Eaton 9395 Plus 1, Инструкция по установке и эксплуатации

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UNDERSTANDING UPS OPERATION
Eaton 9395 Plus 1 UPS (225–275 kVA) Installation and Operation Manual
S
164201710 Rev 2
www.eaton.com\powerquality 6-4
If commercial power voltage or frequency disturbances are detected, the system
forward transfers to Battery mode for minor disturbances and then to
double-conversion mode for more severe disturbances. During a complete power
outage, the transfer takes place within 2 ms to ensure loads being fed by the system
output are not interrupted. All forward transfers transfer to Battery mode before
returning to double-conversion mode.
In High Alert mode the unit transfers from ESS mode to double-conversion mode or if
in double-conversion mode remains in double-conversion mode for a default time
period of one hour (customer configurable). At the completion of the time period, the
unit defaults back to ESS mode. If the High Alert command is received during the
time period, the timer will be restarted.
ESS mode is a normal operating mode, and not an alarm condition. While the UPS is
in this mode, the Online light on the front display will illuminate.
6.2.4 Variable Module Management System
NOTE
VMMS and ESS modes are mutually exclusive. If VMMS mode is enabled, ESS mode is disabled.
In VMMS mode, the UPS operates as a traditional double-conversion UPS. However,
the UPS will selectively shift the load to fewer UPMs based on the required load in
order to force the remaining UPMs to carry a higher load. The efficiency rating for
each UPM is highest when loads are greater than 50% of the system rating.
Therefore, with multiple UPMs, a UPS can achieve higher efficiencies for lighter
loads.
When a UPM is placed into VMMS mode, the UPM will stop gating the inverter and
rectifier and keep the output contactor closed in order to maintain voltage match and
phase lock to the critical bus. In this mode the UPS actively monitors the critical bus,
keeping the UPM input contactors closed in order to keep the DC link primed (through
the rectifier diodes) and also to allow the UPM to immediately return to active mode
in the event of a disturbance or load step on the critical bus.
VMMS limits the maximum power available from a UPM when in VMMS mode. The
default setting is 80% of the UPM full power rating. If the limit is exceeded, additional
UPMs take on the increased load. The VMMS redundancy setting sets the number of
redundant UPMs that the customer requires. Both the VMMS UPM load limit and
UPM redundancy are customer configurable.
In High Alert mode, the UPS defaults to double-conversion Online mode and all UPMs
go active for one hour (customer configurable). At the completion of the hour, the
UPS defaults back to VMMS mode. If the High Alert command is received during the
one hour, the one hour timer will be restarted.
6.2.5 Bypass Mode
The UPS automatically switches to Bypass mode if it detects an overload, load fault,
or internal failure. The UPS can also be transfered from Online mode to Bypass mode
manually. The bypass source supplies the commercial AC power to the load directly.
Figure 6‐3 shows the path of electrical power through the UPS system when
operating in Bypass mode.
C A U T I O N
The critical load is not protected from voltage or frequency fluctuations or power outages while the UPS is in
Bypass mode.