So i have just had a Solar Battery installed and want to check a few things.
Ive noticed that when the battery is discharging, my Consumption outpput was in Negative Value, which im assuming will no longer give me correct overal house consumption readings?
Do i need to reconfigure my clamps so now i have 3 for the battery? (3phase setup)
Or does my output calculations need to be modified?
For what its worth, these my current outputs:
Just trying to get my head around it all
Cheers
Not really enough information to offer any advice. Some random thoughts:
If your consumption was always positive before the battery, seems like the battery might be exporting to the grid in order to get a negative Consumption.
It appears you have an integrator setup for Grid. That can be tricky with three-phase depending on how the utility calculates export. Consider whether the three phases are added for the net, or if each phase is independently measured as import/export.
A line drawing of your system would be helpful to understand what is going on.
Thanks for the response
Consumption was always positive prior. Now that nattery is in, i get a negative consumption when battery is discharging back to house
crude line diagram attached
Correct i have integrators setup
Sorry, do you mean on utility side or iotawatt side?
Well, both I think if they are to match up.
Couple more questions:
Is the battery inverter three-phase? (most of the units I’ve seen are single-phase).
How does the battery system know when to charge and discharge? I’m guessing it has its own CTs on the mains? Does it also have CTs on the solar inverter output?
Yes, battery inverter is 3 phase, inside the board they have intsalled a Chint DTSU666 meter, with CT’s on the mains and solar inverter cables - right next to mine actually! with a data cable from the chint meter to the battery inverter
As for the net metering, i believe all phases are added together at the meter
Sorry, been distracted for a few days. I’m interested in working through this issue. I took a look at the DTSU666 meter manual and it appears to only monitor one set of three lines. The diagrams show it on mains. Are you sure it has CTs on both the mains and solar lines? I’d be interested in how that is done. Perhaps they are wiring the Mains and PV CTs together such that they give the DTSU666 the net of solar and mains on each phase? The result of something like that may be used to inform the battery inverter how much power to add to the system.
What would be informative would be a plot of the sums of all three phases of the mains, solar and battery inverter. If you can gather that for an hour or so when a significant negative consumption is happening. Not saying this will tell all, but once isolated, it will be possible to produce detailed data that might be more revealing.
No apologies needed…
So i have confirmed that there are 6x CT’s coming out of the chint meter - 1 on each phase of the Solar leg and Grid leg. - Exactly where i have mine placed
Now, i have also just taken my lighting circuit and moved it the the Battery Inverter leg. These figures so far are mataching the Inverter numbers - Negative for battery discharging (and as its night, im going to assume positive figures will be Battery Charging)
Snapshot as of 8pm
Im going to guess, that with some calculated outputs i can get a more accurate “house consumption” and “Import/Export” figures
Inverter snapshot of approx same time
