Passive Power Factor correction

Has anyone have experience with something like this?
http://www.ndaenergy.com/power-factor-benefits.html

Martin Riddle wrote:

Has anyone have experience with something like this?
http://www.ndaenergy.com/power-factor-benefits.html

In short, it's a scam.
there is some truth behind power factor correction saving power, but it's not 10 to the totaly bogus 25% savings they claim.

Martin Riddle wrote:

Has anyone have experience with something like this?
http://www.ndaenergy.com/power-factor-benefits.html

Load of old garbage. Individual consumers don't need power factor correction as the power company doesn't bother charging it for them.
They should be prosecuted for FRAUD. Refer it to you local DA
Graham

Cydrome Leader wrote:

Martin Riddle wrote: Has anyone have experience with something like this?
http://www.ndaenergy.com/power-factor-benefits.html
In short, it's a scam.
there is some truth behind power factor correction saving power,

In industrial situations.

but it's not 10 to the totaly bogus 25% savings they claim.

But it doesn't affect the home consumer whose meters read only TRUE power and PF won't affect that.
Graham

On Oct 10, 10:45�am, n...@picaxe.us wrote:

I would appreciate info on power correction to reduce load on the emergency generator when powering the furnace blower - less load > less gas = fewer trips outside in the cold to refill.
Thanks, John-

If you can plug it into a Kill-A-Watt it will show you true Watts, VA (Volt-Amps) and PF (Power Factor). Power factor correction will raise PF towards 1.0 and reduce the VA closer to the Watts.
A bad power factor is somewhat like bad shock absorbers when driving down a bumpy road. The vehicle bounces up and down more than the road does. With a poor power factor some of the electric current bounces back from the motor.

On Thu, 9 Oct 2008 19:06:24 -0400, "Martin Riddle" wrote:

Has anyone have experience with something like this?
http://www.ndaenergy.com/power-factor-benefits.html

That old fraud again.
In a very simplified nutshell, a load with a power factor less than 1 draws both real power and "wattless" or reactive power. "wattless power" seems like a contradiction but its the slang used in the power industry. Wattless amps flow out of phase with the voltage waveform and are caused (usually) by loads that have an inductive component (electric motors, primarily) or (rarely) by loads with capacitive components (un-PF corrected switchmode power supplies, some types of fluorescent lights, etc.) The real amps and the wattless amps add quadratically to produce the total amps.
Here's the critical part. Revenue meters only measure REAL power (some of the new electronic ones also measure VARs [reactive power] but do not bill for it) and REAL power is what you're paying for. Large commercial customers can be billed for low PF (excessive VARs) but never in a residential or small commercial (200 amp) service. Reactive power simply flows through the lines unmetered.
Most VARs are lagging - that is, the current lags the voltage by some phase angle. What that box does is supply leading VARS to counteract the lagging VARS. That reduces the amps flowing through the circuit upstream of the box (which is what they show unsophisticated customers) but that reduction has essentially NO effect on the REAL power metered by the revenue meter.
I say "almost" because the extra amps flowing through the wire's low but finite resistance developers a little heat. This is real power and gets metered. The amount is tiny, though, a few watts at most.
The box contains ordinary motor run capacitors. Problem is, these capacitors are not perfect - none are - and so they dissipate a little heat themselves. That again is REAL power that is metered and billed for. Again, it is a small amount but it may very well exceed the amount of power saved by reducing the current in the low power factor house wiring.
Worse, the box supplies a fixed amount of leading VARs. When those VARs aren't needed by, say, a furnace fan motor, they flow back out the service entrance and to the utility network. The current flow through the conductors between the box and the meter causes another small voltage drop and therefore some heat generation. The amount of REAL energy consumed is undoubtedly small but it very well could exceed any "savings" caused by correcting low PF loads in the house.
In other words, having this very expensive box in place could and probably will cost you a few cents more a month on your power bill. I bet they charge a kilobuck or more for this box so that's money just pissed away.
There is only one instance where PF correction makes sense for small consumers. That is, when the wattless current is (on the verge of) overloading the service entrance. Even then, this box is the WRONG way to go about fixing the problem.
Let's suppose you have a store with lots of low PF pre-energy efficient fluorescent lights inside and lots of neon signage outside. Low PF fluorescent fixtures typically have a PF of around 0.5. Low PF neon transformers around 0.4. That means that the fluorescent lamps draw TWICE the current necessary to provide the fixture's wattage. The neon draws a little OVER TWICE the necessary current.
If lighting and signage makes up the bulk of your load and the total current is near or exceeds 200 amps then you'd be experiencing tripped main breakers, an overheating breaker panel and perhaps complaints from the utility.
The thing is, only half that 200 amp (assuming an average pf of 0.5 at the service entrance) is necessary to operate the lights and signs. The rest is lagging reactive amps that do nothing other than heat wires and trip breakers.
If someone like me comes in and corrects each low PF load by placing the appropriate capacitor across the load's power terminals so that the overall PF is now 1, only 100 amps is drawn from the utility. The other 100 amps are supplied by the capacitors that are scattered around the facility. I normally correct each neon transformer at its power terminals and each fluorescent lamp string (not worth the cost to do each lamp individually).
This process saves very little money on the power bill but it DOES eliminate the excess current draw, the overheating, the complaining from the power company and it opens up those 100 amps for other loads in case the store expands.
I would NOT use a box like that company is peddling. I use motor run capacitors which, bought wholesale, cost about $5 ea. Here's a photo of one
http://www.johndearmond.com/wp-content/uploads/2008/10/fan-11.jpg
I repeat, this procedure is NOT necessary and is NOT financially justified unless the service entrance and panel is being overloaded by low PF VARs OR your power company is threatening a low PF penalty charge. The latter is very very rare on 200 amp services.
Here's another situation. Suppose a business has a sign out on the street, located several hundred feet from the breaker panel. The sign is mostly neon. It has a 30 amp branch circuit run to it through either underground conduit or direct-burial cable. The sign is pretty much fully loading the branch, drawing a little less than 30 amps. Since the neon transformers have low PF (around 0.4), over half that current is wattless.
Now suppose the store operator wants to install a larger sign with more neon. The 30 amp branch is at capacity and running a larger one would require tearing up his parking lot, costing thousands of $$$ and leaving an ugly scar on his pavement. What to do?
We go into the sign and PF-correct each neon transformer (or buy high PF transformers that have the caps built in) in the new sign. With each transformer having a PF near 1, we can draw twice the real power over the same 30 amp branch. IOW, the sign can be twice as large while drawing the same current.
The sign will, of course, cost twice as much to operate so the cost savings is strictly in not having to dig up his pavement and run a larger branch. Presumably the larger sign will draw more customers and thus pay for the extra power consumption.
Making neon signs myself, I've run into this situation MANY times. Few sign shop operators understand the concept of PF so I've been able to "save the day" a number of times for sign shops that bought wholesale neon from me.
The only other common situation where correcting a low PF load makes sense is when you're trying to run the load from a generator that is being overloaded by the wattless current. We touched on that yesterday in another thread. In this instance, correcting the PF of the low PF furnace blower will allow the generator to handle the load AND power some other loads. It will also save fuel so if you're off-grid or experience frequent power outages, PF correction might be worthwhile, depending on your existing PF and how often you run your generator.
Pre-energy-efficient fluorescent lamps, some mercury vapor and HID lamps and lightly loaded motors (typically HVAC blower motors) are typically the only low PF loads in the house. Some microwave ovens are also low PF. Most fully-loaded motors have high PFs. Typical is the measurement someone posted recently of his refrigerator having a 0.95 PF. If you have one, a well pump may or may not be low PF, depending on how it is sized. A deep well pump in a shallow well is quite under-loaded and will have a low PF. The only way to know is to measure.
Let me repeat again, unless you're running out of service entrance capacity or are having to run the load using a generator, low PF simply doesn't matter around the house or small business.
If there is a lot of interest in this then I'll do a web page on DIY PF correction. However, unless you have a special circumstance such as those listed above, it's simply not worth the effort. It would take years for the tiny power savings to pay back the cost of even $100 worth of capacitors.
John -- John De Armond See my website for my current email address http://www.neon-john.com http://www.johndearmond.com <-- best little blog on the net! Tellico Plains, Occupied TN You can't turn [MS] shovelware into reliable software by patching it a whole lot. -Marcus Ranum

On Fri, 10 Oct 2008 10:16:03 -0400, Neon John wrote:

On Thu, 9 Oct 2008 19:06:24 -0400, "Martin Riddle" <martin_rid@verizon.net wrote:
Has anyone have experience with something like this?
http://www.ndaenergy.com/power-factor-benefits.html
That old fraud again.
In a very simplified nutshell, a load with a power factor less than 1 draws both real power and "wattless" or reactive power. "wattless power" seems like a contradiction but its the slang used in the power industry. Wattless amps flow out of phase with the voltage waveform and are caused (usually) by loads that have an inductive component (electric motors, primarily) or (rarely) by loads with capacitive components (un-PF corrected switchmode power supplies, some types of fluorescent lights, etc.) The real amps and the wattless amps add quadratically to produce the total amps.
[snip]
The only other common situation where correcting a low PF load makes sense is when you're trying to run the load from a generator that is being overloaded by the wattless current. We touched on that yesterday in another thread. In this instance, correcting the PF of the low PF furnace blower will allow the generator to handle the load AND power some other loads. It will also save fuel so if you're off-grid or experience frequent power outages, PF correction might be worthwhile, depending on your existing PF and how often you run your generator. [snip]
If there is a lot of interest in this then I'll do a web page on DIY PF correction. However, unless you have a special circumstance such as those listed above, it's simply not worth the effort. It would take years for the tiny power savings to pay back the cost of even $100 worth of capacitors.
John

I would appreciate info on power correction to reduce load on the emergency generator when powering the furnace blower - less load = less gas = fewer trips outside in the cold to refill.
Thanks, John

news@picaxe.us wrote:

I would appreciate info on power correction to reduce load on the emergency generator when powering the furnace blower - less load = less gas = fewer trips outside in the cold to refill.

How often does it trip ?
You just need to PF correct the blower. That's all. No 'central' PF.
Graham

On Oct 10, 2:27�pm, Eeyore wrote:

Jim Wilkins wrote: A bad power factor is somewhat like bad shock absorbers...
That is truly one of the worst explanations I have ever seen.http://en.wikipedia.org/wiki/Power_factor
The truth is, it's complex (in more ways than one). � � � �;~)
Graham

You try writing a simple explanation of absorbed vs reflected power without mentioning omega or the square root of -1.

Jim Wilkins wrote:

n...@picaxe.us wrote:
I would appreciate info on power correction to reduce load on the emergency generator when powering the furnace blower - less load = less gas = fewer trips outside in the cold to refill.
If you can plug it into a Kill-A-Watt it will show you true Watts, VA (Volt-Amps) and PF (Power Factor). Power factor correction will raise PF towards 1.0 and reduce the VA closer to the Watts.

It still won't affect your bill.
Oh, the furnace blower. He needs to measure that seperately but by the sound of it would not know what to do with the data.
It could also be 'start-up current' that's causing the tripping. In which case he needs more amps on the supply and a larger rated breaker. Or a better designed blower.
Graham

Jim Wilkins wrote:

A bad power factor is somewhat like bad shock absorbers when driving down a bumpy road. The vehicle bounces up and down more than the road does. With a poor power factor some of the electric current bounces back from the motor.

That is truly one of the worst explanations I have ever seen. http://en.wikipedia.org/wiki/Power_factor
The truth is, it's complex (in more ways than one). ;~)
Graham

generator to handle the load AND power some other loads. It will also save fuel so if you're off-grid or experience frequent power outages, PF correction might be worthwhile, I was following you until I got to this part.

I don't understand how PF correction would save much fuel. If the gererator is loaded to maximum with a 0.50PF load, isn't still only generating the REAL power?

On Fri, 10 Oct 2008 19:11:54 +0100, Eeyore wrote:

Jim Wilkins wrote:
n...@picaxe.us wrote:
I would appreciate info on power correction to reduce load on the emergency generator when powering the furnace blower - less load = less gas = fewer trips outside in the cold to refill.
If you can plug it into a Kill-A-Watt it will show you true Watts, VA (Volt-Amps) and PF (Power Factor). Power factor correction will raise PF towards 1.0 and reduce the VA closer to the Watts.
It still won't affect your bill.
Oh, the furnace blower. He needs to measure that seperately but by the sound of it would not know what to do with the data.
It could also be 'start-up current' that's causing the tripping. In which case he needs more amps on the supply and a larger rated breaker. Or a better designed blower.
Graham

Rather than willy-nilly placing caps acroos the motor windings,it seems more reasonable to look for a rule-of-thumb based on motor amperage/hp.
Other descriptions in the thread indicate that a smaller generator could be used if PF is properly corrected. Being able to use a smaller generator makes a difference in the fuel used.
I'm only looking for coverage of short-term outages - something requiring less than 10 gallons of fuel (worst outage in 20 years was 36 hours). More than that and I'll be closing off most of the house and burning wood. I've learned to build a fireplace load that lights with one match, burns at least two hours without any intervention, and heats two rooms even with a window partly opened for proper draft - not too bad for a city kid who's always had gas heat.
If there was a need for long-tem power, I would probably consider some combination of solar (inverter AC plus charge batteries) and a Listeroid powered generator (direct AC plus charge batteries after a few rainy/overcast days). At a typical haf gallon or less per hour for a Listeroid providing 2-3KW, 50 gallons of diesel would last a long time.
John

stu wrote:

generator to handle the load AND power some other loads. It will also save fuel so if you're off-grid or experience frequent power outages, PF correction might be worthwhile, I was following you until I got to this part. I don't understand how PF correction would save much fuel. If the gererator is loaded to maximum with a 0.50PF load, isn't still only generating the REAL power?

Now that's more complicated. If you're generating your OWN power then apparent power WILL be a factor.
But only IF. With gris power it mostly all gets lost in the wash.
Besides, were you planning on running any low PF loads ?
Graham
p.s. and learn to trim headers properly. I ihaven't a clue who said what.

news@picaxe.us wrote:

Eeyore wrote: Jim Wilkins wrote: n...@picaxe.us wrote:
I would appreciate info on power correction to reduce load on the emergency generator when powering the furnace blower - less load = less gas = fewer trips outside in the cold to refill.
If you can plug it into a Kill-A-Watt it will show you true Watts, VA (Volt-Amps) and PF (Power Factor). Power factor correction will raise PF towards 1.0 and reduce the VA closer to the Watts.
It still won't affect your bill.
Oh, the furnace blower. He needs to measure that seperately but by the sound of it would not know what to do with the data.
It could also be 'start-up current' that's causing the tripping. In which case he needs more amps on the supply and a larger rated breaker. Or a better designed blower.
Rather than willy-nilly placing caps acroos the motor windings,it seems more reasonable to look for a rule-of-thumb based on motor amperage/hp.
Other descriptions in the thread indicate that a smaller generator could be used if PF is properly corrected. Being able to use a smaller generator makes a difference in the fuel used.

Where the hell did (personal) generators come into this ? It's an entirely different ball game.
Graham