[Niteshade]

Ebay # 190257641015

Reactive loads in homes and businesses do waste allot of energy. This box is supposed to make loads look resistive, thus saving money. It appears to have filtering benefits as well as surge protection. I'm not selling this unit nor do I know the person who is- it's an example I stumbled on while looking around.

I believe that this device would be beneficial since most devices in our homes use some kind of transformer, which is a reactive load.

The way to make an inductive load look more resistive is to put a capacitor in parallel with it, so there is a way to do this as an experiment that would be less expensive. I'll look and see where the information is.

[JoshK]

I know nothing about this subject really.  Occam I think knows a bit.  How exactly does one save money though?  I thought PFC was something industrial businesses use to get better rates from the electric company.

[jtwrace]

I use this http://powergy.com/products.aspx and it has PFC.

Worth the money IMO.

[randytsuch]

Here you go
http://en.wikipedia.org/wiki/Power_factor_correction

saves money by increasing efficiency.
If you had a current probe, and a scope, and compared the voltage versus current input for a device, the waveforms ideally look identical.  If this is the case, then PF=1.  The more difference there is between the two, the lower the PF.

Rnady

[satfrat]

Ebay # 190257641015

Reactive loads in homes and businesses do waste allot of energy. This box is supposed to make loads look resistive, thus saving money. It appears to have filtering benefits as well as surge protection. I'm not selling this unit nor do I know the person who is- it's an example I stumbled on while looking around.

I believe that this device would be beneficial since most devices in our homes use some kind of transformer, which is a reactive load.

The way to make an inductive load look more resistive is to put a capacitor in parallel with it, so there is a way to do this as an experiment that would be less expensive. I'll look and see where the information is.

FWIW, unless this can be proven to be a legitimate company, you just lost credibilty in my eyes Blair.

Cheers,
Robin

[KS]

First, most home electric bills, at least mine, are billed for kilowatt hours used.  This is a measure of the electricity I used, not what the power company supplied, including that wasted by reactive losses.  If I was billed in kva-hours, I'd consider power factor correction.  Kilo volt amp hours are volts x amps* x hours which include the reactive losses.  Kilowatts are volts x amps* x power factor** x hours.  Kilowatts are always less the kva (except at unity power factor).

What causes the reactive losses?  Some of the loads are resistive.  Incandescent light bulbs, toasters, etc. are resistive loads...these have no reactive component so don't change the power factor.  Some loads are inductive.  Just about every electric motor is an induction motor, and the newer high efficiency ones have a run-capacitor to improve their power factor.  Fluorescent light ballasts are inductive.  There might be some capacitive loads, but I can't think of any significant ones.  On our audio gear, the transformers are inductive loads, and the bigger the better and more inductive.

Adding capacitors to the circuit is one way to improve the power factor on inductive loads.  Over-exciting a synchronous motor  works in industrial applications.

I glanced at the info on that eBay item, and it looks good, but what's the point?  As long as my electric bill is measuring kilowatts, I can't reduce the bill by power factor correction.  If I want to clean up the power or get surge protection, it's likely that my money is better spent on a whole-panel surge protector (which I need and have) or on methods to clean the power waveform.

*For single phase.  Multiply by the square root of three for 3-phase power.
**Always less than one...like .8 or .7...except where there are no inductive or capacitive loads, or where their reactive load is exactly balanced.

[JoshK]

That is why I was asking how it saved us money.  Your explaination was succinct.

[xsb7244]

How effective is the Furman power factor pro or the Furman elite 15 PF i ?

[Occam]

Power factor correction is a problematic issue. Indeed, industrial/commercial customers of the electrical grid are often have a surcharge to the extent that their Kva exceeds the Kw consumption. Although the reactive component is imaginary (in a mathematical sense) it does consume energy to the extent it encounters (primarily) ESR (equivalent series resistance) in the transmission line, transformers, etc... in both the delivery infrastructure as well as our own uses. But these power factor charges, at present, are only charged to industrial/commercial consumers, typically those who have 3 phase service.

What these conditioners, whatever.... who advertise power factor correction are providing is simply a capacitance across the line(s), usually in the form of protected motor run capacitors. The extent to which whatever subjective improvements is provided by correction rather that a capacitors ability to shunt noise is debateable, and to my knowledge, no one has demonstated squat. But it is convenient for anyone who is selling conditioners/surge protectors to add 'power factor correction' to their marketing blurbs. (I think I'll do that myself)

Indeed, if we have a lot of motors running in our homes, this passive capacitive correction can be effective as shown in one of the referenced urls -
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=190257641015

But that 'NASA'  test was for a large 3 phase industrial motor, and indeed a bunch of caps, sized and configured specifically for a specific motor running at a specific load can be quite effective. But frankly, its not germane to home use, where those caps are going to be 'in circuit' whether those motors are running or not. If those caps are in circuit while that inductive load is not running, its going to swing the pf off of 1 to the extent it previously corrected the inductive load (the motor) towards 1.

And while a PF other than 1 is less than ideal for the grid's infrastructure, who says those typical 'triplet' harmonics make for bad audio? A couple of odd harmonics and you've got PS Audio's Multiwave(tm). There are some valid arguments for squaring the sinus.

FWIW,
Paul

[Niteshade]

"FWIW, unless this can be proven to be a legitimate company, you just lost credibilty in my eyes Blair. "

Robin: That was an example. Maybe the company is or isn't a good one. I NEVER ENDORESED the seller or the product!

Chill out! 

[Niteshade]

Our test setup in lab was 3-phase. I have seen many computer power supplies that say they have built in power factor correction and thought that  it may be of some use with other applications.

[satfrat]

"FWIW, unless this can be proven to be a legitimate company, you just lost credibilty in my eyes Blair. "

Robin: That was an example. Maybe the company is or isn't a good one. I NEVER ENDORESED the seller or the product!

Chill out! 

I'll stand by what I said thank you.

Chill out yourself.

Cheers,
Robin

[Niteshade]

http://energystar.custhelp.com/cgi-bin/energystar.cfg/php/enduser/std_adp.php?p_faqid=4941&p_created=1204908170


Pretty much states what has already been said.

I do not see any audio equipment manufacturers placing PF correction devices in their equipment even though it may act as a means of increasing power quality for reactive loads.

"Power factor correction devices improve power quality but do not generally improve energy efficiency (meaning they won't reduce your energy bill)." --- From above link.

[satfrat]

http://energystar.custhelp.com/cgi-bin/energystar.cfg/php/enduser/std_adp.php?p_faqid=4941&p_created=1204908170


Pretty much states what has already been said.

I do not see any audio equipment manufacturers placing PF correction devices in their equipment even though it may act as a means of increasing power quality for reactive loads.

"Power factor correction devices improve power quality but do not generally improve energy efficiency (meaning they won't reduce your energy bill)." --- From above link.

You forgot the last sentence, Quote: "Energy savings alone do not make an installation cost effective."

[Occam]

Our test setup in lab was 3-phase. I have seen many computer power supplies that say they have built in power factor correction and thought that  it may be of some use with other applications.

Your test setup????

Certainly, a switching supply can often implement PF correction via integrated circuit control chips which along with other control functions offer PF correction. EU mandates require PF corrected supplies for > 60watts, although for the time being, audio equipment is exempt.

But the PF correction you've been describing is not the active, integrated functionality on more sophisticated switching supplies, but rather passive correction via the introduction of bulk capacitance. That passive correction, when ideally matched to a known inductive load, is quite effeicient, but that same passive correction when used to 'correct' and unknown and variable load, is a crap shoot, at best.

[Audiovista]

EU regulations do not mention PF, they put limits on current harmonics (2nd to 40th). Active PFC comfortably meets the requirements (most provide PF of 0.97 or more), but the harmonic limits (for lower power equipment) may often be met with less expensive, passive methods (PF of which is probably in the 0.85-0.9 range).

As for audio equipment - power amps for instance, I am not sure if PFC even makes sense - random current draw will result in harmonics that active PFCs can't do much about....

Capacitive correction, as Paul said, is good only for compensating inductive loads, and there are switched capacitor schemes that do a decent job. These don't do much for nonlinear loads (such as standard rectifiers/filters used in electronic equipment) and that's where active correction shines... for those who need it, in our homes we do not get penalized for using (or generating) kVAr.

[Niteshade]

So much for the power factor correction idea! A traditonal AC inline noise filter or some kind of power conditioner looks like the most appropriate way to go if someone requires it.

My test setup? It's been a while. I had my Motors & Control class in 1999 and don't remember many of the details. It was a great class, but we only had one class on it that went into the basic details. Unfortuniately, the information was never used again. This thread has been a good reminder of what it was about.

Perhaps a massive string of Bybees? 

The fractional ohm resistors that cost around $100.00 and are non-reactive......

[cryoparts]

FYI--Sonicweld (www.sonicweld.com) makes extensive use of active PFC in all of their newest generation of electronics.  I've seen the boards and their approach is very trick.

Peace,

Lee

I do not see any audio equipment manufacturers placing PF correction devices in their equipment even though it may act as a means of increasing power quality for reactive loads.

[satfrat]

I actually use a form of power correction on all my equipment with Ridge Street Audio Design's Z-der Blocks. Robert even made me up a 20a IEC unit for my BPT balanced power conditioner.


http://home.comcast.net/~ridgestreetaudio/ZderandBloomImages.html


Cheers,
Robin

[peranders]

saves money by increasing efficiency.

Not for you since you pay for energy and your meter doesn't measure reactive power. The electric company saves money since he get less losses in the wires.