Power and Reactive Circuits – Power Factor



Well to start off with I have a plasma screen, a lovely little Sony which gobbles up 440W – so for every two hours of usage I have to pay in R1.00 (equivalent to U$ 14 cents). This may not sound like a lot but remember this is the RSA, the land of plenty where this amounts to a lot, especially when Eskom is run by the government. You didn’t know that – well read your papers.

How to lose some noughts on your bill?

What is power factor? Something you did not read about at school unless you were the school schmuck!  Power factor is actually determined by the real power you are consuming and the apparent power, known as ‘S’. We will publish an application in the next 50 000 years (yes, apologies all round, but it’s coming, it’s coming  – Ed) which will show you what this is all about. Does your swimming pool pump have power factor correction? The chances are it does not. I spoke to the local swimming pool guru and he thought I was talking about the outlet water pressure. Moving to the chase. Your pump motor will show you the power factor, the mains frequency at that specific power factor and the VA rating (Apparent power). Unfortunately your pool pump motor (or any motor BTW) is an inductance. Read up on inductances and capacitances. In an inductance the volateg leads the current by 90 degrees. Shift this to 0 degrees by adding a capacitance of NEARLY the same value and you household current will decrease. Amazing! A marvel? No.  Read about more of this here:  Power in Resistive and Reactive Circuits.  (Creative Commons Attribution License) – millions of thanks to the authors, your website is informative, clever and extremely intuitive.  I am hoping to have one of these clever websites running soon, but first I must learn to read.

Your average Joe Soap is not interested in power factor – neither is your power commission unless you are drawing over 500 amperes or so from their substation. If you do go to the website and learn something from the above mentioned website (do,do,do) you will also find that you need to reduce the reactive power. There is nothing better than pure power.  Know anything about resonance? This will make your toes curl. Remember that resonance equals radio theory. Don’t try to reduce your reactive power so much that it equals zero my friend, you may have to deal with a lot of other more significant probs. The most important thing is to reduce your aparent power because that, sadly is what you are paying for. Would an electrician worry about this? No. Should you? Have a read. 

 

Power_Triangle

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