WHAT IS POWER FACTOR OR PF - WHAT DOES kVA MEAN - WHY ARE kW DIFFERENT TO kVA - WITH WORKED EXAMPLES
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- Опубликовано: 15 сен 2023
- In this video from LearnElectrics, we will take a very gentle look at this thing called power factor, and show you how we use Watts and volt-amperes to help us look at how efficient a system is. Starting at a nice easy level, we look at what the different terms mean and how they work together in an electrical installation.
There are always lots of questions about power factor and some of them have included things like …
How can I calculate power factor and Watts?
What is power factor and how does it affect the installation?
And why are VA and Watts different, I always thought that V times A was Watts? And now it isn’t.
But before we start on working out VA and power factor, we will have a look at some basics on the subject of waveforms and resistive and reactive circuits. All good stuff, helpful, interesting, and nice and easy to understand.
This is video number 218 and to view all our videos type in LearnElectrics all one word into the RUclips search bar.
Visit our RUclips channel where we have many more videos on a wide range of electrical topics.
Dave, Thanks again. I’m going to watch this a few times so I totally absorb what’s going on. As a great philosopher once said, “It is not what you know, but what you understand. I want to become an electrician who understands & you make that journey much easier for me.
Stick with it, learn what you can. You have the right attitude, Dave.
I Appreciate Learn Electrics again for this easy to comprehend presentation. Great work, thank you.
Great feedback Danny, really appreciated, thank you. Dave.
Always makes more sense the way you do it! Thank you.
Glad to help, thank you.
Another smashing lesson from professor DAVE as I call him, putting in some more knowledge into our mental toolbox as usual 👌👌👏
Thanks for the support, really appreciated. Thanks for watching. Dave.
The beer analogy, is quite good and a nice explanation.
Glad you liked it. Thanks for watching. Dave.
Your a legend thanks Dave
Happy to help, thanks for watching. Dave.
Thanks so much for this, absolute gold!
Glad you enjoyed it, you're very welcome and thanks for watching.
thanks Dave , another clearly presented lesson
Glad you enjoyed it Edward, thanks for the support.
Another splendid and informative video..👍
Glad you liked it and I appreciate the feedback.
Great video Dave. Hope there will be a follow up video discussing the iron, copper and fixed losses that causes these inefficiencys and the ways on how to improve PF.
Its planned to do a follow up, yes. Watch this space as they say. thanks for watching. Dave.
Excellent Dave👌
Thanks Brian.
Thank you Dave
Thanks for watching, very much appreciated.
Another great video, Thanks again Dave!
Have you done anything on wiring PIR and Dusk to Dawn sensors into existing circuits with switches or without etc… ? Another thing would be connections in series and parallel.
Your style of programming watching is amazing, thank you again!
Have a look at these two videos
this one about two lamps in series
ruclips.net/video/Lrd7jwksqb4/видео.html
and this one about series and parallel circuits
ruclips.net/video/TtA94FEFIRM/видео.html
Thank you sir
Very welcome, thank you. Dave.
Quality video.
Much appreciated, thank you. Dave.
Well done, thanks for taking the time to share your knowledge. Is there a formula to find the amps on that nameplate at 13:10? I can’t seem to make sense of the amperage rating on the motor?
The amps are printed on the nameplate. Have another look. Thanks for watching. Dave.
Beer analogy is superb
We all love beer. Thanks for the feedback. Thanks for watching.
Merci à vous,vous etes très gentil
Avec plaisir et je suis heureux que vous avez apprecie la video. Dave.
Great video. Can I ask though I’ve come across various items and most of time they generally just show kva or Va rating so when choosing cable and breaker do you usually just work it out to that Va or Kva rating as that’s 100%? Thanks
Yes, using the VA figures is ok. Have a look at this video on cable sizes. Dave.
Great video and well explained. Thank you for making these amazing videos. I just have one question. Using the motor data plate shown on the video if the voltage (400) is multiplied by current (11) equals 4.4KVA. It’s lower than the true power shown (5.5KW). I thought the apparent power is always greater than the true power. What am I missing? Thank you.
There are some calculations that will be part of the second video involving root 3, or 1.71 and so on. Watch this space and thanks for watching this one. Dave.
Hi love the videos. Always come back to your content.
Ok to ask a question tho. Client is upgrading to 3 phase from 2 phases in the application it asks for the kva. The upgrade is for 10 flats.
Where would you get the figures for the equations if you don’t know what the main fuses will be. For example if you looking to fit a 315 amp 10 way distribution GFP10.
Would you put 315 and 400 v ?
Hope that’s clear enough. Thanks again
We don't run 2 phase circuits. either 3 phase or single phase. thanks for watching. Appreciated.
Love that Beer analogy Dave!
Never heard that one before haha
Maybe not Andy, but we've drunk plenty.
@@learnelectrics4402 that we have!
Fantastic explanation Dave. Im building a house at the minute and NIE are upgrading the existing transformer from 25 KVA to 50 KVA. DOes that mean 50000 volt amperes surely thats very high unless some is lost on the overhead cables plus its feeding other properties. I assume another transformer close to the build will step that down to 230 volts or near abouts to allow for voltage drop etc. DO you have a video on how electricity gets to a house etc.
Yes, the voltage will be stepped down to user friendly values. the reason the incoming voltages are so high is in order NOT to lose power in the overhead supply. I have thought of making a video on this, perhaps I should get it done. thanks for the prompt. Dave.
Thanks again,, i discussed the PF effect on the residual electricity bill,with several electrical engineers. The answer was no effect as we pay for KW not KV,,, do you agree with them ??
In domestics we pay by kWh. Thanks for watching. Dave.
Working early!!!
No, not me. Used the scheduler. Thanks for watching. Dave.
at 1.04, you should not say "Current, the Amps". It is Current, measured in Amps. Less importantly, a dimensionless factor is usually expressed relative to unity or '1' You do say this, but then slip into expressing it as '%' which is strictly incorrect and unnecessary. You know your stuff, but you tend to over-state things by mixing your terms in a way that could confuse. If folk don't get it they will re-wind. Good series though. Each topic is the right length, delivery has a good pace, and a lot of effort has gone into producing clear, concise graphics.
Thank you for watching.