Saving Electricity - Sparkies please help

[pietpetoors]

To all the sparkies, electrical engineers and other clever people out there.

I received a pamphlet today about a device called an ElectricBuddy

They claim that you just plug it into any wall socket and it will then stabilize the electricity in your house which will then save you up to 50% on your electricity bill.

The big question is, do you guys think this is possible, does it make sense?

They say inter alia

The Electric Buddy stabilizes the voltages and also reduces currents when appliances are switched on. The Electric Buddy prevents the appliances from generating additional heat - which is a result of excess energy. That excess energy is wasted as it doesn't help to improve performance. You however, still pay for that energy even if wasted. By stabilizing the voltage and currents the Power Buddy will ensure that no energy is wasted and thus optimizes the energy usage of all electrical equipment in your house.

Their web site is http://www.electricbuddy.co.za/" onclick="window.open(this.href);return false;

[Mud Dog]

Sounds a little far-fetched to me .... a gimmick, maybe?
I'm not a sparky, but my common sense tells me that any voltage regulating device would have to be fitted to the incoming mains ... not at the end of a leg.

[Jaco Versfeld]

Sounds too-good-to-be-true, and therefore most probably is.

You cannot stabilize the electricity in your house. It sounds more like they are doing something illegal by confusing your power meter (sending jamming signals...)

Just spoke to a colleague of mine doing his Ph.D on high voltage, who also says it is suspicious.

The website doesn't tell you the principle on which the device operates. The statement " ... more efficient if you choose a location where there are fewer appliances nearby and closest to the meter" sounds very suspicious.

They are definitely not doing power correction. The device can also not filter out harmonics on the power line.

To all the sparkies, electrical engineers and other clever people out there.

I received a pamphlet today about a device called an ElectricBuddy

They claim that you just plug it into any wall socket and it will then stabilize the electricity in your house which will then save you up to 50% on your electricity bill.

The big question is, do you guys think this is possible, does it make sense?

They say inter alia

The Electric Buddy stabilizes the voltages and also reduces currents when appliances are switched on. The Electric Buddy prevents the appliances from generating additional heat - which is a result of excess energy. That excess energy is wasted as it doesn't help to improve performance. You however, still pay for that energy even if wasted. By stabilizing the voltage and currents the Power Buddy will ensure that no energy is wasted and thus optimizes the energy usage of all electrical equipment in your house.

Their web site is http://www.electricbuddy.co.za/" onclick="window.open(this.href);return false;

[Mr_B]

Note that none of the testimonies are given by a contactable references, and one of the references, Noel Hunter, sounds like a reseller... so why no contact details? And under contact details, no physical address, just a PO Box... looks fishy ...sounds fishy... it can probably cure HIV as well!

[Mr_B]

Interestingly... here is another one of these devices:

http://www.walcopower.co.za/products/power-buddy" onclick="window.open(this.href);return false;

[Mr_B]

This device seems to have a lot in common with the famous gangle pin!

[Piesang]

the amazing geyser blanket

die blanket waarvan hul praat is ook 'n slenter. Ek het nou al vier keer dit gehad dat die geyser bokand die band oop-en-bloot sit (tans twee in die huis waar ek nou is) nog nooit het ek met die hand kon voel dat die buite dop van die geyser warm is nie. En as die hutte nie van binne af buite toe slaan nie sal die koue ook nie van buite af binne toe slaan nie.

Iemand het lekker geld gemaak by die munisipaliteite wat dit aangekoop het om verniet in huise te instaleer.

[Jaco Versfeld]

This makes more sense. I will find out about power factor correction for single phase networks (i.e., normal 220v).

When you have an inductive load, there is a phase difference between the voltage (V) wave and the current (I) wave. Power is calculated as V*I. Due to the phase offset, you cannot obtain maximum energy transfer.

For big plants using three-phase power grids, it is a known solution to do power factor correction.

I think this might actually work. I will find out from my colleagues if there is a real benefit for power factor correction on single phase networks.

More on power factor correction: http://en.wikipedia.org/wiki/Power_factor" onclick="window.open(this.href);return false;

Interestingly... here is another one of these devices:

http://www.walcopower.co.za/products/power-buddy" onclick="window.open(this.href);return false;

[Jaco Versfeld]

I am not too sure about this one. The general opinion is that these blankets do work. I will find out from our energy specialists about these blankets, but as far as I know, they do make a difference.

Also, ripple control on your geyser is supposed to lower your bill. I was seriously cheesed off the other day, when, for the second time this year, my geyser was cold. First time I thought the geyser's element has blown, but the geyser is only 1.5 years old. Second time I found the culprit. Ripple control was switched off. I phoned Joburg City and threatened to remove the unit. The response was that I can do it, but I will pay more (extra levy, or something). Any case, geyser was warm the afternoon.

the amazing geyser blanket

die blanket waarvan hul praat is ook 'n slenter. Ek het nou al vier keer dit gehad dat die geyser bokand die band oop-en-bloot sit (tans twee in die huis waar ek nou is) nog nooit het ek met die hand kon voel dat die buite dop van die geyser warm is nie. En as die hutte nie van binne af buite toe slaan nie sal die koue ook nie van buite af binne toe slaan nie.

Iemand het lekker geld gemaak by die munisipaliteite wat dit aangekoop het om verniet in huise te instaleer.

[pietpetoors]

What is ripple control?

[Jaco Versfeld]

Ripple control is where the municipality will switch off your geyser for a (hopefully) short period during peak load. SA's electricity load has two major peaks, around 8:00 and I think around 17:00 (if memory serves me correctly). In order to reduce the electricity load during these peaks, the municipality will then switch off geysers (normally done remotely).

Our unit is a big ugly unit sitting next to the distribution board.

It will have no significant effect on the water temperature, unless the communication circuit is faulty.

What is ripple control?

[Mud Dog]

The ripple relay is a remotely controlled switch ... used as said by municipalities to remotely switch off your geyser. The way it works is that it is programmed to recognise a certain pattern of 'ripples' in the power supply ... much like morse code. Your suburb / area is allocated a pair of on/off codes and the relay responds accordingly. During peak consumption periods load shedding is practised by turning off a couple of alternating suburbs for a few hours at a time.

I don't think that this actually saves you much IRO consumption, because if there has been heat loss / hot water usage, the geyser still has to bring it back up to temp again once it is switched back on. In the same scenario without the ripple relay the geyser would merely maintain the temp and the thermostat would switch it on and off as required.

[Clarence]

Power factor correction only works on 3 phase. If my memory is correct you need a lag of .9 to operate at its best.

[Family_Dog]

My feeling is that that buddy is as useful as a magnet wrapped around a fuel line on an engine... ;)


-F_D

[pietpetoors]

This is quite interesting, I also think its a gadget. Perhaps I can persuade to give me a loan unit so I can evaluate it. If it works they will get one hell of an exposure, if it don't, tough luck to them.

By the way, about the geyser.
My geyser is outside, I have painted it black. I also installed a timer. We are home all day and I found that woman always use the hot water tap even if it is only to fill the cettle. So they take out water from the geyser, only cold water enters the cettle but the geyser have to re-heat the water the replaced it. So I installed the timer so the geyser is switched off all day. It goes on in the morning at 05h30 so we can have hot water when we get up at 06h30. It switches off at 08h30 so that it had time to heat the water for the day. It then only comes on again tonight at 20h00 and goes off again at 22h00. We always have hot water even if you wanna take a shower at 17h00. I think the black geyser helps keeping the water hot during summer.
We are 3 in the house and we use on average R350 electricity per month and that is with 3 computers running all day.

I know there are lots of debates about putting a timer on the geyser, but I really think it works, same for the black geyser.

[Mud Dog]

What also helps a lot is insulating the hot water pipes (after the geyser), especially when small amounts of hot water are required ... often as much hot water is needed to heat the pipes before it comes out hot than what's needed for the actual task, and if it's a cold day there is a fair amount of heat loss. More so if the tap is far from the geyser. Additionally there can be a fair amount of heat loss from the geyser through the first metre or so of pipe even though there is not hot water being used.

[ChrisF]

Pieter as jy regtig geld wil spaar - MOENIE die gemors koop nie.

Daar is drie maniere om krag te spaar:
1) gebruik minder krag - skakel items af of gebruik energie doeltreefende ligte of solar verwarming ens .....

2) Verminder die "maksimum aanvraag" - SLEGS vir industriele kliente van toepassing, spesifiek die wat krag betaal volgens die "two part tariff" stelsel (eenhede gebruik en maksimum aanvraag)

3) Arbeidsfaktor - kort beskrywing, induktiewe toerusting veroorsaak n "arbeidsfaktor hoek", die hoek verlaag die effektiwieteit van n aantal elektriese toerusting. Gevolglik word meer elektrisiteit benodig vir dieselfde take, tot 50% meer !! Die arbeids faktor kan weer verbeter word deur die gebruik van kapasitors - goedkoop manier om BAIE energie te spaar. MAAR, dit is weereens gemik op industriele persele. Teoreties kan dit van waarde wees vir huise, my raaiskoot is dat dit slegs n paar pesent besparing te weeg sal bring, indien enige iets.


As jy wil krag spaar kyk na waar jy dit gebruik en oorweeg meer effektiewe opsies:
- swembad pomp, moontlik korter tye laat loop
- geyser, moontlik solar en/of timer en/of geyser isolasie en/of isoleer warm water pype (elk van die het navolgers)
- ligte, gebruik energie doeltreffende ligte WAAR TOEPASLIK (die ligte werk nie orals ewe goed nie)
- verhitting/verkoeling, isoleer die plafon so goed as moontlik

[Bandit]

Hey guys, my two cents worth...
Power correction or load balancing can only really be used effectively on 3 phase applications, either light, heavy or HV industrial.
Any sort of load balancing, current rectification would have to be installed on your main incoming supply and NOT just plugged in randomly in a socket outlet.
The usage of capacitors is an effective way of stabilising your voltage, whether the incoming supply is either high or low, your outgoing supply will remain at a constant voltage, as per the rating of your cap.
The current situation in SA is that the grid has not been upgraded in many years as it sound have been, so there is now a crisis, as the demand for power is higher than what can actually be generated, so the grid has in a way, destabilised. This results in the spikes and dips that keep blowing electrical appliances.
The only way in which to save electricity is to watch the way we use it. If something is not to be used, then turn it off and unplug it. Many times people will just turn an appliance off, but it keep drawing power, so turn it off at the socket outlet, or just unplug it completely.
You main power consuming devices in a house are: stoves, heater, tumble driers, geyser and pool pumps. Your lights and plugs in a normal household should not draw that much power on your general house hold appliances.
Save where you can, but there will be many sharks swimming in a sea of uncertainty trying to sell products that do not work.

[Striker]

Die gedoente het my ook nou 'n idee gegee! Ek gaan 'n wireless extension bou, jy plug die sender by 'n muurprop in en dan kan jy die ander muurprop in 'n radius van 100m om jou huis gebruik - die krag word dan deur telematics gestuur van die sender af na die reciever, dit sal ook dan die harmonics uitskakel. Stel iemand dalk belang? Sal dit verkoop vir so R 500.00 stuk.










As iemand met daardie patent kan geld maak hoekom nie ek ook nie?

[Clarence]

Make sure you use the right caps as i have seen many in the old day that have blown up becasue they cannot take the heat in this country. Yes it might seem strange but where i work before we had four sets of 9 banks of power factor correction. They blew after a couple of years and the outcome was that the cap did not suit our country. My understanding of power factort correction is better suited for running machinary

[Piesang]

Die gedoente het my ook nou 'n idee gegee! Ek gaan 'n wireless extension bou, jy plug die sender by 'n muurprop in en dan kan jy die ander muurprop in 'n radius van 100m om jou huis gebruik - die krag word dan deur telematics gestuur van die sender af na die reciever, dit sal ook dan die harmonics uitskakel. Stel iemand dalk belang? Sal dit verkoop vir so R 500.00 stuk.










As iemand met daardie patent kan geld maak hoekom nie ek ook nie?

Striker en dan prop jy hom by jou bruurman in en spaar jou krag

[hentey]

I dont want to sound clever because some brighter spark might prove me wrong,but this is how I see it.Power factor correction units work only on inductive loads (that is 3 phase motors) and not on resistive loads(that is elements like stoves,geysers,kettles etc)Most house holds works on a single phase supply so I cannot see how the normal house hold will benefit with the PFC units if it exists(that is single phase PFC units).Switching your geyser off at certain times for periods can save you KWH's but this is no easy calculation.The capacity of the HWC,the size of the element,and also the need for hot water at specific times are all factors that will have an impact on this calculation.So if you want to save on electricity................shower or bath less than you used to,braai more,and dont drink coffee or tea.Bottom line is .......if it uses electricity and it generates heat.........it also eats your money.

[cprinsloo]

Hi,

Power factor correction can be used in single phase as well. Very little benefit in a household, because it is only inductive or capasitive loads that will cause a lagging or leading load (power) factor , not pure resistive loads (elements, globes etc). Inductive loads are motors, either single phase or 3 phase. Because motors are used extensively in industry which cause the lagging power factor, this is off-set by capasitor banks, to get the power factor as close to 1 as possible. Synchronous generators can also be used for this function.

The gadget they showed is only that, a gadget.

Cheers,

C

[Clarence]

True but now we got a company that has say 75 3 phase battery chargers on a 12 hr cycle will a power factor correction help????????????????

[Mud Dog]

Die gedoente het my ook nou 'n idee gegee! Ek gaan 'n wireless extension bou, jy plug die sender by 'n muurprop in en dan kan jy die ander muurprop in 'n radius van 100m om jou huis gebruik - die krag word dan deur telematics gestuur van die sender af na die reciever, dit sal ook dan die harmonics uitskakel. Stel iemand dalk belang? Sal dit verkoop vir so R 500.00 stuk.










As iemand met daardie patent kan geld maak hoekom nie ek ook nie?

Why not, .... cheap at the price .... and I would be your first customer so that I could send a bolt of 220v over the wall into my neighbour's dog's behind when it starts with it's incessant barking at nothing in particular at all hours!

[Bandit]

Offtopic

Hey Andy, try the following:
Get a decent size piece of thin metal plate, attach 4 large blocks of rubber, one to each corner of the plate. Attach a neutral (black) wire to the plate. In the centre of the plate, place a plastic dog feeding bowl, drill a hole through the side of the bowl, about 50mm up from the bottom, place a bolt and nut through the hole and attach your live (red) wire to the bolt. Attach the red and black wires to a 50000 volt step up transformer, like they use for electric fences. Fill the bowl with a wet type of dog food (must cover the bolt) and place the entire contraption over your neighbours wall. Just plug it into a 220 volt supply and your problems should be solved! Works wonders on cats, so don't see why it shouldn't work on dogs...

[Mud Dog]

Offtopic

Darryl, you need help, China! ..... and I thought I had a sick sense of humour!!

[hentey]

Offtopic

Hey Andy, try the following:
Get a decent size piece of thin metal plate, attach 4 large blocks of rubber, one to each corner of the plate. Attach a neutral (black) wire to the plate. In the centre of the plate, place a plastic dog feeding bowl, drill a hole through the side of the bowl, about 50mm up from the bottom, place a bolt and nut through the hole and attach your live (red) wire to the bolt. Attach the red and black wires to a 50000 volt step up transformer, like they use for electric fences. Fill the bowl with a wet type of dog food (must cover the bolt) and place the entire contraption over your neighbours wall. Just plug it into a 220 volt supply and your problems should be solved! Works wonders on cats, so don't see why it shouldn't work on dogs...

OFF TOPIC But if the SPCA reads this.......huge problems!!!!!!!!

[pietpetoors]

Offtopic

Andy I know this is off topic as well but, the best thing for a barking dog is you have to: Spuit hom nat!. The best is if he does not see you or do not know where the water is coming from. It don't have to be very wet, even one of those big water guns will work. I have healed many neighbors' dogs from their barking sickness that way. Where possible I sommer take the hose pipe and just give to one quick spray and then it shuts up.

[Mud Dog]

Offtopic

Andy I know this is off topic as well but, the best thing for a barking dog is you have to: Spuit hom nat!. The best is if he does not see you or do not know where the water is coming from. It don't have to be very wet, even one of those big water guns will work. I have healed many neighbors' dogs from their barking sickness that way. Where possible I sommer take the hose pipe and just give to one quick spray and then it shuts up.

Offtopic

Thanks for the tip Pieter .... if it works, at least it will be one idea on this thread that is actually worth trying!

[Spartan]

The gadget they showed is only that, a gadget.

Dit is presies wat Chris se n gadget, die ouens wat die ding verkoop is besig met iets om geld te wil maak uit ander se onkunde van krag.

[Piesang]

Praat van onkunde oor krag

Ek het nou die dag 'n rots opgetel en vergeet ek het nie meer die krag van 20 jaar terug nie

Ek het altyd gegloo dat 'n motor wat hardloop nie veel krag trek nie, maar die meeste gebruik om in werking te kom, soos met 'n elektriese grassnyer wat gereeld aan en af gesit word, teen oor 'n water pomp wat heeldag hardloop.

[Mud Dog]

Alles verloor bietjie krag as dit ouer raak, Pieter!

An electric motor always draws more on start-up than when it's running, but don't be fooled, pool pumps and lawnmowers draw a fair amount of juice, particularly since they are under load while running.

[ChrisF]

Pieter n moter se "aansit stroom" is tot 6 keer meer as die "loop stroom".

MAAR dit is slegs vir 3 tot 10 sekondes.

SLEG n probleem vir n gras snyer wat elke 20 sekondes afgesit word en dan aangesit word. Maar maak GEEN verskil vir iets soos n swembad pomp nie, dan is dit slegs die tyd wat dit loop wat bepaal hoeveel krag dit gebruik.

[pietpetoors]

This is a "hear say" story so I wonder if some of our local electricians can confirm this:
An electrician told my brother in law that if something goes wrong with the ballast inside a fluorescent light, that the light will then use far more electricity than it should. He said that apparently the Fluorescent light can work without the ballast. He also said that most fluorescent lights' ballast only last about a year of normal functioning and then after that it starts to use more electricity. The danger here is that you think that you use a fluorescent light to save energy but in the end you do not really save because of a faulty ballast

Does anybody know if this is true?

[OOOOMS]

This is a "hear say" story so I wonder if some of our local electricians can confirm this:
An electrician told my brother in law that if something goes wrong with the ballast inside a fluorescent light, that the light will then use far more electricity than it should. He said that apparently the Fluorescent light can work without the ballast. He also said that most fluorescent lights' ballast only last about a year of normal functioning and then after that it starts to use more electricity. The danger here is that you think that you use a fluorescent light to save energy but in the end you do not really save because of a default ballast

Does anybody know if this is true?

To my knowledge a fluorescent tube will not function without a ballast / choke (the tube requires the initial 'boost' to get the Mercury to activate). Without that it will not light up.
The more modern fittings use electronic ballasts which use less power on start-up, and are referred to as energy saving lately or green ballasts.

If they use more power after a year or so as mentioned, could very well be true, but I assume he is referring to the older tipe ballasts.

[Thabogrobler]

green ballasts.

Dankie tog ek het verkeerd gelees!

[Mud Dog]

Also doubt that there is any real truth in that Pieter. A fluorescent tube won't work without a suitable ballast IMO. I cannot comment on the efficiency of the older transformer type ballasts and the newer electronic ones, but the electronic ones are more likely to give trouble or fail, thus necessitating their replacement ... an additional cost that may negate any power saving in it's lifespan.

[Donkey]

This is a "hear say" story so I wonder if some of our local electricians can confirm this:
An electrician told my brother in law that if something goes wrong with the ballast inside a fluorescent light, that the light will then use far more electricity than it should. He said that apparently the Fluorescent light can work without the ballast. He also said that most fluorescent lights' ballast only last about a year of normal functioning and then after that it starts to use more electricity. The danger here is that you think that you use a fluorescent light to save energy but in the end you do not really save because of a default ballast

Does anybody know if this is true?

It's amazing and disgusting what some people will say just to convince the lay person, as Mark says a flourescent tube will not work without the ballast, and as far as I know a ballast can last for a very long time - the fitting in our garage is going to 10 years, still works.

Our monthly bill comes to about R350 - R400 (ESKOM supply), sometimes even R450 depending how much baking was done.

But as said also try and save where you can, energy saving lights, geyser blanket and insulate water pipes, boil one and a half cup of water if making a cup of coffee instead of boiling 1.5 ltr of water. In winter dress warmly instead of using heaters - you'll be surprised how my people are obsessed with heaters

A friend of CupCakes mother calls me this past winter complaing that the mains keeps on tripping. So off I went and discovered that at any given point, they run 4 heaters in the house they wanted me to "upgrade" the supply, which I refused to do for their own safety. Upgrading would have meant a bigger circuit breaker as per his suggestion. The breaker is there to protect the wire (insulation) and so advised them to either dress warm or consider something else. They were not impressed with me Poor electrical insulation is one of the causes of fires in our homes.

[cruiserhj60]

Hi all,
Here are some answers for you.
1. ElectricBuddy. This is a con. Stay away. Paying lots of money for no benifit.
2. Ripple Control. As said before this is a function whereby the council controls your Geyser via a signal sent via your power cables.
The older systems used a special ripple generator which generated signals at 1050 HZ. This is now done electronically.
The council does this to control their overall maximum demand charge measured by ESKOM. Thus keeping there bill down. There are
also generally penalties for exceeding certain levels. The council controls all of this by switching geysers (a high load) on and off in
various areas of the town at different times.
3. Power factor correction. This is generally the installation of capacitors into the system to counteract the inductive load. Typically
motors. The power factor correction will lower the Kilo Volt Amps (KVA). Effectively what it does is bring the KVA value more in line
with the KW value. This will not do anything for your household bill as you pay for Kilowatts (KW). Industrial installations also pay
what is called a maximum demand charge. This is the KVA. Thus by reducing the KVA you reduce your bill.
There is a bit more to the whole picture, but this is the basics.
Hope this answers a few questions.
Regards
Trevor

[ChrisF]

True but now we got a company that has say 75 3 phase battery chargers on a 12 hr cycle will a power factor correction help????????????????

Clarence the proper agents for Power Factor Correction will come out to your site and evaluate your "situation". They will then record your current setup and present a plan of action.

For the large users they then often propose a solution whereby they install power factor correction FREE of CHARGE - BUT, at a percentage of the savings ... clearly they need to do their homework properly to ensure that the deal works for all involved.

so YES, for large users power factor correction DO save energy and $$.

[pietpetoors]

Thanx for all the advice.
I actually hoped the story was true because that would have been the perfect sales pitch for selling LED replacement tubes.

If I switch on all the lights in my house I now use the big total of 120 watts

[pietpetoors]

I have another question

With the current LED Tubes you have to connect the 220V directly to the tube, ie bypass the ballast and starter.

They now manufacture Ballast Compatible LED Tubes which will save on time since you don't have to change all the wiring, BUT my big question now is, what in a Fluorescent light uses the most electricity, the tube or the Ballast? I am no electrician but it feels to me that having a Ballast Compatible LED Tube will defeat the object. My opinion is that a LED tube connected directly to 220V will use less energy than one which still uses the ballast

[Donkey]

I suspect an LED setup would use less current in comparison to a normal ballast operated setup. Where you use the most currnet in a normal setup is when you first switch the light on, the surge if I may call it is to excite to mercury to come on, which is what makes up the light. But I expect that difference to be so minimal that I wouldn't worry about.

One would have to run a test perhaps on both and see, just my 2cw

[Stef]

LED will be consuming less than ballast, but one could argue that fluoro's are saving electricity because it has a leading power factor, also the reason it can not be dimmed through normal phase control. So install more fluoro's

As mentioned above, the power factor is the difference between the actual power (kW) & phantom power (kVA; what the metro skelms bill you on). Inductive load yields a lagging power factor & capacitive loads will yield a leading power factor; hence the reason for capacitor banks to get the factor closer to 1. The power factor is actually Cosɸ , thus a power factor of 0.8 is an angle of 36° lagging or leading, depending on the load, but mostly it will be lagging. The closer the factor is to 1 the smaller the angle; thus more efficient.
For example a 100w output at PF of 0.8 one would need 100/80 = 125 W (V*I or VA) input; so the formula for real power is P = VI Cosɸ

The above is due to (if memory serves) the inductive/capactive reactance XL = 2πfL & XC = 1/2πfC & then the total impedance Z = SQRT(R^2 + (XL - XC)^2)

Clear as mud?

[pietpetoors]

Thanx Stef, that makes 100% sense, so that is why if I measure a LED downlight which has 3x 1watt LEDs in, it actually uses 4.2 watt and not 3.

[Stef]

Thanx Stef, that makes 100% sense, so that is why if I measure a LED downlight which has 3x 1watt LEDs in, it actually uses 4.2 watt and not 3.

Same concept, but this is purely the effiency of the LED's themselves (if you used DC to power them). The formulae above is for AC, hence the f for freqeuncy.
The data sheets of the LED's should gice you an effiency rating; it seems then the LED's are rated at output power.

[ChrisF]

Piet on one of the sites where we work the sparky has installed LED "tubes" - at about R600 a unit !! (thats for the tube, unit/bracket, transformer etc)


man moet bietjie BAIE krag spaar om dit af te betaal !!

[Stef]

'n gewone 5' dubbel fluoro is al R320+ hier, dis sonder die buise...so R600 is seker nie so sleg nie

[Family_Dog]

For example a 100w output at PF of 0.8 one would need 100/80 = 125 W (V*I or VA) input; so the formula for real power is P = VI Cosɸ

The above is due to (if memory serves) the inductive/capactive reactance XL = 2πfL & XC = 1/2πfC & then the total impedance Z = SQRT(R^2 + (XL - XC)^2)

Stef, as this is a family forum, please refrain from using such harsh language!!




-F_D

[Stef]

For example a 100w output at PF of 0.8 one would need 100/80 = 125 W (V*I or VA) input; so the formula for real power is P = VI Cosɸ

The above is due to (if memory serves) the inductive/capactive reactance XL = 2πfL & XC = 1/2πfC & then the total impedance Z = SQRT(R^2 + (XL - XC)^2)

Stef, as this is a family forum, please refrain from using such harsh language!!




-F_D

Now you must realise how harsh that was on the grey matter...