Connect System S to the backup phase
The Backup phase is the line conductor that is fed with electric current by the Sunny Backup system in the event of an outage of the power distribution grid. Electrical devices that are required in the event of a power outage must therefore be connected to this phase.
When using a System M or L, all three phases can continue to be fed in the event of a power outage: When using a System M, the phases are connected automatically so that all single-phase loads can continue to be fed on all three phases. All three-phase loads must be disconnected from the voltage supply at this point, as the Backup System M cannot provide a three-phase current.
The System L provides a three-phase power distribution grid so that three-phase loads can continue to be supplied.