American Power Conversion SYMSTRF Power Supply User Manual


 
On-Battery Operating Mode
When in the on-battery mode, the Power Array draws DC
power from the battery source, converts it to conditioned AC
power that is then delivered to the load equipment.
Symmetra
TM
typically enters this mode in the event of a utility
power failure. It will also operate in the on-battery mode
during a user initiated battery self test.
On-battery operation is limited in duration and is dependent
upon the number of battery modules, their state of charge,
and the size of the load. Symmetra
TM
will remain in the on-
battery state until either the incoming utility power is restored,
or the batteries are depleted. See figure I-5 for a diagram of the
power flow when the system is in the on-battery mode.
Fig I-5 On-Battery Operating Mode
Bypass Operating Mode
When the Symmetra
TM
is in the bypass operating mode, the
system is bypassed, and utility power is delivered directly to
the load. Symmetra
TM
is equipped with an automatic bypass
function to allow the system to automatically go into bypass
mode, and a manual maintenance bypass switch to allow a
user to manually bypass the system. Either can be used to
place the Power Array into bypass operating mode.
The Symmetra
TM
will automatically transfer to the bypass
operating mode when AC utility power is present, but the load
cannot be powered by the inverter. Events which may cause
this include overloads, or failed non-redundant power mod-
ules. The Symmetra
TM
will automatically return to the on-line
mode when the triggering event clears. Figure I-6 illustrates
the power flow when the system is in the bypass mode.
Fig I-6 Bypass Operating Mode
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