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Appendix A. Specifications
Appendix A. Specifications
UPS Specifications
The Lenovo 6U Rack or Tower UPS, model 5594-8KX and model 5594-9KX, are single phase
UPS units.
The 6U Rack or Tower UPS, model 5594-8PX and model 5594-9PX, are three phase UPS
units with a wye connected load between 380V and 415V. The input is three phase, the output
is single phase.
Basic functionality
These UPS units are Online double conversion UPS units which can be manually switched to
High Efficiency mode in which these UPS units operate as Line interactive UPS units.
Online double conversion UPS units
Online UPS units are also referred to as VFI UPS units. VFI stands for Voltage and Frequency
Independent from mains supply. This type of UPS is referred to as an online or double
conversion UPS unit. UPS units of this design permanently route the input voltage via a
rectifier, that is the primary path for the power is always via the UPS inverter. During normal
operation the utility AC is never fed through to the protected load. This means that the
protected load is isolated from the actual input utility AC.
The generated DC is fed to both the UPS batteries and the inverter which in turn generates the
AC voltage for the output. This design ensures that there are no switching times in case of
utility power failure.
Switching times may occur when:
battery charger or a battery or inverter power path fails
•
unexpected and sudden change of load happens
•
the inverter suffers from an internal control glitch
•
In this UPS topology both the inverter and the battery charger continuously convert the input
power to DC and then back to AC. This leads to undesirable heat generation which as to be
dissipated. This results in reduced UPS operation efficiency.
This type of UPS is the best choice for very sensitive devices that are to be protected.
On-line UPS units will only pass the input power to their output in case it is switched to
bypass mode for maintenance purposes.
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6U Rack or Tower UPS RT8kVA and RT11kVA IUOMG
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