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PF correction devices, again

99K views 564 replies 92 participants last post by  hardworkingstiff 
#1 · (Edited by Moderator)
Hate to bring this up again but the Natioanal Institute of Standards and Technology (NIST)recently did a real study of these scams, er I mean devices so thought I would post link in what I hope is the last discussion we ever see on these PFM boxes.

http://www.nist.gov/eeel/quantum/power_121509.cfm

I hope this opens some eyes to the EC's out there slling these devices under the false belief that they offer any savings to thier victims, er I mean customers.

EDIT**Original link is dead. Here are the updates ones:
http://www.nist.gov/pml/div684/power_121509.cfm

http://www.nist.gov/customcf/get_pdf.cfm?pub_id=903669
 
#3 ·
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#6 · (Edited)
I just want to say that I've not brought it up for a while...I am still testing. I don't know if I am saving money or not. I love to test things. As the report says you would need to remove the capacitor when the inductive load is not in use for the reasons they said. I've said that like ...forever. I cannot climb inside my utility meter to see what is going on, but I CAN say that when the AC is on, the unit I made comes on with it and off, as well. The circuit that the AC is on does not change what it draws whether the PF unit is IN or OUT of the circuit. That is because it will always try to consume the power it was built to consume. With the unit in the system, the meter slows down, and draws 3 amps less from the utility. Other than that I don't have much to say. It's all in the meter.
 
#7 ·
The KVAR PU1400 was installed in my house 11/08. Power usage from 11/07 - 11/08 was 488.633Kw Power usage from 11/08 - 11/09 was 503.581Kw. Nothing was added electrically, actually a small amount of load was shed, as we switched from a 13 SEER A/C unit to a 19.2 SEER unit in 9/08. Also my Ice machine (large one, 450 lbs per day, was not on from 12/08 to 3/09. We have a good amount of motor load and I was told that I would save up to 30% on my electric bill, which I though was a bit far fetched, but figured it was worth the 325.00 I paid for the unit. After 2 or 3 months of it being installed, I knew it was a scam.
 
#9 · (Edited)
The KVAR PU1400 was installed in my house 11/08. Power usage from 11/07 - 11/08 was 488.633Kw Power usage from 11/08 - 11/09 was 503.581Kw. Nothing was added electrically, actually a small amount of load was shed, as we switched from a 13 SEER A/C unit to a 19.2 SEER unit in 9/08. Also my Ice machine (large one, 450 lbs per day, was not on from 12/08 to 3/09. We have a good amount of motor load and I was told that I would save up to 30% on my electric bill, which I though was a bit far fetched, but figured it was worth the 325.00 I paid for the unit. After 2 or 3 months of it being installed, I knew it was a scam.
As an electrician I would hope you would know better, basic electric principles are nearly non-existant in the EC world these days, guess thats why so many sell them and believe they work.
 
#16 ·
I once install a large capacitor bank in a factory that was a plastic blow molding operation.
I questioned that.
Mostly due to most of the load was used for the heating of the plastic..
Relatively few motors involved.
I have no idea who talked them into that one , but I am sure they will never recover the cost within the life of the bank and/or company.
 
#23 · (Edited)
#25 ·
Read it again, PF correction saves the homeowner nothing. They shift attention to thier other product and offer "testimonials" from customers that think they are saving energy. They shift attention to the UL listing, which has nothing to do with saving money, they shift attention to the energy star push, which they may get, because they do save energy, just not anything the homeowner will see on the electric bill.

The statement about saving the utilities energy is true, but not the homeowner.

Clever marketing, that is all.
 
#33 · (Edited)
Capacitors have been used for decades to correct lagging power factor caused by motors, but for homes, this is easily done at utility facility level.

What they can not do is correct power factor and line voltage harmonics caused by non-sinusoidal loads, most notably switching power supplies(computers, electronic ballasts, VFDs)

These issues are addressed through voluntary certification and legislation at device level using active power factor correction so the cause of power factor reduction that can't be corrected at utility level is reduced.


"80 Plus" for example is a voluntary certification program for computer PSUs that requires power factor correction, minimum efficiency standard and providing appropriate power quality to computer. Of course... they're not really meant to help the consumer... their partners include things like Bonneville Power Administration.

Some PFCs need sinewave to operate, and may not work right on stepped squarewave inverters or UPS. Some active PFC fluorescent ballasts and active PFC computers won't run on economical inverters/UPS while non-PFC CFLs and computer power supplies do.

We don't really have that many low power factor inductive loads at homes. The biggest inductive load is probably the AC condensing unit, but the load is fairly high and consistent, so PF is rather high unlike lightly loaded motors often found in industrial facilities.



So in conclusion, even if power companies started to bill its customers strictly on kVAh rather than kWh, these capacitor junk is utterly useless against poor power factor caused by electronics. They're only effective against lightly loaded induction motors, which we don't have many of at homes..
 
#39 ·
Regarding Continental Power Corp in post #34, its website claims its satisfied customers include municipal sewer facilities(which fall under public purchasing, so the records should be open).

I requested references and their contact, but it hasn't responded.
 
#40 ·
Regarding Continental Power Corp in post #34, its website claims its satisfied customers include municipal sewer facilities(which fall under public purchasing, so the records should be open).

I requested references and their contact, but it hasn't responded.
There are large institutions such as schools out there that swear that theirs are working and saving money. Who knows, the maintenance guy may be fudging the results. I am still checking and they at least don't seem to hurt anything if installed correctly.
 
#42 ·
Someone stopped by the American Legion post I belong to trying to sell one of the units. It was early in the day and the bar steward was the only one there so he took the brochure and sent the salesman on his way. The post has a 3 phase service and several large loads. Walk in cooler, beer and wine coolers, ice machine, commercial refridgerator, 2 AC units, and smaller refridgerator and freezer. It could be possible that one of these units could save a few dollars. I am not sure how soon the payback would be and I think the salesman quoted on a single phase and not a 3 phase.
 
#43 ·
Go through the last year of power bills. Is their power factor low enough to be charged a penalty or would they be given a credit for improving power factor beyond what it is now? PFC devices won't save you a dime on actual energy (kWh) charge. Unless the utility says improving your current power factor will reduce penalties or give incentives, its a waste of money.
 
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#53 ·
I am a bit late on this topic but to let you know you are not alone to scammers. Our supplier counters are always awash with the homeowner type of plug in device that purports to save energy. And it is surprising how many electricians fall for these sharp deals. For the homeowner - forget it. The energy saved on the balance of uncorrected inductive or capacitive loading you could hardly measure. If you are the owner of a sewing factory then this is something else entirely. The only known way to reduce costs for a domestic consumer that I am aware of is to use an optimised level of Voltage. This will require some smoothing device - and they are out there in the market place but are expensive and only opperate effectivly on resistive loads.

Frank
 
#58 ·
I am a bit late on this topic but to let you know you are not alone to scammers. Our supplier counters are always awash with the homeowner type of plug in device that purports to save energy. And it is surprising how many electricians fall for these sharp deals.
Frank
I can't speak for your side of the pond but in the US the reason is somewhere along the line it was determined electrical thoery was not needed to be an electrician. Bending pipe sems to be more important than a strong theory base knowledge.
 
#54 ·
If that is supposed to be an insult, I'll just look at the source of where it came and brush it off.

Unlike others, if someone makes a claim, I will listen to the argument before dismissing it. That seems to be a fair approach to me. Not sure what part of
...be interesting to follow the tested results to see what happens.
you thought was obvious to classify me as:

I suppose you're the type of viewer easily swayed by craft marketing as long as its made to look "real on field" no matter how flawed it is fundamentally.
I have admitted openly and honestly my limits in the electrical field. I know where I don't have expertise, and I do not claim it. Therefore, since I don't understand all of the "fundamentals" I will look at tested results. That is logical. What is not logical is claiming expertise in an area where you do not possess it, and then trying to defend it till you are blue in the face while it is obvious to all of those around you that you are incorrect.

Like I said, I look at the source and see it for what it is. I neither own one, nor plan to put one in, nor pitch them to others. I'd have to see tangible documented proof from an accredited government agency before implementing the solution. I certainly wouldn't take your word on it.
 
#60 ·
It's also an attractive and lucrative to scammers looking to take advantage of ARRA. It takes almost no capital equipment to cram some capacitors into a metal in the 'ol USA, so it qualifies as US Made.
 
#68 ·
I can only say that I have done lengthy tests...monitoring loads, and such, and in every test the current through my meter dropped by 3 amps with the device that I built installed. The meter slowed down by about .6 sec/revolution. If I am not saving money I don't care. I like to experiment, and that is what I am doing. I do realize that the majority of the change in current occurs when the AC/HP is on and that is why I isolated the device through contacts. I have no reason to exaggerate on something like this. I had originally been "GIVEN", at no cost to me, a PS1200 to prove or disprove. I proved that it would not save money if installed as the manufacturer recommends. Maybe we ought to change the subject...at least until someone brings it up again. There is nothing wrong with learning something new.:thumbsup:
 
#80 ·
I'm amazed that this is even a topic for discussion. It goes to basic AC electricity theory. The power factor is the cosine of the angle between voltage and current. In a purely resistive load like an incandescent lamp the angle is zero and the pf is 1. For the end user, power factor correction capacitors are used industrially on large inductive loads. One thing you don't want to do is correct the powerfactor to where it has gone past one and become capacitive. This is why even for industrial users where pf will not be monitored continuously the capacitor is located at the load it is serving so it is only connected to the network when that load is operating. Power factor correction capacitors reduce the number of KVA for a given number of KW if the power factor is less than one. Unless you are paying a penalty to the utilities for low pf, this is of no benefit to the user but even if it were, the savings would be negligable compared to the cost. It is a benefit to the utility because they transmit fewer amps for the same KW load and therefore experience less I squared R loss on their feeders and lower load on their transformers.

One recent trend is for manufacturers of electronic data processing equipment to incorporate pf correction caps in their equipment. This becomes an issue if pf passes one. Generally local on site generators do not like seeing loads that have a capacitive pf, they want to see an inductive load. The utilities don't like it either. The mnemonic device to remember is "eli the ice man." What this means is tht in a net inductive load circuit voltage leads current. In a net capacitive load current leads voltage. Generally pf rarely goes below 0.8 inductive. Net inductive load circuits are said to have a "lagging" pf which is what you want.

The only way to test a pf correction capacitor to see if it actually saves money is under controlled conditions. The variables of load are usually too great to determine if pf actually saved much money if anything under normal use. They do what they say they do but for most people it is a complete waste of money. Personally I've never installed one and never seen the need to.
 
#70 ·
I conducted the Brandeis University study that was mentioned above. I think it covers a lot of things that are being discussed here and it has measurements that back it up. Take a look at it if you doubt that the KEC is more than a capacitor:
http://alignment.hep.brandeis.edu/Lab/KVAR/
I don't know of anyone here doubting what it is. Forgetting about any monetary gain, are you saying they do not have an effect on a residential service?
 
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