Liebert 300 series Installation, Operaton & Maintenance Manual page 52

3.9.2 Operator Response
1. Press Alarm Silence
audible alarm. (It will sound again at the
2. Verify a power failure has occurred. In
addition to indicators and alarms on the
UPS, there should be other indications, such
as the room lights being off.
While the battery is supporting the load, you
3.
may reduce the load to extend the battery
time. (Remember that the calculations for
battery time remaining may take a few
minutes.)
NOTE
Determine time required toperform an
orderly shutdown
of
Begin shutdown so it will be completed
while the battery is still supporting the
load.
When battery time remaining has
decreased to 5 minutes, reducing the load
will extend
not battery
3.9.3 As Battery Time Approaches
Zero
1. If input power is restored while the UPS
battery is supporting the load, the UPS will
automatically begin conditioning input
power. This conditioned power supports the
load as it simultaneously recharges the
battery.
2. If equipment supported by the UPS is
drawing power from the battery as time
approaches zero, the UPS continues to
supply power to that load until the battely
reaches a pre-set voltage level (zero time).
To protect the battery from damage, the
UPS then shuts itself off and no longer
supplies power to the load.
If the control system shuts down the UPS at
3.
Auto Restart is
zero time and
UPS remains off even when input power is
restored. To restore power to the load. turn
Rotary Switch counterclockwise to Position
1. The critical bus will be energized as
pad to cancel the
the critical load.
time.
disabled, the
soon as the Rotary Switch is in
Position 3. Perform start-up (Section 3.6
from Position 1. Manually reset
Start-up)
and close the battery circuit breaker(s),
when supplied, to reconnect the battery.
CAUTION
Turning the Rotary Switch
counterclockwise from Position 4 to
Position 3 will energize the critical bus.
Make sure critical load equipment is
ready for power before turning Rotary
Switch.
CAUTION
Recharge batteries as soon as possible
after discharge. Batteries should be
recharged within 24 hours to avoid
sulphation and to preserve battery life.
4. If the control system shuts down the UPS at
zero time and Auto
UPS will restart the load 10 seconds after
input power is restored (refer to
3.5.2 System Configuration).
reset and close the battery circuit
breaker(s), when supplied, to reconnect the
battery.
3.10 RESPONSE TO A UPS FAILURE
3.10.1 UPS Response
1. The Static Transfer Switch instantly
transfers the load to the Static Bypass Line
without interruption of power.
An audible alarm will sound.
2.
3. The following message will
on Static
Check Messages
4. An Advisory Display LED may illuminate,
prompting movement of the rotary switch.
Restart is the
enabled,
Section
Manually
appear: