Solar Edge String Inverter De-rate in Off Grid/Back-Up Mode
If you are using a single aPower with the SE 11400, it is important to note that the inverter must be derated when in backup/off-grid mode. This can be achieved through two options provided by SolarEdge: RRCR "hard" stepped derating or the "Alternative Power Source" programmed/graded derating. Both of these options use the SE PRI (Power Reduction Interface).
To implement either of these options, you will need to procure a 240VAC voltage sensing relay, which you will have to integrate yourself. The voltage sensing input should be connected to grid voltage, anywhere between the line side of the aGate grid relay and the utility meter. The relay terminals should be connected to the SE PRI circuit.
It is important to select a derated nameplate value for the SE11400 so that off-grid/backup peak power is less than 6kW. This will prevent the single aPower from being overdriven, which can cause a full curtailment of PV.
If you are unsure about the right-sizing of the FranklinWH battery with the SE 11400, we recommend using two aPowers for a robust and capable solution. This is especially beneficial for customers with a lot of solar who would benefit from a two-aPower solution.
If you have any questions or need further assistance, please do not hesitate to contact us. We are always happy to help.