Kvah.

At work (25 years ago) we paid for kWh but were charged for MD (Maximum
Demand) peak on kVA (not kVAh). Much correcting of PF went on; especially
as, being design and manufacture of electronic assemblies, the load was
mostly fluorescent lighting and not a lot of inductive load.

I worked in a school which had a capacitor bank. Not sure why, I can't see most of their loads being inductive. Maybe it was from back when they had inductive ballasts on the lighting. Probably nobody thought to check if it's still set right.

--
How does a man know when his wife is losing interest?
When her favorite sexual position is next door.

On Thu, 17 Apr 2014 18:31:28 +0100, wrote:

On Thursday, 17 April 2014 01:07:25 UTC+1, Uncle Peter wrote:
Can someone confirm that power factor is NOT taken into consideration for domestic supplies? I have a feeling it isn't, but I can't find any information on the internet. If it matters, it's a modern (5 years old) electronic meter I have. The power factor in my house is an average of 0.7 so depending if it's charged for or not, my bill could be completely different.

That depends on what you think you mean by your first sentence.

Domestic meters work with true watts, not volt-amperes. AFAIR, they all explicitly indicate that they measure kWh. There is no charge for having a bad power factor; you can take as many amps as you want at no cost, providing that your current and voltage waveforms are orthogonal. Except in principle that the amps must not be more than the supply rating and in practice that the amps must not blow the fuse. And if they ever find that you are doing something intentionally unreasonable, they'll make sure that you suffer for it, somehow.

Thanks, that's the answer I was looking for. Although does that also apply when taking power off the peaks of the waveform for ****ty switch mode supplies?

If you have Economy 7 or Economy 10, and use that to control storage or immersion heaters, your power factor will improve while the heaters are active.

Nope, gas. Although I rarely use it.

The supplier will not care about your domestic power factor as such; it is the total reactive volt-amperes that you take which might concern them.

Your non-zero power factor is *most* unlikely to be compensated by opposing contributions from neighbours. But the actual supplier (the operator of the street wires and transformers) will know the likely overall power factor of a residential street, and can fit compensating reactances if beneficial enough.

Your single-phase supply will of course be an unbalanced load contribution for the street's three-phase supply; but your neighbours on different phases will on average restore the balance sufficiently.

Maybe not, I use a lot more power than most. Can phases cross over with substations? Or is each one seperate right back to the power station? What I mean is.... is there such a thing as a transformer which takes 3 phases in the primary, and gives three phases in the secondary, but you can draw more from one phase on the output and put more in on a different phase on the input?

--
Why are there 5 syllables in the word "monosyllabic"?

On Thu, 17 Apr 2014 18:31:48 +0100, harryagain wrote:


"Uncle Peter" wrote in message
news
On Thu, 17 Apr 2014 08:38:27 +0100, harryagain
wrote:


"Uncle Peter" wrote in message
news Can someone confirm that power factor is NOT taken into consideration
for
domestic supplies? I have a feeling it isn't, but I can't find any
information on the internet. If it matters, it's a modern (5 years
old)
electronic meter I have. The power factor in my house is an average of
0.7 so depending if it's charged for or not, my bill could be completely
different.


The very fact that you pay for kilowatt hours (Kwh) not kilovoltamps
hours
(Kvah) tells you that power factor is not accounted for.
Only commercial organisations might be asked to pay for Kvah.

I know they call it kWh, but that doesn't mean that's what they charge for
:-)

I wanted to make sure that what my own meters read was the same as what
theirs does. My own meters show power factor, but I think the price they
show is not based on that reading. It's not clear though, as one of them
(newer version of the same model!!) shows kW as kW, but the other shows kW
when it's actually reading kVA. For example, one might read 240V, 2A,
480W, PF 0.7. The other will read 240V, 2A, 336W, PF 0.7. I think when I
watched the costs going up on the counters, they both seemed to be
calculating cost from VxAxPF, despite what was shown as "kW".


Volts x Amps x power factor IS watts by definition.

Power factor IS the ratio between watts and VoltsxAmps.

Watts/voltsxamps = Power Factor.

Yes, I know. So one of my meters is incorrect (I think it's just the kW display is actually showing kVA, calculating the cost seems correct - based on kW, not kVA). This one: 240V, 2A, 480W, PF 0.7.

--
History teaches us that no other cause has brought more death than the word of god. -- Giulian Buzila

"Uncle Peter" wrote in message
news
On Thu, 17 Apr 2014 18:31:28 +0100, wrote:

On Thursday, 17 April 2014 01:07:25 UTC+1, Uncle Peter wrote:
Can someone confirm that power factor is NOT taken into consideration
for domestic supplies? I have a feeling it isn't, but I can't find any
information on the internet. If it matters, it's a modern (5 years
old) electronic meter I have. The power factor in my house is an
average of 0.7 so depending if it's charged for or not, my bill could be
completely different.

That depends on what you think you mean by your first sentence.

Domestic meters work with true watts, not volt-amperes. AFAIR, they all
explicitly indicate that they measure kWh. There is no charge for having
a bad power factor; you can take as many amps as you want at no cost,
providing that your current and voltage waveforms are orthogonal. Except
in principle that the amps must not be more than the supply rating and in
practice that the amps must not blow the fuse. And if they ever find
that you are doing something intentionally unreasonable, they'll make
sure that you suffer for it, somehow.

Thanks, that's the answer I was looking for. Although does that also
apply when taking power off the peaks of the waveform for ****ty switch
mode supplies?

If you have Economy 7 or Economy 10, and use that to control storage or
immersion heaters, your power factor will improve while the heaters are
active.

Nope, gas. Although I rarely use it.

The supplier will not care about your domestic power factor as such; it
is the total reactive volt-amperes that you take which might concern
them.

Your non-zero power factor is *most* unlikely to be compensated by
opposing contributions from neighbours. But the actual supplier (the
operator of the street wires and transformers) will know the likely
overall power factor of a residential street, and can fit compensating
reactances if beneficial enough.

Your single-phase supply will of course be an unbalanced load
contribution for the street's three-phase supply; but your neighbours on
different phases will on average restore the balance sufficiently.

Maybe not, I use a lot more power than most. Can phases cross over with
substations? Or is each one seperate right back to the power station?
What I mean is.... is there such a thing as a transformer which takes 3
phases in the primary, and gives three phases in the secondary, but you
can draw more from one phase on the output and put more in on a different
phase on the input?


There are both three phase and single phase transformers.
Large load usually have three phases in order to distribut the load equally
over the phases as far as is possible.

The high voltage side is isolated from the low voltage side.

The naming/colouring of the phases is purely arbitary, only the "rotation"
of the phases is important.

If a load is unbalanced (ie not equally distrtributed between the phases, it
results in both phase shifts and unequal voltages appearing between phases.

In article ,
"Uncle Peter" writes:
On Thu, 17 Apr 2014 18:31:28 +0100, wrote:

On Thursday, 17 April 2014 01:07:25 UTC+1, Uncle Peter wrote:
Can someone confirm that power factor is NOT taken into consideration for domestic supplies? I have a feeling it isn't, but I can't find any information on the internet. If it matters, it's a modern (5 years old) electronic meter I have. The power factor in my house is an average of 0.7 so depending if it's charged for or not, my bill could be completely different.

That depends on what you think you mean by your first sentence.

Domestic meters work with true watts, not volt-amperes. AFAIR, they all explicitly indicate that they measure kWh. There is no charge for having a bad power factor; you can take as many amps as you want at no cost, providing that your current and voltage waveforms are orthogonal. Except in principle that the amps must not be more than the supply rating and in practice that the amps must not blow the fuse. And if they ever find that you are doing something intentionally unreasonable, they'll make sure that you suffer for it, somehow.

Thanks, that's the answer I was looking for. Although does that also apply when taking power off the peaks of the waveform for ****ty switch mode supplies?

Yes. They generate 3rd-harmonic distortion, which can be bad in large
quantities because it adds together in the neutral line, rather than
canceling out between phases.

If you have Economy 7 or Economy 10, and use that to control storage or immersion heaters, your power factor will improve while the heaters are active.

Nope, gas. Although I rarely use it.

The supplier will not care about your domestic power factor as such; it is the total reactive volt-amperes that you take which might concern them.

Your non-zero power factor is *most* unlikely to be compensated by opposing contributions from neighbours. But the actual supplier (the operator of the street wires and transformers) will know the likely overall power factor of a residential street, and can fit compensating reactances if beneficial enough.

Your single-phase supply will of course be an unbalanced load contribution for the street's three-phase supply; but your neighbours on different phases will on average restore the balance sufficiently.

Maybe not, I use a lot more power than most. Can phases cross over with substations? Or is each one seperate right back to the power station? What I mean is.... is there such a thing as a transformer which takes 3 phases in the primary, and gives three phases in the secondary, but you can draw more from one phase on the output and put more in on a different phase on the input?

The final step-down transformer is a delta-star configuration, as there
are no neutral conductors in the supply network until you step down to
240V. A high load on one of the 240V phases becomes a not so high load
on two of the three phases supplying the final stepdown transformer, so
you can see that your one-phase load is already being smoothed as you
work back up the supply chain.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Fri, 18 Apr 2014 10:44:39 +0100, Andrew Gabriel wrote:

In article ,
"Uncle Peter" writes:
On Thu, 17 Apr 2014 18:31:28 +0100, wrote:

On Thursday, 17 April 2014 01:07:25 UTC+1, Uncle Peter wrote:
Can someone confirm that power factor is NOT taken into consideration for domestic supplies? I have a feeling it isn't, but I can't find any information on the internet. If it matters, it's a modern (5 years old) electronic meter I have. The power factor in my house is an average of 0.7 so depending if it's charged for or not, my bill could be completely different.

That depends on what you think you mean by your first sentence.

Domestic meters work with true watts, not volt-amperes. AFAIR, they all explicitly indicate that they measure kWh. There is no charge for having a bad power factor; you can take as many amps as you want at no cost, providing that your current and voltage waveforms are orthogonal. Except in principle that the amps must not be more than the supply rating and in practice that the amps must not blow the fuse. And if they ever find that you are doing something intentionally unreasonable, they'll make sure that you suffer for it, somehow.

Thanks, that's the answer I was looking for. Although does that also apply when taking power off the peaks of the waveform for ****ty switch mode supplies?

Yes. They generate 3rd-harmonic distortion, which can be bad in large
quantities because it adds together in the neutral line, rather than
canceling out between phases.

And I guess there's no way to cancel a harmonic like you can shift normal PF with a capacitor.

If you have Economy 7 or Economy 10, and use that to control storage or immersion heaters, your power factor will improve while the heaters are active.

Nope, gas. Although I rarely use it.

The supplier will not care about your domestic power factor as such; it is the total reactive volt-amperes that you take which might concern them.

Your non-zero power factor is *most* unlikely to be compensated by opposing contributions from neighbours. But the actual supplier (the operator of the street wires and transformers) will know the likely overall power factor of a residential street, and can fit compensating reactances if beneficial enough.

Your single-phase supply will of course be an unbalanced load contribution for the street's three-phase supply; but your neighbours on different phases will on average restore the balance sufficiently.

Maybe not, I use a lot more power than most. Can phases cross over with substations? Or is each one seperate right back to the power station? What I mean is.... is there such a thing as a transformer which takes 3 phases in the primary, and gives three phases in the secondary, but you can draw more from one phase on the output and put more in on a different phase on the input?

The final step-down transformer is a delta-star configuration, as there
are no neutral conductors in the supply network until you step down to
240V. A high load on one of the 240V phases becomes a not so high load
on two of the three phases supplying the final stepdown transformer, so
you can see that your one-phase load is already being smoothed as you
work back up the supply chain.

I see. So the only problem of uneven phase loading is locally.

--
You can lead a man to Congress . . .
.. . . but you can't make him think.

On 18/04/14 10:44, Andrew Gabriel wrote:
In article ,
"Uncle Peter" writes:
On Thu, 17 Apr 2014 18:31:28 +0100, wrote:

On Thursday, 17 April 2014 01:07:25 UTC+1, Uncle Peter wrote:
Can someone confirm that power factor is NOT taken into consideration for domestic supplies? I have a feeling it isn't, but I can't find any information on the internet. If it matters, it's a modern (5 years old) electronic meter I have. The power factor in my house is an average of 0.7 so depending if it's charged for or not, my bill could be completely different.

That depends on what you think you mean by your first sentence.

Domestic meters work with true watts, not volt-amperes. AFAIR, they all explicitly indicate that they measure kWh. There is no charge for having a bad power factor; you can take as many amps as you want at no cost, providing that your current and voltage waveforms are orthogonal. Except in principle that the amps must not be more than the supply rating and in practice that the amps must not blow the fuse. And if they ever find that you are doing something intentionally unreasonable, they'll make sure that you suffer for it, somehow.

Thanks, that's the answer I was looking for. Although does that also apply when taking power off the peaks of the waveform for ****ty switch mode supplies?

Yes. They generate 3rd-harmonic distortion, which can be bad in large
quantities because it adds together in the neutral line, rather than
canceling out between phases.

If you have Economy 7 or Economy 10, and use that to control storage or immersion heaters, your power factor will improve while the heaters are active.

Nope, gas. Although I rarely use it.

The supplier will not care about your domestic power factor as such; it is the total reactive volt-amperes that you take which might concern them.

Your non-zero power factor is *most* unlikely to be compensated by opposing contributions from neighbours. But the actual supplier (the operator of the street wires and transformers) will know the likely overall power factor of a residential street, and can fit compensating reactances if beneficial enough.

Your single-phase supply will of course be an unbalanced load contribution for the street's three-phase supply; but your neighbours on different phases will on average restore the balance sufficiently.

Maybe not, I use a lot more power than most. Can phases cross over with substations? Or is each one seperate right back to the power station? What I mean is.... is there such a thing as a transformer which takes 3 phases in the primary, and gives three phases in the secondary, but you can draw more from one phase on the output and put more in on a different phase on the input?

The final step-down transformer is a delta-star configuration,

Not here it ain't. Nor any of the pole mounted transformers on the local
11KV overheads. One phase partial deltas.

Star-delta is not a configurations that exists in the real world either.
Its one or the other.

Its hard to see how you can supply a single phase from three phases
anyway. A single phase is always the result of the difference between
two phases.

You cant extract a single phase from a star connection anyway. A star
connected load implicitly is a three phase load.




as there
are no neutral conductors in the supply network until you step down to
240V. A high load on one of the 240V phases becomes a not so high load
on two of the three phases supplying the final stepdown transformer, so
you can see that your one-phase load is already being smoothed as you
work back up the supply chain.



--
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 Fri, 18 Apr 2014 12:16:43 +0100, The Natural Philosopher wrote:

On 18/04/14 10:44, Andrew Gabriel wrote:
In article ,
"Uncle Peter" writes:
On Thu, 17 Apr 2014 18:31:28 +0100, wrote:

On Thursday, 17 April 2014 01:07:25 UTC+1, Uncle Peter wrote:
Can someone confirm that power factor is NOT taken into consideration for domestic supplies? I have a feeling it isn't, but I can't find any information on the internet. If it matters, it's a modern (5 years old) electronic meter I have. The power factor in my house is an average of 0.7 so depending if it's charged for or not, my bill could be completely different.

That depends on what you think you mean by your first sentence.

Domestic meters work with true watts, not volt-amperes. AFAIR, they all explicitly indicate that they measure kWh. There is no charge for having a bad power factor; you can take as many amps as you want at no cost, providing that your current and voltage waveforms are orthogonal. Except in principle that the amps must not be more than the supply rating and in practice that the amps must not blow the fuse. And if they ever find that you are doing something intentionally unreasonable, they'll make sure that you suffer for it, somehow.

Thanks, that's the answer I was looking for. Although does that also apply when taking power off the peaks of the waveform for ****ty switch mode supplies?

Yes. They generate 3rd-harmonic distortion, which can be bad in large
quantities because it adds together in the neutral line, rather than
canceling out between phases.

If you have Economy 7 or Economy 10, and use that to control storage or immersion heaters, your power factor will improve while the heaters are active.

Nope, gas. Although I rarely use it.

The supplier will not care about your domestic power factor as such; it is the total reactive volt-amperes that you take which might concern them.

Your non-zero power factor is *most* unlikely to be compensated by opposing contributions from neighbours. But the actual supplier (the operator of the street wires and transformers) will know the likely overall power factor of a residential street, and can fit compensating reactances if beneficial enough.

Your single-phase supply will of course be an unbalanced load contribution for the street's three-phase supply; but your neighbours on different phases will on average restore the balance sufficiently.

Maybe not, I use a lot more power than most. Can phases cross over with substations? Or is each one seperate right back to the power station? What I mean is.... is there such a thing as a transformer which takes 3 phases in the primary, and gives three phases in the secondary, but you can draw more from one phase on the output and put more in on a different phase on the input?

The final step-down transformer is a delta-star configuration,

Not here it ain't. Nor any of the pole mounted transformers on the local
11KV overheads. One phase partial deltas.

Star-delta is not a configurations that exists in the real world either.
Its one or the other.

Its hard to see how you can supply a single phase from three phases
anyway. A single phase is always the result of the difference between
two phases.

I could have a three phase generator with the neutral grounded, and only supply one phase to a load. It would be bad for the generator bearings though I would think.

--
Women are not served here. You have to bring your own.

"The Natural Philosopher" wrote in message
...
On 18/04/14 10:44, Andrew Gabriel wrote:
In article ,
"Uncle Peter" writes:
On Thu, 17 Apr 2014 18:31:28 +0100, wrote:

On Thursday, 17 April 2014 01:07:25 UTC+1, Uncle Peter wrote:
Can someone confirm that power factor is NOT taken into consideration
for domestic supplies? I have a feeling it isn't, but I can't find
any information on the internet. If it matters, it's a modern (5
years old) electronic meter I have. The power factor in my house is
an average of 0.7 so depending if it's charged for or not, my bill
could be completely different.

That depends on what you think you mean by your first sentence.

Domestic meters work with true watts, not volt-amperes. AFAIR, they
all explicitly indicate that they measure kWh. There is no charge for
having a bad power factor; you can take as many amps as you want at no
cost, providing that your current and voltage waveforms are orthogonal.
Except in principle that the amps must not be more than the supply
rating and in practice that the amps must not blow the fuse. And if
they ever find that you are doing something intentionally unreasonable,
they'll make sure that you suffer for it, somehow.

Thanks, that's the answer I was looking for. Although does that also
apply when taking power off the peaks of the waveform for ****ty switch
mode supplies?

Yes. They generate 3rd-harmonic distortion, which can be bad in large
quantities because it adds together in the neutral line, rather than
canceling out between phases.

If you have Economy 7 or Economy 10, and use that to control storage or
immersion heaters, your power factor will improve while the heaters are
active.

Nope, gas. Although I rarely use it.

The supplier will not care about your domestic power factor as such; it
is the total reactive volt-amperes that you take which might concern
them.

Your non-zero power factor is *most* unlikely to be compensated by
opposing contributions from neighbours. But the actual supplier (the
operator of the street wires and transformers) will know the likely
overall power factor of a residential street, and can fit compensating
reactances if beneficial enough.

Your single-phase supply will of course be an unbalanced load
contribution for the street's three-phase supply; but your neighbours
on different phases will on average restore the balance sufficiently.

Maybe not, I use a lot more power than most. Can phases cross over with
substations? Or is each one seperate right back to the power station?
What I mean is.... is there such a thing as a transformer which takes 3
phases in the primary, and gives three phases in the secondary, but you
can draw more from one phase on the output and put more in on a
different phase on the input?

The final step-down transformer is a delta-star configuration,

Not here it ain't. Nor any of the pole mounted transformers on the local
11KV overheads. One phase partial deltas.

Star-delta is not a configurations that exists in the real world either.
Its one or the other.


All our three phase transformers in the UK reducing from medium/high to low
voltage are star delta configuration.
The primary winding is delta (or mesh) and the secondary winding is star.

The only exceptions are for special purposes,

On Fri, 18 Apr 2014 17:32:24 +0100, harryagain wrote:


"The Natural Philosopher" wrote in message
...
On 18/04/14 10:44, Andrew Gabriel wrote:
In article ,
"Uncle Peter" writes:
On Thu, 17 Apr 2014 18:31:28 +0100, wrote:

On Thursday, 17 April 2014 01:07:25 UTC+1, Uncle Peter wrote:


That depends on what you think you mean by your first sentence.

Domestic meters work with true watts, not volt-amperes. AFAIR, they
all explicitly indicate that they measure kWh. There is no charge for
having a bad power factor; you can take as many amps as you want at no
cost, providing that your current and voltage waveforms are orthogonal.
Except in principle that the amps must not be more than the supply
rating and in practice that the amps must not blow the fuse. And if
they ever find that you are doing something intentionally unreasonable,
they'll make sure that you suffer for it, somehow.

Thanks, that's the answer I was looking for. Although does that also
apply when taking power off the peaks of the waveform for ****ty switch
mode supplies?

Yes. They generate 3rd-harmonic distortion, which can be bad in large
quantities because it adds together in the neutral line, rather than
canceling out between phases.

If you have Economy 7 or Economy 10, and use that to control storage or
immersion heaters, your power factor will improve while the heaters are
active.

Nope, gas. Although I rarely use it.

The supplier will not care about your domestic power factor as such; it
is the total reactive volt-amperes that you take which might concern
them.

Your non-zero power factor is *most* unlikely to be compensated by
opposing contributions from neighbours. But the actual supplier (the
operator of the street wires and transformers) will know the likely
overall power factor of a residential street, and can fit compensating
reactances if beneficial enough.

Your single-phase supply will of course be an unbalanced load
contribution for the street's three-phase supply; but your neighbours
on different phases will on average restore the balance sufficiently.

Maybe not, I use a lot more power than most. Can phases cross over with
substations? Or is each one seperate right back to the power station?
What I mean is.... is there such a thing as a transformer which takes 3
phases in the primary, and gives three phases in the secondary, but you
can draw more from one phase on the output and put more in on a
different phase on the input?

The final step-down transformer is a delta-star configuration,

Not here it ain't. Nor any of the pole mounted transformers on the local
11KV overheads. One phase partial deltas.

Star-delta is not a configurations that exists in the real world either.
Its one or the other.


All our three phase transformers in the UK reducing from medium/high to low
voltage are star delta configuration.
The primary winding is delta (or mesh) and the secondary winding is star.

Like this? http://electrical-engineering-portal...ction-overview

How are the windings PHYSICALLY arranged?

--
If the Pope goes #2, does that make it "Holy ****"?

In article ,
"Uncle Peter" writes:
On Fri, 18 Apr 2014 17:32:24 +0100, harryagain wrote:


"The Natural Philosopher" wrote in message
...
On 18/04/14 10:44, Andrew Gabriel wrote:
In article ,
"Uncle Peter" writes:
On Thu, 17 Apr 2014 18:31:28 +0100, wrote:

On Thursday, 17 April 2014 01:07:25 UTC+1, Uncle Peter wrote:


That depends on what you think you mean by your first sentence.

Domestic meters work with true watts, not volt-amperes. AFAIR, they
all explicitly indicate that they measure kWh. There is no charge for
having a bad power factor; you can take as many amps as you want at no
cost, providing that your current and voltage waveforms are orthogonal.
Except in principle that the amps must not be more than the supply
rating and in practice that the amps must not blow the fuse. And if
they ever find that you are doing something intentionally unreasonable,
they'll make sure that you suffer for it, somehow.

Thanks, that's the answer I was looking for. Although does that also
apply when taking power off the peaks of the waveform for ****ty switch
mode supplies?

Yes. They generate 3rd-harmonic distortion, which can be bad in large
quantities because it adds together in the neutral line, rather than
canceling out between phases.

If you have Economy 7 or Economy 10, and use that to control storage or
immersion heaters, your power factor will improve while the heaters are
active.

Nope, gas. Although I rarely use it.

The supplier will not care about your domestic power factor as such; it
is the total reactive volt-amperes that you take which might concern
them.

Your non-zero power factor is *most* unlikely to be compensated by
opposing contributions from neighbours. But the actual supplier (the
operator of the street wires and transformers) will know the likely
overall power factor of a residential street, and can fit compensating
reactances if beneficial enough.

Your single-phase supply will of course be an unbalanced load
contribution for the street's three-phase supply; but your neighbours
on different phases will on average restore the balance sufficiently.

Maybe not, I use a lot more power than most. Can phases cross over with
substations? Or is each one seperate right back to the power station?
What I mean is.... is there such a thing as a transformer which takes 3
phases in the primary, and gives three phases in the secondary, but you
can draw more from one phase on the output and put more in on a
different phase on the input?

The final step-down transformer is a delta-star configuration,

Not here it ain't. Nor any of the pole mounted transformers on the local
11KV overheads. One phase partial deltas.

Star-delta is not a configurations that exists in the real world either.
Its one or the other.


All our three phase transformers in the UK reducing from medium/high to low
voltage are star delta configuration.
The primary winding is delta (or mesh) and the secondary winding is star.

Like this? http://electrical-engineering-portal...ction-overview

Yes.

For single phase, you have just a third of it - a single transformer
with primary between two HV phases, and secondary with the neutral
side grounded. Again, the load on that single-phase secondary is
spread between two of the HV phases.

How are the windings PHYSICALLY arranged?

Varies with size and manufacture.
Search for pictures of power transformers.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 18/04/2014 11:01, Uncle Peter wrote:
On Fri, 18 Apr 2014 10:44:39 +0100, Andrew Gabriel
wrote:


Thanks, that's the answer I was looking for. Although does that also
apply when taking power off the peaks of the waveform for ****ty
switch mode supplies?

Yes. They generate 3rd-harmonic distortion, which can be bad in large
quantities because it adds together in the neutral line, rather than
canceling out between phases.

And I guess there's no way to cancel a harmonic like you can shift
normal PF with a capacitor.

Its not easy once the harmonic content has been created. The PFC built
into modern SMPSUs will suppress the creation of it by spreading the
duration of the current draw by the PSU - rather than just concentrating
it at the peak of the voltage waveform.


--
Cheers,

John.

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

On Sat, 19 Apr 2014 00:43:30 +0100, John Rumm wrote:

On 18/04/2014 11:01, Uncle Peter wrote:
On Fri, 18 Apr 2014 10:44:39 +0100, Andrew Gabriel
wrote:


Thanks, that's the answer I was looking for. Although does that also
apply when taking power off the peaks of the waveform for ****ty
switch mode supplies?

Yes. They generate 3rd-harmonic distortion, which can be bad in large
quantities because it adds together in the neutral line, rather than
canceling out between phases.

And I guess there's no way to cancel a harmonic like you can shift
normal PF with a capacitor.

Its not easy once the harmonic content has been created. The PFC built
into modern SMPSUs will suppress the creation of it by spreading the
duration of the current draw by the PSU - rather than just concentrating
it at the peak of the voltage waveform.

These are modern SMPSUs, just very cheap ones (about half the price).

--
Britney Spears is pregnant. She plans to breast feed.
In other words, the child will have an abundant supply of artificial milk.

On 19/04/2014 01:09, Uncle Peter wrote:
On Sat, 19 Apr 2014 00:43:30 +0100, John Rumm
wrote:

On 18/04/2014 11:01, Uncle Peter wrote:
On Fri, 18 Apr 2014 10:44:39 +0100, Andrew Gabriel
wrote:


Thanks, that's the answer I was looking for. Although does that also
apply when taking power off the peaks of the waveform for ****ty
switch mode supplies?

Yes. They generate 3rd-harmonic distortion, which can be bad in large
quantities because it adds together in the neutral line, rather than
canceling out between phases.

And I guess there's no way to cancel a harmonic like you can shift
normal PF with a capacitor.

Its not easy once the harmonic content has been created. The PFC built
into modern SMPSUs will suppress the creation of it by spreading the
duration of the current draw by the PSU - rather than just concentrating
it at the peak of the voltage waveform.

These are modern SMPSUs, just very cheap ones (about half the price).

Anything over 75W is required to have PFC these days...



--
Cheers,

John.

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

In article ,
John Rumm writes:
On 19/04/2014 01:09, Uncle Peter wrote:
On Sat, 19 Apr 2014 00:43:30 +0100, John Rumm
wrote:

On 18/04/2014 11:01, Uncle Peter wrote:
On Fri, 18 Apr 2014 10:44:39 +0100, Andrew Gabriel
wrote:


Thanks, that's the answer I was looking for. Although does that also
apply when taking power off the peaks of the waveform for ****ty
switch mode supplies?

Yes. They generate 3rd-harmonic distortion, which can be bad in large
quantities because it adds together in the neutral line, rather than
canceling out between phases.

And I guess there's no way to cancel a harmonic like you can shift
normal PF with a capacitor.

Its not easy once the harmonic content has been created. The PFC built
into modern SMPSUs will suppress the creation of it by spreading the
duration of the current draw by the PSU - rather than just concentrating
it at the peak of the voltage waveform.

These are modern SMPSUs, just very cheap ones (about half the price).

Anything over 75W is required to have PFC these days...

and for electronic ballasts for lighting, anything over 25W, including
CFLs with integral ballasts.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Sat, 19 Apr 2014 07:12:25 +0100, John Rumm wrote:

On 19/04/2014 01:09, Uncle Peter wrote:
On Sat, 19 Apr 2014 00:43:30 +0100, John Rumm
wrote:

On 18/04/2014 11:01, Uncle Peter wrote:
On Fri, 18 Apr 2014 10:44:39 +0100, Andrew Gabriel
wrote:




Yes. They generate 3rd-harmonic distortion, which can be bad in large
quantities because it adds together in the neutral line, rather than
canceling out between phases.

And I guess there's no way to cancel a harmonic like you can shift
normal PF with a capacitor.

Its not easy once the harmonic content has been created. The PFC built
into modern SMPSUs will suppress the creation of it by spreading the
duration of the current draw by the PSU - rather than just concentrating
it at the peak of the voltage waveform.

These are modern SMPSUs, just very cheap ones (about half the price).

Anything over 75W is required to have PFC these days...

They have passive PFC. But that's ****. It's still got a PF of 0.67 measured by a few meters. Verified by 2kW of it heats up the wires as much as 3kW of heater.

--
The modest young lass had just purchased some lingerie and asked if she might have the sentence "If you can read this, you're too damned close" embroidered on her panties and bra.
"Yes madam," said the clerk. "I'm quite certain that could be done. Would you prefer block or script letters ?"
"Braille," she replied.

On Sat, 19 Apr 2014 09:24:40 +0100, Andrew Gabriel wrote:

In article ,
John Rumm writes:
On 19/04/2014 01:09, Uncle Peter wrote:
On Sat, 19 Apr 2014 00:43:30 +0100, John Rumm
wrote:

On 18/04/2014 11:01, Uncle Peter wrote:
On Fri, 18 Apr 2014 10:44:39 +0100, Andrew Gabriel
wrote:




And I guess there's no way to cancel a harmonic like you can shift
normal PF with a capacitor.

Its not easy once the harmonic content has been created. The PFC built
into modern SMPSUs will suppress the creation of it by spreading the
duration of the current draw by the PSU - rather than just concentrating
it at the peak of the voltage waveform.

These are modern SMPSUs, just very cheap ones (about half the price).

Anything over 75W is required to have PFC these days...

and for electronic ballasts for lighting, anything over 25W, including
CFLs with integral ballasts.

Required isn't the same as has.

--
Seen on a tap in a Finnish washroom:
To stop the drip, turn cock to right.

In article ,
"Uncle Peter" writes:
On Sat, 19 Apr 2014 09:24:40 +0100, Andrew Gabriel wrote:

In article ,
John Rumm writes:
On 19/04/2014 01:09, Uncle Peter wrote:
On Sat, 19 Apr 2014 00:43:30 +0100, John Rumm
wrote:

On 18/04/2014 11:01, Uncle Peter wrote:
On Fri, 18 Apr 2014 10:44:39 +0100, Andrew Gabriel
wrote:




And I guess there's no way to cancel a harmonic like you can shift
normal PF with a capacitor.

Its not easy once the harmonic content has been created. The PFC built
into modern SMPSUs will suppress the creation of it by spreading the
duration of the current draw by the PSU - rather than just concentrating
it at the peak of the voltage waveform.

These are modern SMPSUs, just very cheap ones (about half the price).

Anything over 75W is required to have PFC these days...

and for electronic ballasts for lighting, anything over 25W, including
CFLs with integral ballasts.

Required isn't the same as has.

I only have one CFL over 25W (a 30W one from Homebase many years
ago - they don't do them anymore), and it does have a PF of almost 1.
This is probably also partly why most consumer CFL retrofit ranges
stop below 25W.

As for separate electronic ballasts, they've all been PF 0.9 for
probably a decade or more. Once the design and initial roll-out is
done, there is next to no additional cost anymore. These products
are extremely high margin anyway - the component costs are tiny
compared with the selling price.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Sat, 19 Apr 2014 11:46:23 +0100, Andrew Gabriel wrote:

In article ,
"Uncle Peter" writes:
On Sat, 19 Apr 2014 09:24:40 +0100, Andrew Gabriel wrote:

In article ,
John Rumm writes:
On 19/04/2014 01:09, Uncle Peter wrote:
On Sat, 19 Apr 2014 00:43:30 +0100, John Rumm
wrote:





These are modern SMPSUs, just very cheap ones (about half the price).

Anything over 75W is required to have PFC these days...

and for electronic ballasts for lighting, anything over 25W, including
CFLs with integral ballasts.

Required isn't the same as has.

I only have one CFL over 25W (a 30W one from Homebase many years
ago - they don't do them anymore), and it does have a PF of almost 1.
This is probably also partly why most consumer CFL retrofit ranges
stop below 25W.

Or most people don't have bulbs brighter than 100W equivalent. Mind you I've got 8 of those CFLs (under 25W) in my living room. So that's a lot more than 25W, and no PFC.

As for separate electronic ballasts, they've all been PF 0.9 for
probably a decade or more. Once the design and initial roll-out is
done, there is next to no additional cost anymore. These products
are extremely high margin anyway - the component costs are tiny
compared with the selling price.

Presumably the same is not true for PC PSUs? Only the expensive ones have proper active PFC.

--
Please do not look into laser with remaining eye.

On 19/04/14 00:43, John Rumm wrote:
On 18/04/2014 11:01, Uncle Peter wrote:
On Fri, 18 Apr 2014 10:44:39 +0100, Andrew Gabriel
wrote:


Thanks, that's the answer I was looking for. Although does that also
apply when taking power off the peaks of the waveform for ****ty
switch mode supplies?

Yes. They generate 3rd-harmonic distortion, which can be bad in large
quantities because it adds together in the neutral line, rather than
canceling out between phases.

And I guess there's no way to cancel a harmonic like you can shift
normal PF with a capacitor.

Its not easy once the harmonic content has been created. The PFC built
into modern SMPSUs will suppress the creation of it by spreading the
duration of the current draw by the PSU - rather than just concentrating
it at the peak of the voltage waveform.


In fact you can do better than that as well by not smoothing the input
(too much) so you are operating on very 'ripply' DC to generate the output.



--
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.

"Uncle Peter" wrote in message
news
On Fri, 18 Apr 2014 17:32:24 +0100, harryagain
wrote:


"The Natural Philosopher" wrote in message
...
On 18/04/14 10:44, Andrew Gabriel wrote:
In article ,
"Uncle Peter" writes:
On Thu, 17 Apr 2014 18:31:28 +0100, wrote:

On Thursday, 17 April 2014 01:07:25 UTC+1, Uncle Peter wrote:


That depends on what you think you mean by your first sentence.

Domestic meters work with true watts, not volt-amperes. AFAIR, they
all explicitly indicate that they measure kWh. There is no charge
for
having a bad power factor; you can take as many amps as you want at
no
cost, providing that your current and voltage waveforms are
orthogonal.
Except in principle that the amps must not be more than the supply
rating and in practice that the amps must not blow the fuse. And if
they ever find that you are doing something intentionally
unreasonable,
they'll make sure that you suffer for it, somehow.

Thanks, that's the answer I was looking for. Although does that also
apply when taking power off the peaks of the waveform for ****ty
switch
mode supplies?

Yes. They generate 3rd-harmonic distortion, which can be bad in large
quantities because it adds together in the neutral line, rather than
canceling out between phases.

If you have Economy 7 or Economy 10, and use that to control storage
or
immersion heaters, your power factor will improve while the heaters
are
active.

Nope, gas. Although I rarely use it.

The supplier will not care about your domestic power factor as such;
it
is the total reactive volt-amperes that you take which might concern
them.

Your non-zero power factor is *most* unlikely to be compensated by
opposing contributions from neighbours. But the actual supplier (the
operator of the street wires and transformers) will know the likely
overall power factor of a residential street, and can fit
compensating
reactances if beneficial enough.

Your single-phase supply will of course be an unbalanced load
contribution for the street's three-phase supply; but your neighbours
on different phases will on average restore the balance sufficiently.

Maybe not, I use a lot more power than most. Can phases cross over
with
substations? Or is each one seperate right back to the power station?
What I mean is.... is there such a thing as a transformer which takes
3
phases in the primary, and gives three phases in the secondary, but
you
can draw more from one phase on the output and put more in on a
different phase on the input?

The final step-down transformer is a delta-star configuration,

Not here it ain't. Nor any of the pole mounted transformers on the local
11KV overheads. One phase partial deltas.

Star-delta is not a configurations that exists in the real world either.
Its one or the other.


All our three phase transformers in the UK reducing from medium/high to
low
voltage are star delta configuration.
The primary winding is delta (or mesh) and the secondary winding is star.

Like this?
http://electrical-engineering-portal...ction-overview

How are the windings PHYSICALLY arranged?

Normally they are on three parallel limbs.
Physically parallel that is.
A primary winding and a secondary winding on each limb.
Pix here.

http://en.wikipedia.org/wiki/File:Dr...spannun g.jpg

On 19/04/2014 12:28, Uncle Peter wrote:

As for separate electronic ballasts, they've all been PF 0.9 for
probably a decade or more. Once the design and initial roll-out is
done, there is next to no additional cost anymore. These products
are extremely high margin anyway - the component costs are tiny
compared with the selling price.

Presumably the same is not true for PC PSUs? Only the expensive ones
have proper active PFC.

I just checked a few budget ones I have in the cupboard - all of them
claim to have PFC


--
Cheers,

John.

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On 19/04/2014 10:56, Uncle Peter wrote:
On Sat, 19 Apr 2014 07:12:25 +0100, John Rumm
wrote:

On 19/04/2014 01:09, Uncle Peter wrote:
On Sat, 19 Apr 2014 00:43:30 +0100, John Rumm
wrote:

On 18/04/2014 11:01, Uncle Peter wrote:
On Fri, 18 Apr 2014 10:44:39 +0100, Andrew Gabriel
wrote:




Yes. They generate 3rd-harmonic distortion, which can be bad in large
quantities because it adds together in the neutral line, rather than
canceling out between phases.

And I guess there's no way to cancel a harmonic like you can shift
normal PF with a capacitor.

Its not easy once the harmonic content has been created. The PFC built
into modern SMPSUs will suppress the creation of it by spreading the
duration of the current draw by the PSU - rather than just
concentrating
it at the peak of the voltage waveform.

These are modern SMPSUs, just very cheap ones (about half the price).

Anything over 75W is required to have PFC these days...

They have passive PFC. But that's ****. It's still got a PF of 0.67

I would not trust the plug in meters when measuring harmonic PFs

measured by a few meters. Verified by 2kW of it heats up the wires as
much as 3kW of heater.

How are you measuring the temperature and heat loss from the wires?

--
Cheers,

John.

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

On Sat, 19 Apr 2014 20:22:23 +0100, John Rumm wrote:

On 19/04/2014 10:56, Uncle Peter wrote:
On Sat, 19 Apr 2014 07:12:25 +0100, John Rumm
wrote:

On 19/04/2014 01:09, Uncle Peter wrote:
On Sat, 19 Apr 2014 00:43:30 +0100, John Rumm
wrote:

On 18/04/2014 11:01, Uncle Peter wrote:






Its not easy once the harmonic content has been created. The PFC built
into modern SMPSUs will suppress the creation of it by spreading the
duration of the current draw by the PSU - rather than just
concentrating
it at the peak of the voltage waveform.

These are modern SMPSUs, just very cheap ones (about half the price).

Anything over 75W is required to have PFC these days...

They have passive PFC. But that's ****. It's still got a PF of 0.67

I would not trust the plug in meters when measuring harmonic PFs

I also measured current with a few different meters, and the output current of the 12V DC supplies.

measured by a few meters. Verified by 2kW of it heats up the wires as
much as 3kW of heater.

How are you measuring the temperature and heat loss from the wires?

With my fingers. At 2kW, the wires are pretty warm. Adding another kW of PSUs to it would damage the wire.

--
There's been global warming since the ice age.

On Sat, 19 Apr 2014 20:19:15 +0100, John Rumm wrote:

On 19/04/2014 12:28, Uncle Peter wrote:

As for separate electronic ballasts, they've all been PF 0.9 for
probably a decade or more. Once the design and initial roll-out is
done, there is next to no additional cost anymore. These products
are extremely high margin anyway - the component costs are tiny
compared with the selling price.

Presumably the same is not true for PC PSUs? Only the expensive ones
have proper active PFC.

I just checked a few budget ones I have in the cupboard - all of them
claim to have PFC

There is passive and active. Passive probably only counteracts LC PF, not the harmonic one.

--
"Dear IRS: I would like to cancel my subscription. Please remove my name from your mailing list." -- Joe Cockler

On Sat, 19 Apr 2014 17:29:29 +0100, harryagain wrote:


"Uncle Peter" wrote in message
news
On Fri, 18 Apr 2014 17:32:24 +0100, harryagain
wrote:


"The Natural Philosopher" wrote in message
...
On 18/04/14 10:44, Andrew Gabriel wrote:
In article ,
"Uncle Peter" writes:




Yes. They generate 3rd-harmonic distortion, which can be bad in large
quantities because it adds together in the neutral line, rather than
canceling out between phases.



The final step-down transformer is a delta-star configuration,

Not here it ain't. Nor any of the pole mounted transformers on the local
11KV overheads. One phase partial deltas.

Star-delta is not a configurations that exists in the real world either.
Its one or the other.


All our three phase transformers in the UK reducing from medium/high to
low
voltage are star delta configuration.
The primary winding is delta (or mesh) and the secondary winding is star.

Like this?
http://electrical-engineering-portal...ction-overview

How are the windings PHYSICALLY arranged?

Normally they are on three parallel limbs.
Physically parallel that is.
A primary winding and a secondary winding on each limb.
Pix here.

http://en.wikipedia.org/wiki/File:Dr...spannun g.jpg

Cool, it's on wheels!

I take it the thing at the top is a cooling oil reserve?

--
You keep believing, I'll keep evolving