Liebert S600 User Manual page 36

You can manually set the 'Master' and 'Slave' through the LCD.
The UPS which is set to LBS master can send synchronization signal to LBS salve according to the own inverter
voltage phase. After the slave receives the synchronization signal sent by the master, the slave will adjust its
inverter voltage phase to realize the inverter voltage phase is synchronized with the master.
Through the above to realize the inverter voltage phase synchronization of two sets of UPS system and realize the
reliable transfer between the two sets of UPS output voltage and STS, then provide the reliable uninterrupted power
supply to the load.
Vertiv|Liebert® S600 10kVA ~ 20kVA UPS | User Manual 36