Whole house active power factoring solutions?

jcheiljcheil Solar Expert Posts: 722 ✭✭✭
Does anyone know of a company that sells an affordable (and I know that term is relative) active power factoring solution for an entire (off-grid) house? Or, would it be even worth it?

I know in the case of running from a generator, my non-power factor correct devices (especially the charger) pulls significantly more power from the generator than it needs to, as well as any of the other inductive devices in my household (i.e. refrigerator, A/C, fans, etc.).

I guess my thought was that wouldn’t this inefficiency also plague the power being drawn from an inverter? And if it could be power factor corrected then in theory the inverter would be putting out less (because it would all be real used power) and thus pulling less from the batteries.

And if also applied to the battery charger, would save fuel since it would finally be at near 1.0PF instead of .65PF.
Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html

Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Whole house active power factoring solutions?

    No. It is a waste of money.

    For one thing, most of those "whole house" PF conditioners are just a capacitor. This works on a "per load" basis providing you get the right value capacitor for the particular load (and in truth only induction loads like motors will benefit from this). But a household's PF shifts depending on what is on at the time, so it is never consistent enough to benefit from a single value capacitor.

    There are 'active' PF correcting devices which judge the PF and change accordingly. Needless to say they are very expensive.

    For the average home it is a worthless investment because you are not charged for PF adjusted power. For generator or inverter supplied you just live with it. This is why inverters' output is measured in Volt Amps, btw. It has no difference on the amount of power pulled from the batteries as that will always be the 'real' power even if the AC side is adjusted.

    If you find it is a really big issue you can try correcting the devices on an individual basis, but be advised you are in for a lot of experimentation with running caps (not starting caps) on motors and having a look at the K-A-W PF reading as you try different values to see which gives the most improvement. It will ease the load on the inverter, enabling it to handle closer to its rated VA as Watts. It will never be perfect. Nothing ever is.
  • BB.BB. Super Moderators, Administrators Posts: 31,171 admin
    Re: Whole house active power factoring solutions?

    Also remember that Capacitors only work on "Inductive Loads" (i.e., AC induction motors) to reduce current (improve power factor).

    Battery charger, computer power supplies, CFL/LED bulbs, many electronics have "non-linear" (non sine wave current profiles)--And Capacitors do not improve power factor for those times of loads.

    If you are going to spend the money--Look for PF Correct power supplies.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • NorthGuyNorthGuy Solar Expert Posts: 1,925 ✭✭
    Re: Whole house active power factoring solutions?

    I wouldn't worry about power factor. I didn't see any difference in my system performance between inductive (pf 0.7) and comparable resistive (pf 0.97) loads.
  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Whole house active power factoring solutions?

    Thank you for the information.

    I was aware of those scams on the "passive" PF correcting things and knew myself they would not help, which was why I was thinking along the lines of the "active" ones that are used in commercial applications; which I know are generally more expensive. I guess I was hoping there was a smaller scaled one that was less expensive.

    I was under the impression that ANY inductive load could be power factor corrected (via "active" correction) even if it was not (for example) a motor which has a fixed PFC value. Is this not the case?
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • BB.BB. Super Moderators, Administrators Posts: 31,171 admin
    Re: Whole house active power factoring solutions?

    Yes, you can compensate an Induction Motor with an appropriate sized capacitor. The typical industrial PFC is usually a capacitor and relay to switch it in and out as needed (lightly loaded induction motors generally have worse Power Factor).

    You do have to worry about too large of capacitor (correctly to 1.0 or even positive leading current PF)... The capacitor and motor can work together and make a nice high voltage generator as the motor spins down (momentum) and cause other issues.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Whole house active power factoring solutions?
    BB. wrote: »
    The capacitor and motor can work together and make a nice high voltage generator as the motor spins down (momentum) and cause other issues.

    -Bill

    I've run into this with one of the freezers I rewired for Cap start. Works perfectly on start, but rapidly pulses/stutters one of the AC relays as it's spooling down after the thermostat cuts power.
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Whole house active power factoring solutions?

    Don't buy into all that PF Hype, in real life it's not so great. Here is what on a test I did on a $300 .90 + PF charger that was touted as something great. It wasn't even close. If anyone has a measure better than amps in / amps out, let me know what it is.


    Meanwell .90 PF ++

    Input 7.39 amps ac @ 120V

    Output 51.4 amps dc @12.7 v

    51.4/7.39 = 6.95 DC amp's for every 1 amp AC of input



    IOTA (.67 PF ?? )

    Input 8.64 amps ac @ 120V

    Output 75.9 amps dc @12.7 v

    75.9/8.64 = 8.78 DC amp's for every 1 amp AC of input
  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Whole house active power factoring solutions?

    My primary concern for it (with the charger mostly) was because with a low PF it is drawing more from the generator than needed. Hoping to correct its PF would allow it to only draw the REAL power from the generator rather than the excess that is wasted.

    It's not so much of a fuel consumption issue as it is a LOAD issuse in that running (for example) the charger and a single A/C, both of which have horrible PF's can overload a 2000w generator even though REAL power consumed by them should be under 2000W.

    I know I can fix the A/C via adding the proper running caps to the motor, but the charger varies the draw based on how much it needs to output so since that will very, I would need an active solution that switches in certain caps based on the draw. I have seen large scale active switching solutions but as we all know, very expensive. Was hoping someoen knew of a small scale version of one.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Whole house active power factoring solutions?

    Your talking about two items that both have huge starting loads, running not so much. The charger has to load the caps and the A/C starting load. The A/C you can help, depending on how much your willing to spend. Most would say, to spend $400 on a $100 A/C, forget it. They'll buy a $20 kicker and that doesn't work, thats the end of it. From what I found with a charger your wasting your money, buy a smaller one.
  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Whole house active power factoring solutions?
    Your talking about two items that both have huge starting loads, running not so much. The charger has to load the caps and the A/C starting load. The A/C you can help, depending on how much your willing to spend. Most would say, to spend $400 on a $100 A/C, forget it. They'll buy a $20 kicker and that doesn't work, thats the end of it. From what I found with a charger your wasting your money, buy a smaller one.

    Who makes a good external 24v charger in the 40ish AMP range that has active PFC built in?
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Whole house active power factoring solutions?
    jcheil wrote: »
    Who makes a good external 24v charger in the 40ish AMP range that has active PFC built in?
    You have to tell me what " active PFC " does ?? Does it take in less current to give you more output ?? You do realize that a 40 amp @ 24 V will pull easy with a starting load of over 25 amps + That size charger is in the $500-$900 range, I usually will get a old TR or DR 1524 Inverter and use the 35 amp charger on them. They are cheap these days or go the the Inverter Service Center and get one Free. A Inverter Charger is smart enough to Ramp the load a must on a small generator.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Whole house active power factoring solutions?

    Obsessing on an irrelevant problem.

    Blackcherry04 tested the supposedly "poor PF" charger built in to the Outback and found it was just as good as a supposedly "PF corrected" Iota.

    Cynic that I am, I suspect the it's little more than marketing hype and a capacitor solder on to the input. Trying to correct power factor on a varying induction load such as a transformer for a charger is difficult and not worth the effort.

    As I said before it only really affects the rated capacity of the inverter, not the power drawn from the batteries. The PF on most of these items (save motors and some poor-quality CFL's) is only off by a little and not worth bothering with. It is highly doubtful that investing in such correction, even if it did work, would be worth the money.

    But hey, don't listen to me; it's not my money you're spending.
  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Whole house active power factoring solutions?

    Thank you all.

    I guess in that case I shall leave it alone. I have just seen so many posts here about chargers and inverter/chargers and making sure that they are PFC that I thought it would be something worth investigating.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Whole house active power factoring solutions?
    jcheil wrote: »
    Thank you all.

    I guess in that case I shall leave it alone. I have just seen so many posts here about chargers and inverter/chargers and making sure that they are PFC that I thought it would be something worth investigating.
    It's a good discussion to have, personally I did put up $300 to test one and it didn't show me I got More, I got Less. There also was a weird issue, it was too sophisticated to give constant output, every time it sensed a load surge ( Inverter ) on the Battery Bank it would cut it's output and go into a fault. This was a Meanwell PB-1000.

    Added :

    The Outback GFX has proven to be the best charging source I ever tried, it has everything I ever wanted in a Inverter / Charger. It's rampy and it does not over shoot the set limit. It was not the best for amps in / amps out. The Magnum MM1212 with a 70 amp charger would go right up to 70 amps and then cut it's self back to the 30 amp limit that was set limit. It was totally worthless on a small generator. I am a field guy, all I can do is take the equipment and see how it works if it has a quirk, I look for a workaround. You'll see me with a RTS in a glass of Ice to get more Voltage if I need it, till I find the right resistance to make it work ....

    Xantrex is a perfect example, their Input Amp settings are 5, 15, 20, 25 & 30. Where in the heck is 10. Xantrex True Charge is 20,40,60 80 & 100 % output. How in the heck can you work with that.

    .
  • NorthGuyNorthGuy Solar Expert Posts: 1,925 ✭✭
    Re: Whole house active power factoring solutions?
    jcheil wrote: »
    My primary concern for it (with the charger mostly) was because with a low PF it is drawing more from the generator than needed.

    More of what?

    ...
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Whole house active power factoring solutions?
    NorthGuy wrote: »
    More of what?

    ...

    More power. As in the VA doesn't equal the W.
  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Re: Whole house active power factoring solutions?
    jcheil wrote: »
    My primary concern for it (with the charger mostly) was because with a low PF it is drawing more from the generator than needed. Hoping to correct its PF would allow it to only draw the REAL power from the generator rather than the excess that is wasted.

    It's not so much of a fuel consumption issue as it is a LOAD issuse in that running (for example) the charger and a single A/C, both of which have horrible PF's can overload a 2000w generator even though REAL power consumed by them should be under 2000W.

    A low PF load wastes very little real power. There are a lot more volts and amps sloshing around in the wiring, but this current is not being consumed (other than slightly increased resistive losses).

    For example, if you have a 1000 watt load with a low PF that draws 1500 VA, you will need a generator rated to handle 1500 watts. However, that generator will consume fuel as if it had a 1000 watt resistive load.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Re: Whole house active power factoring solutions?
    Blackcherry04 tested the supposedly "poor PF" charger built in to the Outback and found it was just as good as a supposedly "PF corrected" Iota.
    My recollection is that he tested the PF corrected Meanwell charger against the non PF corrected Iota.

    I also recall that Crewzer tested the PF of the Outback inverter/chargers and found they were quite good, as long as the charger is supplied with a pure sine wave.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Whole house active power factoring solutions?
    vtmaps wrote: »
    My recollection is that he tested the PF corrected Meanwell charger against the non PF corrected Iota.

    I also recall that Crewzer tested the PF of the Outback inverter/chargers and found they were quite good, as long as the charger is supplied with a pure sine wave.

    --vtMaps
    How would you test the theory that a low PF charger consumes less power from a generator ?? All I could test is amps in vs amps out.
  • bmetbmet Solar Expert Posts: 630 ✭✭
    Re: Whole house active power factoring solutions?

    Meanwell ?

    Meanwell is a Chines advertising ploy that has been translated, "Awww, so sorry. We Meant Well. Thanks for the money".

    I can't recall all of the Chinese products that slur an Idiom into a piece of crap, but several of them are in the solar RE market. If their product name sounds like an old saying (or a catch-phrase), don't waste your time.
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Whole house active power factoring solutions?
    bmet wrote: »
    Meanwell ?

    Meanwell is a Chines advertising ploy that has been translated, "Awww, so sorry. We Meant Well. Thanks for the money".

    I can't recall all of the Chinese products that slur an Idiom into a piece of crap, but several of them are in the solar RE market. If their product name sounds like an old saying (or a catch-phrase), don't waste your time.
    I hear you .....lol. All I know is for every 1 amp I put in, I get 20% less out, it's something I can see on a DC Amp Meter.
  • NorthGuyNorthGuy Solar Expert Posts: 1,925 ✭✭
    Re: Whole house active power factoring solutions?
    More power. As in the VA doesn't equal the W.

    V being the same, more VA means more A. What's the reason behind worrying about more A? Overhearing of windings?
  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Re: Whole house active power factoring solutions?
    How would you test the theory that a low PF charger consumes less power from a generator ?? All I could test is amps in vs amps out.

    I can think of at least two ways:

    Try running a high and low PF charger through a kill-a-watt and see what the kwh load is on an hour of bulk charging.... better yet, measure gasoline consumption of your generator after an hour of powering each of the chargers.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Whole house active power factoring solutions?
    vtmaps wrote: »
    I can think of at least two ways:

    Try running a high and low PF charger through a kill-a-watt and see what the kwh load is on an hour of bulk charging.... better yet, measure gasoline consumption of your generator after an hour of powering each of the chargers.

    --vtMaps
    Why would the Kill a Watt show something different than the Amp Meter ?? Isn't that just a different total what I already know ??
  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Re: Whole house active power factoring solutions?
    Why would the Kill a Watt show something different than the Amp Meter ?? Isn't that just a different total what I already know ??

    Kill-a-watt will tell you watts and VA. knowing the V and the A doesn't necessarily tell you the watts. In an AC circuit the A and the V are not necessarily in phase, so multiplying V by A does not necessarily give watts.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • BB.BB. Super Moderators, Administrators Posts: 31,171 admin
    Re: Whole house active power factoring solutions?
    Why would the Kill a Watt show something different than the Amp Meter ?? Isn't that just a different total what I already know ??
    Not really.

    We use the Kill-a-Watt meter a lot because it is cheap and gives repeatable numbers. But not necessarily the "correct" numbers.

    My guess is that the Kill-a-Watt meter measures "peak values" (the peak of the sine wave) values for voltage and current. And simply use 1/srt(2) to convert to RMS. For pure sine waves that 1/srt(2) conversion is mathematically correct. That is what "cheap" digital mutli meters do too.

    For different wave forms, the conversion number is different (square waves, modified square wave, triangle wave, impulse, etc.)... For measuring "arbitrary" wave forms, you need a DSP based Digital Meter (or analog meter designed to measure RMS energy) that can sample the wave form and "do the math" to convert to RMS (root mean square) wave forms.

    Attachment not found.

    Tyically, that is $300+ Fluke meter with ~50k samples per second to properly calculate the True RMS measurements (as I recall).

    How accurate are K-a-Watt meters on MSW and non-PFC power supplies--Probably not that accurate. However for resistive loads and inductive loads--They should be relatively accurate (within 5%-10%?).

    There have been a couple people that have measured Iota power supplies and came up with PF~0.65 and Efficiency of ~0.80 -- with 0.52 overall VA eff (confirmed by Iota) ... And the Meanwell with ~-0.82 VA efficiency overall.

    I know that BC04 came up with much different numbers for the Iota:
    Meanwell .90 PF ++
    Input 7.39 amps ac @ 120V
    Output 51.4 amps dc @12.7 v
    51.4/7.39 = 6.95 DC amp's for every 1 amp AC of input

    IOTA (.67 PF ?? )
    Input 8.64 amps ac @ 120V
    Output 75.9 amps dc @12.7 v
    75.9/8.64 = 8.78 DC amp's for every 1 amp AC of input
    • MW=(51.4a*12.7)/(7.39*120v)= 0.73 "VA efficiency"
    • Io=(75.9a*12.7v)/(8.64a*120v)= 0.93 "VA efficiency"

    We have been around this question before. I believe that BC04 did the measurements to the best accuracy he could with the meters he had available. And since I have not done the measurements (and do not have the devices or the equipment to make such measurements)--I will say quiet--Other to say that I do like PFC power supplies (and designed many larger computers systems with PFC as a requirement) and found it to be useful.

    But I also do know that measuring AC (and pulsed DC) current/arbitrary wave forms is difficult to get truly accurate. There are reasons it costs $10,000 for calibrated test gear that is capable of making these measurements with better than 5% accuracy--And even then, different mfg. do not always agree when measured in different labs. :cry:

    If you use the numbers from the first supply Iota 27 volt @ 15 amp power supply (PDF file):
    • (27 volts * 15 amps) / (7.3 amps * 108 VAC) = 0.51 "VA Efficiency"

    From the PDF, >80% efficiency, backing out the Power Factor would appear to be:
    • 0.51 VA eff / 0.80 power eff = 0.64 PF (estimate)

    Why are BC04's measurements different? I do not know. I would suspect the meters did not accurately reflect the RMS current for the Iota Power supply (that "spiky" current wave form). But is it purely a guess.

    Again, not trying to start an argument--Just following the discussion. I am confused:confused:.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Whole house active power factoring solutions?

    Kill-A-Watt: $30
    Fluke: $300

    Hmm. Which do you think is more accurate? :D

    Much of this is a tempest in a teapot anyway, as you have to work with what you've got. Odds of that being a pure sine wave of 120 Volts RMS at exactly 60 Hz with zero THD and devices with a PF of 1.0 - oh, about a billion to one.
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Whole house active power factoring solutions?

    All I have is two pictures and was able to read two Amp meters one in AC and one out DC. Feel free to figure them out. You tell me what amps in and amps out means. All a Kill a Watt is going to do is totalize something I already know, what will that tell us about DC amps with out a shunt and some other total, it is a battery charger. Maybe amps aren't really amps these days.

    Meanwell PB-1000

    Attachment not found.


    IOTA DLS_75

    Attachment not found.
  • NorthGuyNorthGuy Solar Expert Posts: 1,925 ✭✭
    Re: Whole house active power factoring solutions?

    KaW measures watts. Fluke doesn't. KaW error is probably within 100W, often within 50W.
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