[RE-wrenches] active vs apparent power readings with solar

[Darryl Thayer]

This power factor is impossible,  can he measure the apparent power then
the real power separately devide the real by apparent to get power factor.
I guess he has connections wrong, wrong leg of split phase.  If the
inverter is off, then possible, do you measure current off the inverter and
DC into the inverter?

On Thu, Apr 27, 2023, 4:11 PM August Goers via RE-wrenches <
re-wrenches at lists.re-wrenches.org> wrote:

> Hi Wrenches,
>
> We have a residential site with grid tied solar where there is an
> electrician involved who has gotten into taking site readings and thinks
> there is a power factor problem. My gut on it is that there is some sort of
> measurement reading error, and that the power factor should be around 1.
>
> The electrician is using a Fluke 3540FC power monitor and has provided a
> spreadsheet comparing active power to apparent power and calculating power
> factor. See below (you might have to open the image and zoom in to read
> it). This measurement was taken with a PV system running, presumably
> sending some power back to the grid.  Note that the phase B active power
> measurement is negative (PV exporting to grid) and that the apparent power
> is positive. This nets in a power factor that is crazy low of 0.05.
>
> Does anyone have experience about whether a meter like this can properly
> measure these readings - maybe there is a setting error or it can't deal
> with negative readings?
>
> [image: image.png]
>
> Best,
>
> August
> Luminalt
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