Hi all,
Looking for a better workaround for this issue. I'll try to explain the setup briefly.
Setup:
I have an EQ4800 plus H3-15 3-phase inverter. There are three "backup" circuits configured, so if I get a blackout, those 3 circuits are powered from the battery.
The inverter/battery is fed from my powerboard via a 25A 3-phase CB. There is another 25A 3-phase CB in the board for power going back out of the inverter/battery.
I have a free power window from 11am-2pm each day, and have the mode scheduler set to force-charge the battery for that period at 15kW. It regularly charges at between 14 and 14.9kW.
Issue:
If I'm not drawing any particularly big loads during that period, then there is no problem.
BUT, occasionally, if I draw a large load on one of the backup circuits when the battery is charging at ~14.9kW, then I trip the battery input CB. This doesn't always happen. If the load ramps up, the inverter seems to compensate, and the charge rate drops to say 13kW while a 2kW load has been applied. But if the load starts suddenly (eg I turn on a kettle), then the CB trips.
I'm pretty sure I know why this is happening: Battery charge load + backup circuit load is exceeding 25A on one of the phases, and that causes the CB to trip.
Solutions?
My current workaround is to manually limit the battery charge amps on the inverter panel, dropping the force charge rate to around 10kW. But that's not ideal, because if the SoC has dropped below about 25% by 11am, then it's not enough to fully charge the battery by 2pm.
What I'm looking for is a setting that will let the battery charge at the full 15kW when it can, but automatically adjust the charge rate quickly to allow for loads that start on the backup circuits. Essentially a setting to hard-limit the total throughput of the inverter to 15kW counting both the backup loads and the battery charge.
Alternatively, would it be OK to upgrade the CB to a 32A? The wiring is fine for that (4mm2), and I presume the inverter will limit itself to 15kW as required, it's just doing so a bit slowly at present, causing the CB to trip before it ramps. I'm presuming it shouldn't actually go above 25A for more than a brief period given its capacity, but it's taking too long to react currently.
I have access to the Installer level cloud interface.