Emerson 540VDC Power Supply User Manual


 
Auxiliary Backup AC Power Supply
150
APPENDIX F.0 AUXILIARY BACKUP AC POWER SUPPLY
Appendix F.1 Overview
The Liebert FS must be operated with a backup AC power supply to protect the unit’s mechanical
bearings if:
the external DC supply is lost,
the Liebert FS has developed a fault and
the configuration is two (and only two) flywheels arranged in a capacity configuration (i.e.: both
flywheels are required to carry full load). Not applicable to a redundant configuration.
If these two events occur simultaneously, the backup power supply will power the magnetic levitation
hardware to prevent the rotating group from running on the mechanical touchdown bearings.
This section details the function of the backup power supply and how it should be attached to the
Liebert FS. This is supplementary information—refer to appropriate sections of the user manual for
details on installation and operation.
Appendix F.2 Backup AC Power Supply Specification
Note: Connection to a 480VAC supply requires a 480 to 110 transformer, available from Liebert as an
option.
Appendix F.3 Recommended Backup Power Supply Configuration
Voltage: 110 to 230VAC, 500VA
Frequency: 50 to 60Hz
If the Liebert FS
is operating: Liebert recommends: For details, see:
In parallel
with batteries
Attaching the backup AC power supply to the output of the UPS. Figures 156 and 157
Without batteries
Feeding the backup AC supply from a separate, protected supply.
This may be the output of another UPS or a supply from a separate
feeder circuit.
Figures 158 and 159
DISCONTINUED
PRODUCT