Power factor correction in AC systems

I experiment by attempting to correct the poor power factor of an AC circuit.

Category:

Science & Technology

Tags:

• volt-amps
• VA

[H8ISGR8]

I don't understand these videos that try to debunk the Power Correction devices. As someone else pointed out, If the devices are telling the utility meter that less amps are being drawn, which calculates to less wattage the meter is reading, then that would contribute to less kWh. If you are cutting down on kWh, then your utility bill is less. Right??? V*A=W. If you are cutting Amps, then Watts go down as well. Less Watts equates to less kWh.... Right???

[vegmatic1966]

@H8ISGR8 No. V*A=VAR (volt amps reactive) in AC systems. Residential meters don't read VAR, they read only the non reactive portion, thus correcting the reactive current has no effect on the meter reading. If I could get my hands on a utility meter, I'd make a video and put this to bed for sure.

[H8ISGR8]

@vegmatic1966 well get a utility meter and show it!! there are hundreds of videos claiming these PFC devices are saving people money.. As I see it, if the meter is seeing only 2A of power being used rather than 5A, at 120V. That's 240W as opposed to 600W.

[vegmatic1966]

@H8ISGR8 Slick salesman make a lot of claims. What you see and what is real are two different things. If you don't understand what I wrote above then there is no point in explaining it further. You need understanding of reactance in AC systems to understand why there can be a difference in current draw yet the utility meters shows the same power usage.

[jfoakley12]

Nicely done. Now, regarding residential billing you are absolutely correct - residents don't pay PF penalties. However, reduced amperage slows down the electric meter regardless - you still save money. People who have homes with central AC, pool/hot tub motors, cir fans, etc. will greatly benefit. Our company has well over 200K units in operation - they work. Sorry.

[vegmatic1966]

@jfoakley12 Residential meters measure true power. They can't read the reactive current portion, thus PF correction has no effect on the electricity meter. The residential user sees no money savings.

[Zenseivideo]

@Zenseivideo

This is for AC systems, of course.

[Zenseivideo]

@vegmatic1966

Hello... I have a small correction here.

S=V*A = VA, Real effect

P=V*A*cosv = W, Useful effect or resistive effect, this is what your meter shows and what you pay for.

Q=V*A*sinv = var, this is the reactive effect

And in 3-phase, you multiply by √3.

[HillOrStream]

@totosql I've been wondering about these new digital meters too. Specifically, if they can run backwards like an old meter if power is fed back in to the grid via a "grid tie inverter" fed by wind or solar power.

[quantumbits]

Respond to this video... A Local capacitor near the motor may theoretically improve efficiency though. Since the peak amp draw is spread out over two 1/4 cycles, it could compensate for resistance in the supply line. I might be inclined to agree with @ashtweth.

[quantumbits]

@laserrod1 You are right, the Meter measures VA. Point is, it measures voltage and current throughout the cycle and sees no difference between a resistive, capacitive or inductive load. The capacitor you add in effect STORES energy it pulls from the line, during the lead (first 1/4 wave part of the cycle as it charges. Then potentially, that energy is used by the motor in the lag or second 1/4 wave of the cycle as it partially discharges the capacitor.

[lolsypussy]

@vegmatic1966 hey man can you give me the diagram of that power saver? thats a nice demo right there.

[ediscover]

In the jurisdiction I live in, the power company has reactive power surcharge for commercial and industrial, but not residential. Now that means that correcting the power factor will save money on the surcharge, and in addition, save money on lowering pure watts. For the residential side, there is no gain for the surcharge because the power company does not surcharge, but a savings on true watts is still realized by correcting the power factor. Voila!

[laserrod1]

Folks

Don't listen to Vegmatic. Powermeters measure VA. So that means you will be overbilled if any load has a uncorrectable lead or lag power factor. FACT: Plug in a 100 uF AC motor run cap.into 120v outlet, it will measure 540 watts on meter. No power is used, cap will not heat up.

I reduced washer motor draw installing parallel120Uf cap. 641watts less meter draw!

Vegmatic dude;. do everyone a favor and verify what you claim b4 U do video.

[ashtweth]

it actually helps stop Dirty electricity research dirty electricity.If you reduce your amps you reduce your total wattage how can that not be a saving? PF boxes can work in the home it also saves your appliances life