/ A device that reduces electrical surges and saves 20%???
I live in Fort William - if that makes any odds.
I am no sparky but if "surges" comprise 20% of your electricity useage then I imagine that there is something very wrong with your supply. My money is on "scam"
I'll try not to get to mathematical but your meter can only read power consumption as volts x current. If you have a certain type of load it can affect the way the current is affected by the voltage. In a normal resistive load the current is at a peak when the voltage is at a peak. Most houses are like this. In an industrial situation you can have a lot of motors that affect the current and hold it back due to the way current works in a coil. This means that the power you read on your meter will be different to what you are actually using. This can be fixed by fitting capacitors to your supply. It's called power factor correction.
You could also be getting transient spikes if you live near an industrial area where plant is switched on an off and this is injected into the mains. They're very short but big. I would be surprised if your meter catches them but your household appliances, computers etc will.
Need more info about what it is and what it does really.
UK voltage is 230V +10% - 6% if you can keep the voltage to the -6% end rather than the +10% end you save as Energy (P)=Voltage(V) X Current(I)
You canít change the current thing consume but you can change the voltage, to an extent.
That doesn't really work as most appliances these days have a control loop that adjust the current drawn to deliver the power needed regardless of voltage - for example fridges, ovens and switch mode power supplies (inside tv's, computers, consoles etc)
If a lot of your usage is on lighting or inductive devices such as motors or transformers (where higher voltages may saturate the ferrous core) you will see a saving, but that would be an atypical household.
Of course you can change the current. Changing the voltage will change the current!
The system exists already in France and many other EU countries for many years.
Basically for a discount you accept that the power company can remotly shut down your heating. Mostly they install this system in houses with electrical storage heating. Only in the UK, part of the US, and third world countries we have such poor electrical standards.
> Of course you can change the current. Changing the voltage will change the current!
I think the power meters actually measure power used, so as far as you are concerned the power factor of the load is irrelevent. For the supply company unbalanced and high power factor loads are a nightmare.
Can't speak for third world countries, but perhaps only in the UK and US has electricity up until now been so cheap?
> ^ this
> V=IR, I=V/R
Or, alternatively, fit lower power lightbulbs! Stuff like fridges will still use the same amount of electricity - even more - because to get the same amount of cooling the compressor has to run longer and probably less efficiently. Similarly cookers and kettles - the amount of energy needed to boil water doesn't change because you are using effectively a lower power kettle.
French (nuclear) electricity is cheaper to produce than ours. Thats why we import some of it.
I would guess it's a surge protector and choking the voltage a bit, but whether you can save that much I do not know.
The current changes because you've changed the voltage FFS!!
If you power a 100W light how do you change the current except by changing the voltage. The resistance stays the same (within normal voltage fluctuations) So tell my how you alter the current?
The box referred to keeps the voltage at the low end of what normal electrical items are guaranteed to run.
@WIntree Most items!?!?! some items have a loop on the output to the appliance, most don't and the current delivered remains the same.
If the current remained the same and you lower the voltage you have also lowered the power consumed.
> The current changes because you've changed the voltage FFS!!
I was agreeing with you ya tube. That's why I pointed to your post and said "^ this"
The losses in a cheap power supply may vary with supply voltage but that should be marginal. If it wasn't marginal the power supply would risk overheating at some supply voltages.
On non-electronic resistive loads like incandescent bulbs & heating any reduced power will mean less light and less heat.
Reactive loads like motors for fridge/freezer/central heating/air-con may consume less power but they'll produce less output so it' difficult to say if they'll be more or less efficient.
Overall if somebody is selling a clever box that sounds strange and they won't tell you the price then it is a scam.
The only thing in my house that doesn't adjust it's current draw to counteract a lower voltage are the lights.
Fridge - Oven - Kettle - these are the if power users and all adjust.
Hair dryer - guess what? You use it longer
Tumble dryer - you either run if longer or have clothes less dried
TV - Desktop computer - laptop charger - phone charger - electronic photo frame - miniature dyson charger - and many more. All off these are switch mode power supplies which by the very means they operate adjust their current draw to deliver the required power.
Microwave - you could argue the toss on this one
Dyson - I don't know if Mr Dyson's clever digital motors adjust.
So I stand by what I said. We use power to get things done. Reduce the supply level and we use it for longer.
Now cheap induction motors may be less wasteful @220V than 240V so you cold win there by lowering the voltage, but induction motors typically represent a small fraction of domestic use in the UK. Different if you have air conditioning.
Get yourself signed up to the TPS.
> The current changes because you've changed the voltage FFS!!
> If you power a 100W light how do you change the current except by changing the voltage. The resistance stays the same (within normal voltage fluctuations) So tell my how you alter the current?
> The box referred to keeps the voltage at the low end of what normal electrical items are guaranteed to run.
> @WIntree Most items!?!?! some items have a loop on the output to the appliance, most don't and the current delivered remains the same.
> If the current remained the same and you lower the voltage you have also lowered the power consumed.
As I say I didn't want to get into the heavy maths and physics but
It's a scam. I've heard of it before.
It's a worthless device that effectively drops the mains voltage a bit. If you are running loads of incandescent lamps it might save you a little, at the cost of dimmer bulbs, but stuff like fridges and heaters are on a thermostat. If they run at lower power then they need to run for longer.
The fact that they cold called should ring alarm bells. No reputable company cold calls.
Just think about it... If the device actually worked, every business with a significant electricity bill would fit one.
> I think the power meters actually measure power used, so as far as you are concerned the power factor of the load is irrelevent. For the supply company unbalanced and high power factor loads are a nightmare.
Yes, that's what I thought. I'm not sure how you can reduce the voltage though, other than putting in a transformer. Putting the whole house on a transformer sounds pretty dodgy, Where will you put a 14KVA transformer?
> Just think about it... If the device actually worked, every business with a significant electricity bill would fit one.
Many do! Voltage Optimisation has been around a fair while in industry, is a proven technology and can be extremely effective. The recent trend towards domestic units is a constant source of discussion/argument amongst electricians and engineers. Some swear by its effectiveness and others think it nothing more than a scam. To satisfy myself, I fitted a unit in my own home about 18 months ago (I was approached by one manufacturer to supply/install them). My consumption appears to have reduced by around 7-8%. The 20% figures usually bandied about are over-ambitious and rarely, if ever, achievable in a domestic situation. The units work most effectively (but not exclusively) on resistive loads that do not work on a thermostat, therefore lighting and basic electric showers are the prime candidates. Lighting does dim slightly when the unit kicks in, but it is barely perceptible. Certainly not enough to worry about.
Would I have one of these units fitted if I was paying for it with my own money? Nope. Too expensive for too small a saving. Fit low energy or LED lamps instead and turn them off when you ain't using them. Voltage Optimisation certainly works - there's no black magic involved, but not enough in a domestic situation to make it worthwhile IMO. And any company cold calling to sell it you is unlikely to offer it at a good price.
20% is approx the amount of overcapacity in our whole system to accommodate for power outages on stations, and of course the intermittency of renewables, it would be a no brainier to change the building codes for new installations to ensure that new homes would have them I would have thought. I don't believe they have.
You do know that P is for power not energy?
> The only thing in my house that doesn't adjust it's current draw to counteract a lower voltage are the lights.
All wrong do you really know anything about electrical engineering?
Power factor too is a major waste of energy, that's why industial units are made with huge banks of capacitors in them to get as close to a power factor of 1 as is possible.
Powere factor is the relationship of the voltage sin wave to the current sin wave.
> You do know that P is for power not energy?
Energy is Power over time so both useful you pay your bills on energy kWh and the power consumed (instantaneous) is in (W)atts
No they aren't worth it in the home.
Thanks for all the useful advice. I won't be going any further with this.
Its good to have UKC where you can air & discuss even stuff like this.
Poor power factor in itself doesn't waste energy - it buggers up the distribution, though, which is why there is legislation over low power factor loads.
> Poor power factor in itself doesn't waste energy - it buggers up the distribution, though, which is why there is legislation over low power factor loads.
It most certainly does waste energy and as a consumer you end up paying for more energy.
For example, if the load power factor were as low as 0.7, the apparent power would be 1.4 times the real power used by the load. This 1.4 times is what goes through you meter.
The meter responds to instantaneous IV, and therefore only measures actual power dissipated (the component of I and V that are in phase), not average V.A.
As a thought experiment, connect a pure reactive load to the mains. Where exactly is your energy being wasted ? what dissipates it ? a pure inductor or capacitor can't.
PF is a cost on an industrial scale. You get fined heavily for exceeing power factor limits and this is because losses do occur with poor power factor loads - they occur in the distribution network because peak currents have to increase to deliver the same power.
On a household level , I think it gets dealt with these days by putting the onus on the household equipment suppliers to fall within limits and not put the onus on the householder.
In houses there are a mix of inductive and capacitive loads which will hopefully cancel out.
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