A client has a Sunsynk inverter solar installation, prepaid meter shows 7-10 kWh consumption in a 24 hour period. however, the app shows no import, as there is sufficient solar production and batteries. the CT is mounted on top of the main breaker ( live ).
We haven’t been able to find this power draw anywhere in the main db.
Any suggestions ?
Can you measure this current?
Are you sure that it’s not current fed into the grid (given that the new meters bill on both)
If export is limited, you will never get down to 0. The problem is that the Sunsynk will measure the average over a period and adjust for that, but the prepaid meter will measure very fast and accurately and count everything in both directions.
So imagine you have something that switches on and off quickly, say a 100W gizmo that is on for 100ms, off for 100ms. The sunsynk will take the average over a period (say 600ms) and measure 50W and then generate 50W to offset that usage. The prepaid meter will see 50W being exported when the gizmo is off, and 50W being imported when the gizmo is on, and add them both to the running total.
It becomes even more complicated when the gizmo switches at a period greater than the Sunsynk is averaging over.
Unfortunately the result is that for most households, you will always have some import when connected to the grid (and not exporting).
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