Watts vs Volt-Amps - huh ??
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PF is no ta huge problem for TSW inverters, but can be a major problem for MSW inverters. However even TSW inverters can have a problem for example running a lot on non linear loads like switching power supplies found in Desktop computers and cheap CFL light bulbs where PF can be .6 or even less. Most TSW inverters can only handle .8 PF at full power. -
While a residential connection does not usually have a PF penalty added to their bill by the Utility, a low PF means they have losses in their electrical system. These losses will use up some of the total available kva of their transformer capacity in their inverter.Leave a comment:
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Power factor (PF) is one of those measurements that have no effect on 99.9% of people. Most people buy a AC or refrigerator or microwave oven without ever needing to know their PF.
Grid power can cope with just about every residence having some devices with far from perfect PF.
Its only a concern to the following electrical engineers designing big industrial factories and similar, power companies charging those factories,and when you are into using off grid solar power for your residence.
To most of the people that need to get PF as close to 1 as possible are off grid solar power users. The reasons being that "bad" PF wastes your battery/ies power. Less run time from any given battery capacity.
If the old standard of assuming PF of .8 then you wont go far wrong in estimating your battery power usage.
PF is really one of those measurements like Lumens ..If your room is not bright enough you dont go checking the Lumens ,you just go upgrade your existing 60w lamp for a 100w one...You get the idea.Leave a comment:
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Power factor (PF) is one of those measurements that have no effect on 99.9% of people. Most people buy a AC or refrigerator or microwave oven without ever needing to know their PF.
Grid power can cope with just about every residence having some devices with far from perfect PF.
Its only a concern to the following electrical engineers designing big industrial factories and similar, power companies charging those factories,and when you are into using off grid solar power for your residence.
To most of the people that need to get PF as close to 1 as possible are off grid solar power users. The reasons being that "bad" PF wastes your battery/ies power. Less run time from any given battery capacity.
If the old standard of assuming PF of .8 then you wont go far wrong in estimating your battery power usage.
PF is really one of those measurements like Lumens ..If your room is not bright enough you dont go checking the Lumens ,you just go upgrade your existing 60w lamp for a 100w one...You get the idea.Leave a comment:
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The two areas that you might look into if you want to learn more about power factor are peak rectification and complex impedance. Peak rectification refers to devices that only take power during a small part of the AC waverorm (requiring an inverter that provides a higher peak power) and complex impedance describes loads whose current waveform is not completely in sync with the voltage waveform. Both are more difficult for an inverter to drive, but modern inverters are designed with non-ideal loads in mind.Leave a comment:
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PF
As I said I am a new to this and perhaps I will take some time to get to an intermediate level of knowledge which will probably be where I peak in this particular field of study. I know my own capabilities and where my strengths lay.
My main hobbies are gardening and racing Go-karts, perhaps I know enough about them to teach some of you electrical guys a thing or two!!
Is knowing PF critical for me at this point or useful for me to understand?Leave a comment:
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Cheers!!
I have to disagree with you SK, just because many of the contributors on this site have little electrical knowledge it doesn't mean we have ZERO knowledge of algebra or mathematics in general. I have to say that since joining this very interesting site I have learned a huge amount, I am taking an online course in Basic concepts in Electricity, I have modified and greatly improved my off-grid setup in my shed and I have a new interest in life now. I can safely say now, that I know and understand the meaning of many of the electrical terms that you commonly use, however when reading this page I realize there is a huge amount that I do not know but that only inspires me to study more (I do have plenty of spare time these days). I thank all of you gurus for your undying patience with us DIY'ers!Leave a comment:
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My bad, inetdog and Sunking, sorry. I knew it didn't feel right dividing by 0.8. The "standard" correction should be VA * 0.8.
randlLeave a comment:
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You could measure the actual power use of each load. If you're calculating a hypothetical load, my electrical engineer friend and my quick read on this topic both tell me that accepted practice is to divide VA by 0.8. If VA=1000 then you would correct to 1249 Watts. This estimate is apparently well accepted but, of course, it could be low for a purely reactive load.Leave a comment:
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Originally posted by martin1025how can we calculate this and any proper to change ............Leave a comment:
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There's a good, concise explanation of power factor in the August/September 2012 edition of Home Power magazine. It discusses resistive vs. reactive loads, shows an example of in phase and out-of-phase reactive load plots, mentions what sort of loads will have high power factors, etc.
The trig explanation isn't too helpful for those who don't see the plots...Leave a comment:
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asking questions about power factor (why does my 1/2 hp motor draw 1,000 watts) and they figure it out, our work here is done.Leave a comment:
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