question

Please check: Does this happen only if the battery is full or does it also happen if bat is below 100% SOC?

Are you sure that is all you have connected? You say "No 3 phase loads connected to this supply". Does that mean there are in general 3 phase loads present? Some circular/buzz saw maybe?

Or more general: What are the loads connected to the system? You know the AC output can become an Input if there is some energy surplus and if in this case the battery is full so that energy cannot be routed to it, even with a forbidden feed in, feed in still happens.

For up to 30 minutes makes me think you have something connected on AC out that can become a generator for extended periods of time. (I have here a microinverter connected to the AC out of a Quattro and actually even though the Quattro is forbidden to feed-in, it still does so in extreme situations).

The wiring in the house is set up such that the electric cooker is on one phase, the electric water geysers are on the second phase and the lights and sockets are on the third phase where the inverter is connected. Therefore there are no 3 phase loads connected to the system.

From the above graphs it can be seeen that the SOC of the batteries is never 100% when the ACInput power goes negative. When the AC input goes negative, the inverter displays PASSTHRU on the CCGX.

Please advie if there is any additional information that i can get for you?

Do you have an energy meter connected to this system?

Hi Murray. There are no energy meters on this system.

Hi Barry,

Have had the same issue here in Zim, on and ezy 5 -

eventually added an ess assistant - set grid support to 300 watt - this seemed to have stopped it.