Hi Gary, I was pretty suspicious of what the unit was claimed to do so I didn't give them any money. It's good that we have a reflector like this one with 3000 + members on the list that can give their $0.02 as well as their technical expertise / opinions.
Thanks for replying to my original post. Don, KD9PT ----- Original Message ----- From: "Gary Schafer" <gascha...@comcast.net> To: <Repeater-Builder@yahoogroups.com> Sent: Wednesday, February 11, 2009 3:43 PM Subject: RE: [Repeater-Builder] OT Power Factor > This is funny. All they appear to be doing is placing a capacitor across > the > line at the service panel which gives some power factor correction to > motor > or other inductive loads. But that correction is AT THE POWER PANEL which > is > only inches or a few feet at the most away from the meter. > > If you are not being billed for reactive power but only for real power > consumed, as you are in a typical home, then it does absolutely nothing > for > you. It does not lower the current in your motor and does not help prolong > its life. It only lowers the current going thru the meter. And since that > extra current is reactive it cost you no more or no less whether it is > there > or not. > > The other thing is, if you have no motors in inductive appliances running > that capacitor is still across the line drawing CAPACTIVE reactance > current. > Just the opposite of when the inductive load is on by itself. > You would need a capacitor reactance value to match the inductive > reactance > value to fully cancel any reactive current. > > Not that this hurts anything on you electric bill as you still get billed > only for real power used and not reactive power. > > You have just given away $299.95. > > 73 > Gary K4FMX > > >> -----Original Message----- >> From: Repeater-Builder@yahoogroups.com [mailto:Repeater- >> buil...@yahoogroups.com] On Behalf Of Mike Reed >> Sent: Wednesday, February 11, 2009 1:42 AM >> To: Repeater-Builder@yahoogroups.com >> Subject: Re: [Repeater-Builder] OT Power Factor >> >> The device works by changing the voltage waveform to get the most work >> for >> the least energy. NASA came up with idea many years ago, and it does work >> well. I think this was designed more for household appliances and such, >> not >> repeater systems, unless you are counting the cooler that holds the >> 807's... >> 73 >> Mike - N7ZEF >> >> ----- Original Message ----- >> From: "Don Kupferschmidt" <d...@httpd.org> >> To: <Repeater-Builder@yahoogroups.com> >> Sent: Tuesday, February 10, 2009 1:44 PM >> Subject: Re: [Repeater-Builder] OT Power Factor >> >> >> Hello group, >> >> I need to chime in here and ask about a device that being sold as an >> enhancement for saving electrical energy in a residence. >> >> The device is called Power-Save 1200 and you can see it at >> www.power-save.com. From what I can glean from the web site it's a power >> factor correction device that attaches to the load center wiring >> panel.via >> 3 >> wires; 2 are attached to a dedicated 20 amp 2 pole 220 volt circuit >> breaker, >> the other remaining wire is attached to ground. The instructions go on >> to >> say that this device is designed to condition all power consumed by >> inductive loads (electric motors) in the home regardless of installation >> location. >> >> Their web site states: SAVE UP TO 25% ON YOUR MONTHLY ELECTRIC BILLS! >> (Direct quote). There is a video on the web site that shows a volt / amp >> meter reading before and after the device is activated. The unit sells >> for >> $299.95 + shipping & handling. The dealer who told me about this device >> states that the unit will pay for itself over time. >> >> My brother in law is an electrician and we have gotten into a lively >> discussion about this device and the theory behind it. I say that while >> the >> device will probably work as advertised, it may not provide a complete >> savings to the owner as it is attached to the load center and not the >> individual motor. In essence, isn't the power company getting some >> benefit >> of this device since it's attached to the grid via the breakers which are >> being fed by the power company? >> >> TIA for your comments. >> >> Don Kupferschmidt, KD9PT >> >> >> ----- Original Message ----- >> From: "Eric Lemmon" <wb6...@verizon.net> >> To: <Repeater-Builder@yahoogroups.com> >> Sent: Monday, February 09, 2009 8:09 PM >> Subject: RE: [Repeater-Builder] OT Power Factor >> >> >> > Tom, >> > >> > Excellent questions! The first is easy: Residences and light >> commercial >> > occupancies have meters that measure real (true) power only. That's >> > because >> > only real power does work, and that's what you are paying for. The >> > classic >> > kWh meter with the spinning aluminum disk was perfected by Ferraris and >> > Shallenberger more than a century ago, and millions are in service >> today. >> > The most recent improvement is a magnetically-levitated disk that >> > nearly >> > eliminates any errors due to bearing friction. A revenue-grade kWh >> meter >> > is >> > extremely accurate, and very seldom requires service. >> > >> > True power is consumed only when the applied voltage and the resulting >> > current are in phase. In this specific case, volts times amps equals >> > watts. >> > When the current is not in phase with the applied voltage, we enter the >> > mysterious world of apparent power, which is expressed as volt-amperes. >> > Nearly all apparent power seems to be consumed by inductive apparatus >> such >> > as motors and transformers, except that such currents are returned to >> the >> > source as the magnetic field collapses. Suffice it to say that the >> > current >> > actually flows in the circuit, but it does no real work. When the >> > power >> > factor (PF) is poor, a lot of current flows in the circuit that must be >> > provided by the utility through larger diameter wires and bigger >> > transformers. Since PF is the ratio of true power to apparent power, >> the >> > utilities are always looking for ways to keep the PF close to unity, so >> > that >> > they can put off installing thicker wires and bigger substations. As >> > an >> > incentive for heavily-motored industries to increase the PF, some >> > substantial penalties are levied on those who don't correct their PF. >> The >> > easy way to increase the typical PF is to add parallel capacitance so >> that >> > the inductive reactance is compensated by capacitive reactance. The >> goal >> > is >> > to get the PF above 0.95. >> > >> > Another reason for adding capacitors across the line is for voltage >> > regulation. In rural areas with long distribution lines- usually at >> > 12,000 >> > volts- the voltage drop due to reactive currents can be significant. >> The >> > utility will add capacitor banks every few miles to help keep voltage >> drop >> > within narrow limits. This is as good a time as any to state that the >> > standard nominal utilization voltage in the United States is 120/240 >> > VAC on single-phase systems, and 120/208 VAC on three-phase systems. >> > There >> > hasn't been "110" or "220" in this nation for more than half a century, >> > but >> > some (usually older) folk still use those terms. >> > >> > The standard kWh meter does its magic by using a simple principle. The >> > torque on the aluminum disk is caused by two coils (or sets of coils) >> that >> > create a combined magnetic field. One coil creates a magnetic field >> > proportional to the applied voltage, while the other coil creates a >> > magnetic >> > field proportional to the line current. When both voltage and current >> are >> > present, the disk spins. A small permanent magnet acts as an eddy- >> current >> > brake, and ensures that the speed of the disk's rotation is exactly >> > proportional to the product of voltage and current that are in phase- >> true >> > power. The disk is geared to a register that records the revolutions >> over >> > time, resulting in power times time- energy. >> > >> > The rotating-disk kWh meter is being replaced with all-electronic >> > meters >> > in >> > many areas. Such meters can record reactive power usage, and also >> record >> > the times that peak demands occurred. Some really fancy electronic >> meters >> > can be remotely polled with a wireless system, so the meter reader can >> > drive >> > by the house or business and get the data on the fly. Carrier-current >> > data >> > transfer systems are now in use that allow the utility to read meters >> from >> > a >> > central office that is miles away. Not only does the utility not have >> to >> > set meter readers out into rural areas, but any power outage is >> > immediately >> > revealed due to the loss of data. >> > >> > Back to your original question about your customer's motors. If he is >> not >> > being penalized by the utility for excessive reactive power demand >> (i.e., >> > low PF) then he will save nothing. However, the judicious application >> of >> > capacitors may improve the voltage regulation within his building. >> > Some >> > mountaintop repeater sites have a power feed that is many miles long, >> and >> > voltage drop caused by air conditioning and power supplies can be >> > significant. Some older Motorola and GE station supplies are not very >> > efficient and have low PF when lightly loaded. The typical site >> > owner/manager is usually not a power engineer, and may be ignorant of >> the >> > significant inefficiencies of a low-PF power system. This may exist >> > for >> > years without anyone doing anything about it, leading to recurring >> station >> > problems and poor power quality. The national standard for nominal >> > utilization voltage is 120 VAC +/- 5%. If the receptacle voltage goes >> > below >> > 114 VAC or exceeds 126 VAC, something needs to be done. >> > >> > 73, Eric Lemmon WB6FLY >> > >> > >> > -----Original Message----- >> > From: Repeater-Builder@yahoogroups.com >> > [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Thomas Oliver >> > Sent: Sunday, February 08, 2009 11:43 PM >> > To: repeater-builder@yahoogroups.com >> > Subject: [Repeater-Builder] OT Power Factor >> > >> > Question for any electrical engineers out there. >> > >> > Are the meters on the side of buildings metering real power or apparent >> > power? >> > >> > Is power factor correction worth doing if the power company is not >> dinging >> > the customer for low power factor? >> > >> > This article >> > >> http://powerelectronics.com/power_management/motor_power_management/705PET >> 23 >> > .pdf >> > >> <http://powerelectronics.com/power_management/motor_power_management/705PE >> T2 >> > 3.pdf> talks about residential power factor correction and my >> conclusion >> > (from this article) is the savings would never be recouped. >> > >> > Second conclusion is the only benefit with correction is the wires >> between >> > the source and load don't heat up as much. What about the wires in the >> > motor >> > or transformer? do they also heat less? I would think so. >> > >> > Third conclusion is by correcting power factor you are helping the >> utility >> > company more than yourself because these phase differences "standing >> > waves" >> > exist all the way back to the power generation source therefore the >> > utility >> > lines have more loss due to their greater length than the customers >> > building >> > wiring has. >> > >> > The reason I am researching this is a customer of mine has roughly 50 >> > hp >> > of >> > total motors in his shop and wanted to know if he could save 30% on his >> > electric bill like some salesman of power factor correction black boxes >> > told >> > him he could. >> > >> > I realize I am going to have to look at his energy bill to see if there >> is >> > a >> > charge for low power factor and maybe call the utility company to see >> > if >> > he >> > will get a lower rate if he adds PFC devices >> > >> > >> > tom >> > >> > >> > >> > (\__/) ... >> > (='.'=) >> > (")_(") >> > >> > >> > >> > >> > >> > >> > ------------------------------------ >> > >> > >> > >> > Yahoo! Groups Links >> > >> > >> > >> > >> >> >> >> ------------------------------------ >> >> >> >> Yahoo! Groups Links >> >> >> >> >> >> ------------------------------------ >> >> >> >> Yahoo! Groups Links >> >> >> > > > > ------------------------------------ > > > > Yahoo! Groups Links > > > >
