Clarification on Generator input

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  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Clarification on Generator input

    Update: Meters arrived today, should have them installed this weekend sometime and then I am going to run the tests again and post the results.
    Hope it takes some of the mystery out of everything.
    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
  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Clarification on Generator input

    OK, sorry for the LONG delay but real life got in the way.

    Finally hooked up the meters (they are quite awesome BTW), and everything jives.

    The power factor was what was causing the differences in the calculations of what we thought should be and what really was.
    Using the clamp meter just wasn't an accurate measurement.

    I confirmed via the new meters that the Honda generator IS showing true Va on it's display which matches perfectly to the meters readings. Since these meters take into consideration the COS (they even shows that value), they are a great tool and I recommend them, especially for the minimal cost. I added two for the output legs of my inverters also. it's interesting to see the PF that my loads are consuming.

    And when I take the WATTS (not Va) shown on the additional meters divide by amps, I get the exact AAC setting shown on the mate3/Inverters settings so everything is much clearer now. Looks like for my dual setup with the Honda EU7000, 18AAc for each inverter on the GEN INPUT is the max you want to go to keep the generator at the 5500-ish max-continuous VA rating. Although I am still wondering is 18AAC would allow me to get the FULL charging POTENTIAL out of the inverter (assuming there were NO loads)?

    ...and BTW - it appears the outback inverter/charger IS pretty close to PF corrected. When on generator the other day the PF showed in the upper .95's
    Now, I was also running loads so I am not sure if there was a leading PF "compensating" or whatever. When I get some time I will open the breaker feeding my loads and just run the charger and see what the PF is. I am thinking the PF might change slightly based on how much current it is producing right or perhaps they have some way of auto-correcting it?

    Anyways, thanks for all the help and I hope this helps someone else in the future!
    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: 32,609 admin
    Re: Clarification on Generator input

    I believe you have VA and Watts reversed in the above post...

    Watts = VA * PF = VA * Cosine (current vs voltage phase angle)

    And PF / Cosine ranges from 0.0 to 1.0 ... So VA>= Watts

    Watt/Volts will be equal to or less than VA/V ...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • CDN_VTCDN_VT Solar Expert Posts: 492 ✭✭✭
    Re: Clarification on Generator input

    Like to see how you wired in this meter. can't figure wiring diag on the back .
    http://www.ebay.com/itm/3in1-Voltage-Current-Power-Panel-Meter-LED-Digital-Gauge-AC-100A-80-300V-Cu3-/121440907526?pt=LH_DefaultDomain_0&hash=item1c46713106

    VT

    Sorry I see it today ..
    Sometimes you can't see for looking

    VT
  • vtmapsvtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    Re: Clarification on Generator input
    jcheil wrote: »
    ...and BTW - it appears the outback inverter/charger IS pretty close to PF corrected. When on generator the other day the PF showed in the upper .95's
    Now, I was also running loads so I am not sure if there was a leading PF "compensating" or whatever. When I get some time I will open the breaker feeding my loads and just run the charger and see what the PF is. I am thinking the PF might change slightly based on how much current it is producing right or perhaps they have some way of auto-correcting it?
    Forum member "Crewzer" wrote about Outback power factor. He found it was very good during bulk charging, but declined a bit during absorb. Also, he found it depended on the quality of the sine wave from the generator... too much distortion from the generator lowered the PF.
    jcheil wrote: »
    I confirmed via the new meters that the Honda generator IS showing true Va on it's display which matches perfectly to the meters readings. Since these meters take into consideration the COS (they even shows that value)
    Some of the worst power factor problems can NOT be considered leading or lagging, and Cosine doesn't mean anything. These are loads that switch or clip the sine wave power they are consuming. For example, some switching power supplies only draw power from the peaks of the sine wave power from your generator. These types of loads may be considerable in some systems. Switching power supplies are very efficient and becoming very common for DC lighting and for powering electronics. My point is that meters such as yours, or a Kill-a-watt, or the meter in the Honda, do not give the full power factor story of the load they are measuring.

    The important question (and I don't know the answer) is "How does my inverter generator (or my inverter) behave when it is powering a substantial switching or clipping load?".

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • BB.BB. Super Moderators, Administrators Posts: 32,609 admin
    Re: Clarification on Generator input

    This is a picture of what vtmaps was talking about--Poor power factor due to waveform distortion:

    Attachment not found.

    The voltage sine wave and short current peaks near sine wave voltage peak.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Clarification on Generator input
    CDN_VT wrote: »
    Like to see how you wired in this meter. can't figure wiring diag on the back .
    http://www.ebay.com/itm/3in1-Voltage-Current-Power-Panel-Meter-LED-Digital-Gauge-AC-100A-80-300V-Cu3-/121440907526?pt=LH_DefaultDomain_0&hash=item1c46713106

    VT

    Sorry I see it today ..
    Sometimes you can't see for looking

    VT

    I went with the meter in the other link I posted because that one said it came with the CT for sure (it was like $1 more).
    But there was a diagram on the back of them and the link you posted above has a picture of the diagram also on the ebay pictures.

    But basically just 4 connections. 2 for the AC (hot/neutral) and 2 for the leads of the CT.
    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
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