my friend geoff asks:
Does anybody have a view on domestic voltage stabilisers. From an engineers perspective, I cant see why they would reduce your power consumption:
1) Anything with thermostat control (eg cooker) - no effect.
2) Nearly all electronic stuff has AC to DC inverter these days - no effect
3) Motors, maybe. But this is basically your fridge and these too, being thermostatically controlled use nearly the same power, whatever the voltage.
4) Central heating pump probably would use less.

BUT if the stabiliser has losses (it will have losses) these are 24/7.

So I would expect stabilisers to be at best useless and possibly cause you to use more power than without it.

Any opinions?

George Miles wrote:
my friend geoff asks:
Does anybody have a view on domestic voltage stabilisers. From an
engineers perspective, I cant see why they would reduce your power consumption:
1) Anything with thermostat control (eg cooker) - no effect.
2) Nearly all electronic stuff has AC to DC inverter these days - no effect
3) Motors, maybe. But this is basically your fridge and these too, being
thermostatically controlled use nearly the same power, whatever the voltage.
4) Central heating pump probably would use less.

BUT if the stabiliser has losses (it will have losses) these are 24/7.

So I would expect stabilisers to be at best useless and possibly cause
you to use more power than without it.


Yes.

Any opinions?


As above. ;-) Plenty of reviews on YouTube of these snake oil devices. Try
Big Clive and €œenergy savers€�.




--
Please don't feed the trolls

On 05/06/2020 17:15, George Miles wrote:
my friend geoff asks: Does anybody have a view on domestic voltage
stabilisers. From an engineers perspective, I cant see why they
would reduce your power consumption: 1) Anything with thermostat
control (eg cooker) - no effect. 2) Nearly all electronic stuff has
AC to DC inverter these days - no effect 3) Motors, maybe. But this
is basically your fridge and these too, being thermostatically
controlled use nearly the same power, whatever the voltage. 4)
Central heating pump probably would use less.

BUT if the stabiliser has losses (it will have losses) these are
24/7.

So I would expect stabilisers to be at best useless and possibly
cause you to use more power than without it.

Any opinions?

Pure snake oil with a layer of marketing hype.

--
Regards,
Martin Brown

Thanks; I meant average power, to be more precise

On 05/06/2020 17:15, George Miles wrote:

my friend geoff asks: Does anybody have a view on domestic voltage
stabilisers. From an engineers perspective,

IMHO, fairly pointless, so you can expect someone to put them in the
wiring regs

I cant see why they
would reduce your power consumption: 1) Anything with thermostat
control (eg cooker) - no effect.

yup

2) Nearly all electronic stuff has
AC to DC inverter these days - no effect

yup

3) Motors, maybe. But this
is basically your fridge and these too, being thermostatically
controlled use nearly the same power, whatever the voltage.

Universal motors will run a bit slower and draw less current. Induction
motors will slip a bit more and compensate by drawing more current,
running hotter, and suffering a slightly shorter life.

4)
Central heating pump probably would use less.

Induction motor - so not much change, and any waste heat is dissipated
into the CH water anyway, so a very minimal reduction of costs shifting
some power consumption from electricity to gas/oil.

BUT if the stabiliser has losses (it will have losses) these are
24/7.

They are normally based on auto transformers, which reduces them a bit,
but yup.

So I would expect stabilisers to be at best useless and possibly
cause you to use more power than without it.

Any opinions?

If you were were a salesman you could probably concoct a loading
scenario that makes them save money, but harder in the real world,
especially now that many people have phased out incandescent lamps which
is one area they could make some savings, so long as you did not
compensate for the reduction in light output by turning on extra lamps
or fitting higher power lamps.



--
Cheers,

John.

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\================================================= ================/

On 05/06/2020 21:25:57, wrote:
Thanks; I meant average power, to be more precise

Please explain what you mean by 'average power'.

I pay for the energy I consume.

On Friday, 5 June 2020 17:15:53 UTC+1, George Miles wrote:
my friend geoff asks:

Does anybody have a view on domestic voltage stabilisers.

240v mains is already stable in almost every case. And yes, it's 240.


I assume you mean a voltage reducer. If so...

From an engineers perspective, I cant see why they would reduce your power consumption:
1) Anything with thermostat control (eg cooker) - no effect.

slower to heat, bit more heat loss, not much

2) Nearly all electronic stuff has AC to DC inverter these days - no effect

3) Motors, maybe. But this is basically your fridge and these too, being thermostatically controlled use nearly the same power, whatever the voltage..

fridges object to undervoltage, it tends to kill them as they stall repeatedly & overheat.

4) Central heating pump probably would use less.

yes, while increasing boiler heat loss up the chimney. Not a gain. I guess a smart pump would not be affected.


BUT if the stabiliser has losses (it will have losses) these are 24/7.

So I would expect stabilisers to be at best useless and possibly cause you to use more power than without it.

Any opinions?

Increasing voltage to lighting was useful back in the filament lamp days. Not now. It enabled me to replace 100w lamps with 60w boosted to something like 65/70w. Life fell from 1000hr to 300hr, so only for fittings with easily accessed bulbs. And not fluorescents.


NT

3) Motors, maybe. But this is basically your fridge and these too, being thermostatically controlled use nearly the same power, whatever the voltage.

You mean energy, not power.



4) Central heating pump probably would use less.

BUT if the stabiliser has losses (it will have losses) these are 24/7.

So I would expect stabilisers to be at best useless and possibly cause you to use more power than without it.

Any opinions?



--

%Profound_observation%


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

On 05/06/2020 21:25, wrote:
Thanks; I meant average power, to be more precise

aka 'energy'

--
€œA leader is best When people barely know he exists. Of a good leader,
who talks little,When his work is done, his aim fulfilled,They will say,
€œWe did this ourselves.€�

ۥ Lao Tzu, Tao Te Ching

Yes you don't get ought for nought as my gran used to say, if you are doing
something then it uses energy.
That energy is over and above the energy used by your system. Obvious one is
starting a motor with a big load. Often it is started very slowly then
brought up to speed and this to some extent can stop the equipment putting a
darned great dent in the mains voltage at start up, created due to the
heating up of the cables. Starting it slowly however and speeding it up will
still use the same or more energy, but over a longer time period, no peak in
current, just gradual increases over time.
Brian

--
----- --
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"George Miles" wrote in message
...
my friend geoff asks:
Does anybody have a view on domestic voltage stabilisers. From an engineer's
perspective, I can't see why they would reduce your power consumption:
1) Anything with thermostat control (eg cooker) - no effect.
2) Nearly all electronic stuff has AC to DC inverter these days - no effect
3) Motors, maybe. But this is basically your fridge and these too, being
thermostatically controlled use nearly the same power, whatever the voltage.
4) Central heating pump probably would use less.

BUT if the stabiliser has losses (it will have losses) these are 24/7.

So I would expect stabilisers to be at best useless and possibly cause you
to use more power than without it.

Any opinions?

The mains voltage here has been pretty variable of late. Over the last few days, following some switching round a network fault I've had varying readings from 259 to 240. Anything over 253 is deemed dangerous by northern power grid so they turned out to measure for themselves then switched network connections around that evening. I phoned the following day at midday when the voltage got up to 257 and further switching took place which took daytime volts down to 248. Not had much sun since but NPG engineers reckon my village has a lot of solar generation.

On 06/06/2020 09:58, Cynic wrote:
The mains voltage here has been pretty variable of late. Over the last few days, following some switching round a network fault I've had varying readings from 259 to 240. Anything over 253 is deemed dangerous by northern power grid so they turned out to measure for themselves then switched network connections around that evening. I phoned the following day at midday when the voltage got up to 257 and further switching took place which took daytime volts down to 248. Not had much sun since but NPG engineers reckon my village has a lot of solar generation.

yet another reason to ban solar power


--
In todays liberal progressive conflict-free education system, everyone
gets full Marx.

In article ,
Cynic wrote:
The mains voltage here has been pretty variable of late. Over the last few days, following some switching round a network fault I've had varying readings from 259 to 240. Anything over 253 is deemed dangerous by northern power grid so they turned out to measure for themselves then switched network connections around that evening. I phoned the following day at midday when the voltage got up to 257 and further switching took place which took daytime volts down to 248. Not had much sun since but NPG engineers reckon my village has a lot of solar generation.

It's not so much dangerous as illegal. 253 is the maximum permitted
voltage. (230 +10%/-6%)

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

On 05/06/2020 17:15, George Miles wrote:
my friend geoff asks:
Does anybody have a view on domestic voltage stabilisers. From an engineers perspective, I cant see why they would reduce your power consumption:
1) Anything with thermostat control (eg cooker) - no effect.
2) Nearly all electronic stuff has AC to DC inverter these days - no effect
3) Motors, maybe. But this is basically your fridge and these too, being thermostatically controlled use nearly the same power, whatever the voltage.
4) Central heating pump probably would use less.

BUT if the stabiliser has losses (it will have losses) these are 24/7.

So I would expect stabilisers to be at best useless and possibly cause you to use more power than without it.

Any opinions?


My oil boiler has an induction motor which drives the pump and the fan.
The pump has a pressure regulator so likely the pressure would remain
the same if there was a minor change in the motor speed. However the fan
would likely deliver the wrong amount of air. To little air cause the
boiler to run black as not all the oil is burnt properly. To much air,
and the hot gas is blown up the chimney instead of heating the water in
the boiler.

So in either case the boiler does not run as efficiently as it should,
not that I have ever bothered to check the voltage in the past!


--
Michael Chare

On Fri, 5 Jun 2020 09:15:48 -0700 (PDT), George Miles
wrote:

my friend geoff asks:
Does anybody have a view on domestic voltage stabilisers. From an engineer’s perspective, I can’t see why they would reduce your power consumption:
1) Anything with thermostat control (eg cooker) - no effect.
2) Nearly all electronic stuff has AC to DC inverter these days - no effect
3) Motors, maybe. But this is basically your fridge and these too, being thermostatically controlled use nearly the same power, whatever the voltage.
4) Central heating pump probably would use less.

BUT if the stabiliser has losses (it will have losses) these are 24/7.

So I would expect stabilisers to be at best useless and possibly cause you to use more power than without it.

Any opinions?

The management decided to fit one at my last office. I pointed out
that the electricity consumption comprised computer equipment (with
power supply units), fluorescent then LED lighting, two kettles and
two fridges. I pointed out to our office manager that I did not think
we would save any electricity. She thought I was probably right but
the decision had been made at a more senior level. I think it got
removed in the end but 'the management' is exercising its right of
silence on the subject.

On 06/06/2020 09:58, Cynic wrote:
The mains voltage here has been pretty variable of late. Over the last few days, following some switching round a network fault I've had varying readings from 259 to 240. Anything over 253 is deemed dangerous by northern power grid so they turned out to measure for themselves then switched network connections around that evening. I phoned the following day at midday when the voltage got up to 257 and further switching took place which took daytime volts down to 248. Not had much sun since but NPG engineers reckon my village has a lot of solar generation.


On reading this, I fished out my old Tchaibo plug-in "wattmeter"
and it showed 214 V.

Hmm. Multimeter said 240V, and after being plugged in for an hour
the Wattmeter shows 228 volts. Clearly something inside it is
drifting or changing value. Time to bin it I guess.

Does anyone else use these things ?. It was cheap anyway. Are
there more reliable (expensive) models ?.

On 06/06/2020 11:39, Michael Chare wrote:
On 05/06/2020 17:15, George Miles wrote:
my friend geoff asks:
Does anybody have a view on domestic voltage stabilisers. From an
engineers perspective, I cant see why they would reduce your power
consumption:
1) Anything with thermostat control (eg cooker) - no effect.
2) Nearly all electronic stuff has AC to DC inverter these days - no
effect
3) Motors, maybe. But this is basically your fridge and these too,
being thermostatically controlled use nearly the same power, whatever
the voltage.
4) Central heating pump probably would use less.

BUT if the stabiliser has losses (it will have losses) these are 24/7.

So I would expect stabilisers to be at best useless and possibly cause
you to use more power than without it.

Any opinions?


My oil boiler has an induction motor which drives the pump and the fan.
The pump has a pressure regulator so likely the pressure would remain
the same if there was a minor change in the motor speed. However the fan
would likely deliver the wrong amount of air. To little air cause the
boiler to run black as not all the oil is burnt properly. To much air,
and the hot gas is blown up the chimney instead of heating the water in
the boiler.

So in either case the boiler does not run as efficiently as it should,
not that I have ever bothered to check the voltage in the past!

Boiler fans are induction motor powered, so unlikely to change speed by
any significant amount on a higher voltage.


--
Cheers,

John.

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

On 06/06/2020 11:39:42, Michael Chare wrote:
On 05/06/2020 17:15, George Miles wrote:
my friend geoff asks:
Does anybody have a view on domestic voltage stabilisers. From an
engineers perspective, I cant see why they would reduce your power
consumption:
1) Anything with thermostat control (eg cooker) - no effect.
2) Nearly all electronic stuff has AC to DC inverter these days - no
effect
3) Motors, maybe. But this is basically your fridge and these too,
being thermostatically controlled use nearly the same power, whatever
the voltage.
4) Central heating pump probably would use less.

BUT if the stabiliser has losses (it will have losses) these are 24/7.

So I would expect stabilisers to be at best useless and possibly cause
you to use more power than without it.

Any opinions?


My oil boiler has an induction motor which drives the pump and the fan.

Where the speed will be a strong function of mains frequency and only
weakly dependent on precise mains voltage.

An induction motor is one of the devices where a voltage stabiliser
might reduce power consumption slightly.

On 06/06/2020 17:08, Fredxx wrote:
Where the speed will be a strong function of mains frequency and only
weakly dependent on precise mains voltage.

An induction motor is one of the devices where a voltage stabiliser
might reduce power consumption slightly.

You sure about that?

It's spinning at the same speed, driving the same load, so the output
power will be the same.

Won't it just lag the phase slightly less if the voltage is higher, and
draw slightly less current?

Andy (who is not an AC motor expert)

On Sat, 6 Jun 2020 13:40:55 +0100, Andrew
wrote:

On 06/06/2020 09:58, Cynic wrote:
The mains voltage here has been pretty variable of late. Over the last few days, following some switching round a network fault I've had varying readings from 259 to 240. Anything over 253 is deemed dangerous by northern power grid so they turned out to measure for themselves then switched network connections around that evening. I phoned the following day at midday when the voltage got up to 257 and further switching took place which took daytime volts down to 248. Not had much sun since but NPG engineers reckon my village has a lot of solar generation.


On reading this, I fished out my old Tchaibo plug-in "wattmeter"
and it showed 214 V.

Hmm. Multimeter said 240V, and after being plugged in for an hour
the Wattmeter shows 228 volts. Clearly something inside it is
drifting or changing value. Time to bin it I guess.

Does anyone else use these things ?. It was cheap anyway. Are
there more reliable (expensive) models ?.

How do you know the multimeter is not faulty?

On 06/06/2020 12:01, Scott wrote:
On Fri, 5 Jun 2020 09:15:48 -0700 (PDT), George Miles
wrote:

my friend geoff asks:
Does anybody have a view on domestic voltage stabilisers. From an engineers perspective, I cant see why they would reduce your power consumption:
1) Anything with thermostat control (eg cooker) - no effect.
2) Nearly all electronic stuff has AC to DC inverter these days - no effect
3) Motors, maybe. But this is basically your fridge and these too, being thermostatically controlled use nearly the same power, whatever the voltage.
4) Central heating pump probably would use less.

BUT if the stabiliser has losses (it will have losses) these are 24/7.

So I would expect stabilisers to be at best useless and possibly cause you to use more power than without it.

Any opinions?

The management decided to fit one at my last office. I pointed out
that the electricity consumption comprised computer equipment (with
power supply units), fluorescent then LED lighting, two kettles and
two fridges. I pointed out to our office manager that I did not think
we would save any electricity. She thought I was probably right but
the decision had been made at a more senior level. I think it got
removed in the end but 'the management' is exercising its right of
silence on the subject.


I have fitted two. But only after the customer would not listen to me
and demanded I fit one.

--
Adam

On 06/06/2020 18:49, Scott wrote:
On Sat, 6 Jun 2020 13:40:55 +0100, Andrew
wrote:

On 06/06/2020 09:58, Cynic wrote:
The mains voltage here has been pretty variable of late. Over the last few days, following some switching round a network fault I've had varying readings from 259 to 240. Anything over 253 is deemed dangerous by northern power grid so they turned out to measure for themselves then switched network connections around that evening. I phoned the following day at midday when the voltage got up to 257 and further switching took place which took daytime volts down to 248. Not had much sun since but NPG engineers reckon my village has a lot of solar generation.


On reading this, I fished out my old Tchaibo plug-in "wattmeter"
and it showed 214 V.

Hmm. Multimeter said 240V, and after being plugged in for an hour
the Wattmeter shows 228 volts. Clearly something inside it is
drifting or changing value. Time to bin it I guess.

Does anyone else use these things ?. It was cheap anyway. Are
there more reliable (expensive) models ?.

How do you know the multimeter is not faulty?


I don't. I bought it in 2007 at Maplin (UNI-T UT58).
www.uni-trend.com Hong Kong.

Cost £31. PP9 battery replaced in 2017.

How does one test these things, without access to
a known accurate one ?.

On 06/06/2020 18:04:35, Vir Campestris wrote:
On 06/06/2020 17:08, Fredxx wrote:
Where the speed will be a strong function of mains frequency and only
weakly dependent on precise mains voltage.

An induction motor is one of the devices where a voltage stabiliser
might reduce power consumption slightly.

You sure about that?

It's spinning at the same speed, driving the same load, so the output
power will be the same.

Correct.

Won't it just lag the phase slightly less if the voltage is higher, and
draw slightly less current?

Andy (who is not an AC motor expert)

The efficiency of small motors is pretty poor, and so the magnetic and
copper losses will be proportionate to supply voltage.

There are some inverter driven motors which I would expect to consume
the same power independent of supply voltage. Inverter/smart fridge
compressors are now becoming common.

I have a vague recollection of carrying out an experiment in my electrical machines course of applying varying frequency and reducing the voltage while measuring the current.

With induction motors the ratio v/f should be constant over a range of speeds when controlling output speed if I recall correctly from my electrical machines course some 50 years ago. To all intents and purposes UK mains frequency is constant so reduction or increase of voltage will affect output

On 08/06/2020 17:04:46, Cynic wrote:
With induction motors the ratio v/f should be constant over a range
of speeds when controlling output speed if I recall correctly from my
electrical machines course some 50 years ago. To all intents and
purposes UK mains frequency is constant so reduction or increase of
voltage will affect output

My machines course was more recent :-)

Slip should be relatively small for an induction motor. Let us assume it
might be 10% [1].

Slip is inversely proportional to voltage so a 10% drop in voltage would
now mean rotation is now 89% of mains frequency (11% slip).

Iron losses are a very strong function of voltage, especially if the
motor is designed for reduced cost.

I would expect iron losses to reduce more than the 1% loss in efficiency
due to increased slip. BICBW

[1] A guesstimate!