SMA AUTOMATIC SWITCH BOX M-20 - Manual (Page 32)

5 Electrical Connection SMA Solar Technology AG
32 AS-BOX-M_L-IA-IEN110320 Installation Guide
5.4 Activating the phase coupling for 1-phase Backup System
In case of a grid failure, the Automatic Switch Box M can supply loads which are not connected to
the Backup-Phase L1. In the event of a grid failure, you can choose whether the Automatic Switch Box
connects all 3 phases or just 2 phases. As soon as the power distribution grid returns, the
Automatic Switch Box disconnects the connected phases.
• Switch on switch-disconnector "Q9" and "Q10" for coupling all 3 phases in the case of a grid
failure.
• Switch on switch-disconnector "Q9" for coupling L1 and L2 in case of a grid failure.
• Switch on switch-disconnector "Q10" for coupling L1 and L3 in case of a grid failure.
• Attach warning sticker "phase coupling" in the distribution when phase coupling is activated.
• Check if the parameter "224.01 SilentEna" of the Sunny Backup is set to Disable when phase
coupling is activated. If the parameter "224.01 SilentEna" is set to Enable, set the parameter on
Disable. This is to deactivate the "Silent Mode" of the Sunny Backup and to make the phase
coupling of the Automatic Switch Box possible.
Switch-over times to Backup operation
The switch-over times for the loads on L2 and L3 are longer than for the loads on the Backup-
phase L1. The switch-over times just take seconds.
Capacity overload of Sunny Backup during phase coupling
• Only activate phase couplings for phases whose power does not exceed the maximum
power of the Sunny Backup (see section 10 "Technical data", Page 52).
Destruction of 3-phase loads during phase coupling.
• During phase coupling only connect 1-phase loads to the Automatic Switch Box.