How do to size a capacitor for Power factor correction
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- Опубліковано 15 вер 2024
- If you think sizing a capacitor for power factor correction is hard? You'd be wrong. It is so easy that even I can show you how in less than 15 minutes. Power factor seems like some mystical event when in fact it is very easy to determine.
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This has been of so much help to me. Thank you so much.
At 5:48 when you calculate amps from VA, you divide VA by Volts. Do you not also need to divide by sqrt of 3?
hi great vid but i have a question. I have no efficiency or power factor rating on my motor so how do i calculate input power. Thanks much appreciated
Well done chad!
Happy new year.
Regards mg.
awesome video. thanks for taking time to explain
Can you please make a video to explain how comes and generators have power factor? I thought only loads have PF, not generators. Also, is it possible to correct PF in generators? Thank you
Awesome again Chad love it!!
Thank you.Perfect Job.
Can you show us how to doit on the calculator?.
very well explained
Could you use a motor run capacitor for power factor correction across the 230v mains?
Thank you
Means a lot to us student struggling during COVID-19 .
After some many videos and examples this makes sense.
This helped so much, thank you !
How did you determine the circuit was an inductive circuit, where the current lags voltage? You just declared it was so, with out explaining how you concluded that through mathematical analysis.
How do you calculate the capacitor size, in farads, once you calculate the amount of kVAR you need to add to inject into your system?
When you are looking at +/- VAR of your system. Are you referencing the load or the source that is adding or subtracting VAR to the system to determine if the system is Leading or Lagging based on the +/- VAR of your meter.
A motor is always inductive because of the windings.
Industrial capacitors are often rated in KVAR for this type of service. There is a formula to determine the correct capacitance in microfarads, but it includes the voltage, so you need to know that as well. Most factories and industrial plants are inductive because of all the motors and machinery. Most computer and data centers are capacitive because computer switching power supplies are capacitive.
Thanks man, this was great review
your lacking something... you should show how many farad should the capacitor
You're lacking something too...
Once you already known the value of the reactive power the value of the capacitor is going to be c= q/w*(vrms)^2, where q is your reactive power, w is 2Pif
@@Van119903 I have a question
Q should applied on kvar or var to get the result in micro farsf
Regards
@@ramzishabo8311 q must be in var, hope it helps you :)
thank so much, sir that was helpful
Using the information that popular little "KILL A WATT" device gives, can you calculate the proper size capacitor (in uF) to improve PF?
did you find the formula ?
If I have 110 volts and a water heater element 16.42 uhenerys, how do I find the right cap.
Very good video and learnt a lot. What about if premises doesnt have motors as such, but consists mainly of Aircon, Lights, Ceiling Fans and sockets do we still need Capacitors for correction of PF?
There are lots of motors in aircon for compressor and 2 fans, and of course in the celing fans
So is power factor correction needed?
Interesting... Great job....
And u didn't mention load B & C specifications but u calculate
Are u assuming remaining specifications
what is the capacitance of the capacitor required ?
Take this DC formula: power = voltage * voltage / resistance. It generalizes to reactive power and reactance in an AC system. Substituting and solving gives: reactance = v^2 / reactive_power. I'll use the convention that capacitors are a negative reactive load. (i.e. they "supply" reactive power)
0.6 kV squared is 0.36 kV^2. Divide by -31.8 kV * A.
Calculator and cancelled kV gives: -0.0113 kV / A. The ohm is volt/amp and I adjust the scale: -11.3 ohm reactance.
The same computation gives -53 A (reactive) current.
The reactance of a capacitor is -1 / (2pi * f * C). Solved for capacitance: C = -1 / (2pi * f * X). Now substitute in units. -1 second / (2pi * 60 cycles * -11.3 ohms). 2pi = 6.283.. 1/cycle. Calculator and units cancellation: 0.0002343 seconds / ohm.
Manipulate the unit: sec / (V / A) = sec * A / V = coulomb / volt = farad. 0.0002343 F.
So we need a 234 microF capacitor rated for 600 V AC nominal. It's wired line-to-line, so at least safety class "X." It will continuously supply 53 A of reactive current, so its branch circuit will need a normal-duty 70A breaker or a 100%-duty 60A breaker. I don't know if code allows a 53A conductor, but I wouldn't be comfortable with that because a class-X capacitor may draw excessive current when it fails. I'll bet this is an expensive part - upgrading to class Y might be too expensive.
I'm not a professional, just a curious autodidact. Please consult with an electrical engineer and/or get your own degree and license before wiring and energizing anything that's measured using tens of kVA.
start: 1:42
but a capacitor has a value in pharad not var???
capacitor for Power factor correction
Start here: 1:40
if you can improve the power factor to say 90% or more why not just make it a hundred percent? is it possible to totally get rid of the reactive power to make the system lossless?
It becomes increasingly more expensive to improve it by 1%, you'd need to install many capacitor banks and synchronous condensers throughout the system with very little benefit because the installation costs would cost more than the power losses themselves. You might also introduce issues of parallel resonance which would cause dangerously high voltage.
Most will calculate for a .95 PF to consider the logical inefficiency of components, resistive and/or harmonic, and cost threshold to go higher. The right value cap will lower the angle by shifting the v & a phases into sync. Lots of math, but check this out for shop tools. ua-cam.com/video/TPqXNLkJTJM/v-deo.html
But, you didn't calculate the capacitance you need across the circuit.
Can you consider a case where the capacitor consumes some active power? A practical capacitor will consumer some active power, which may not always be ignored.
Could a capacitor be installed in a single phase system to acheive the end result of a lower electric bill?
Without getting into specifics, the short and sweet answer to your question is NO! Let me clarify a thing or two... first off, yes - you most certainly could have a capacitor installed on your electrical system... However, it's highly unlikely that the addition of capacitors to your electrical system would be beneficial to you in the slightest bit because I doubt you have anything in your house drawing huge amounts of current that is out of phase with the supply voltage(thus resulting in a poor overall power factor) such as is often the case in industrial settings with numerous large motors being operated on a continual basis... In fact, the cost of installing such a device by a licensed electrical contractor would far outweigh any benefit you would see because there's likely nothing to correct in the first place.
pasqualeredo good answer, except the cost of my own skill set. Why would I pay my boss to have me do electrical work for myself?!? Lol. Seriously, good answer otherwise.
+John Rice Thanks...
Sir I've subscribed your channel but I didn't turn up Bell icon.... For that to be done you need to do me a favor, it would be more excellent if you have showed up formulas visually.... It would help me for my exam preparation
Tell me sir how calculate capacitor value finally
And the capacitor rating will be ? I'm estimating it to 234uf, am I close ?
that is what i got
[-|(Voltage of cap)|^2/Xc]=(Q-reactive);
[(600^2)/Xc]=31.8k;
360000/31800=Xc;
11.32=Xc
Xc=-1/(2*pi*60Hz*Cap)
11.32=-1/120*pi*Cap
Cap=2.343*10^-4
Cap=234uF
Thanks for your time Jorge. It's always good to validate our answers with someone else. It's sad that Chad didn't take the time to answer, knowing that other people asked for the value too. Perhaps the "capacitor sizing" is an action limited to determine the VAR rating and not the actual capacitor's capacitance value, who knows. Personally I find it disrespectful when a person is posting a clip but doesn't take the time to answer few questions. It's simply not professional and is something to avoid if you run a business and you want to bring customers.
well since you posted your answer it made me more confident that my answer was right and since some people wanted to know the capacitor size, I decided to help so that's why I showed the steps. Yeah, it was annoying that the answer wasn't posted but then again it made me go find it myself luckily I had the resources. I'm not gonna lie it was a good video. I learned that in order to improve efficiency in loads a capacitor can be used which I think its pretty amazing lol
This is what we need to do, search around in order to find the answer. However, this video should be considered as an example, allowing people to somehow practice and evaluate their level of understanding and mastering of the material. Regardless of the subject you're studying and try to master, when we're are at the first stages in the study process, we somehow need confirmation that we actually understood the material and are applying the theory adequately. Confirming that you're on the right track or explaining you where you failed, is part of the instructor / tutor mandate. I'm not putting down the effort made here to assemble the information and make this video, however when we go to the academy's website we see something like "You are never left alone. Any questions are answered ASAP" and relate this statement to what is happening here, I'm questioning the fellow's sincerity. He might be very knowledgeable but it must be understood that sharing that knowledge is a skill on its own and if not done properly a lot fewer people will benefit from that knowledge.
Nice job!
How to make DC to Ac without using transformer
I would say an oscillator switch, Digital signal
Generally speaking, the devices converting DC to AC are known under the name of inverters. As far as I know, most inverters, not to say all of them, do require a transformer. Perhaps there are scenarios where they aren't needed, but I'd be doubtful. What would the generated AC voltage be used for in your question ?
You could use a DC motor which spins an AC generator.
Good explanation but why did you use proper formula
I and KVA relation actual formula
I=KVA/(1.732×V)
But you use
I= KVA/V
That's for 3 phase
figuring out by calculator tells you something different (waste of time)
Why calculate the capacitor value when you can give half a answer. That's like putting a meal together and not cooking it. The wonder of education always misses the punchline.
The title of this hurt my head how do to size a capacitor.... What
ikr lol
Don't waste time sir... complete what u say
Hes sooorry boys hes clearly canadian a