Tod,
   You have inspired me to check my readings again, but it will be a be a couple of months before I get back to that inverter to check again. I will be installing an Ohio Semitronics on the inverter output. Given your data below, I will install another 3-phase Ohio Semitronics on the input. I can sample both at 1 Hz for a few weeks.

   Do you think that will be good enough? If not, what else do you suggest? I will post the results as soon as I have anything new to report.

--Mel

--- In small-wind-home@yahoogroups.com, "Tod Hanley" <thanley@...> wrote:
>
> Hi Mel-
>
> I am not sure where the errors in your efficiency measurements are.  We use
> a Fluke 41b for our measurements of power.
>
> We also have several Fluke 80i-110 current sensors, which are used to
> measure power with a 4 channel Tektronix scope with a power quality
> measurement chip.  Additionally we have 3 Ohio Semitronics power
> transducers.  All of these agree with each other pretty well.  In any case
> the efficiency numbers below are representative of the Powersync II
> inverter.  There is usually not more than a couple percent difference
> between inverter samples.  This one is a good one as usually the maximum
> efficiency is 93%.  The data are at steady state on the dyno.
>
>
> Palt [Wac]
>
> Pout [W]
>
> eff,inv
>
>
> 136
>
> 70
>
> 51%
>
>
> 420
>
> 330
>
> 79%
>
>
> 900
>
> 760
>
> 84%
>
>
> 1620
>
> 1410
>
> 87%
>
>
> 3500
>
> 3100
>
> 89%
>
>
> 4780
>
> 4300
>
> 90%
>
>
> 6600
>
> 6000
>
> 91%
>
>
> 8000
>
> 7300
>
> 91%
>
>
> 10200
>
> 9300
>
> 91%
>
>
> 12400
>
> 11200
>
> 90%
>
>
> 13000
>
> 12000
>
> 92%
>
>
> 13000
>
> 12000
>
> 92%
>
>
> 13000
>
> 12100
>
> 93%
>
>
> 13000
>
> 12100
>
> 93%
>
>
> 13000
>
> 12200
>
> 94%
>
>
> 12900
>
> 12200
>
> 95%
>
>
> 12600
>
> 12000
>
> 95%
>
>
> 
>
> Best
>
>              
>
> Tod Hanley
>
>
>
> [Non-text portions of this message have been removed]
>

Mel Tyree, BA PhD (Cantab.) LLD (h.c.) FRSC
Professor
Department of Renewable Resources
444 Earth Sciences Building
University of Alberta
Edmonton, AB, Canada
T6G 2E3
780-492-5597 (Office)
780-902-6771 (Home)
518-594-3815 (Mobile)