Seems that is the max export output, which is per phase.
It can be limited by settings, which are set to the DNSP's requirements.
Eg. I think you are Energex ?
Google . . .
In Brisbane, standard Energex export limits are 5kW for single-phase and 15kW (5kW per phase) for three-phase connections, but these can be increased with an export-limited inverter or by joining Energex's Dynamic Connections program. The Dynamic Connections program allows for more flexible, higher export limits, sometimes up to 10kW per phase, but it can be automatically reduced during grid congestion or emergencies.
This is like our flexible exports with SAPN in SA, and I guess your solar people had you connected with your 'dynamic connections' progamme up there ?