Liebert AC4 User Manual

7.8.3 Specify Failed Standby Response
The Liebert AC4’s Failed Standby feature determines what happens when an operating device fails and a
standby device then becomes an operating unit. A subsequent alarm in the newly operating unit
(previously the standby device) results in either restarting the previously operating device that was
alarmed or not. This feature specifies whether each device remains in its current state or returns to its
previous state of operation.
When this feature is activated (Y), each device returns to its previous state, as Table 7.8 below shows: the
newly enabled Standby device is disabled and the previously operating device is returned to Operating
mode. The default setting is N (deactivated), meaning that each device remains in its current state: the
Standby device remains enabled and the previously operating unit remains disabled.
Failed Standby
Setting
Previous Standby Device
(alarm after being enabled)
Previously Operating
Device
Activated (Y) Disabled Returned to Operating mode
Deactivated (N) Remains enabled Remains disabled
Table 7.8
Failed Standby response
To change the Failed Standby settings:
• From the Setup System Operation Menu, use the arrows to
choose Failed Standby, then press Enter.
• In the Change Failed Standby screen, press use the arrows to
choose Y to activate or N to deactivate the feature.
• Press Enter.
7.8.4 Specify Hold Delay Time
After an output changes state, the hold
delay timer directs the Liebert AC4 to ignore
all inputs in the same zone for the specified
time.
This delay is the amount of time that must
elapse before the Liebert AC4 acknowledges
a change of state in any input. The default is
10minutes (displayed as 10 MIN : 00 SEC).
The time delay applies only when a
monitored output device changes from its
normal state—for example, the Liebert AC4
detects a closed contact that is defined as
Normally Open.
When the output device returns to its normal state, the Liebert AC4 acknowledges any input change of
state immediately.
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Liebert AC4 Specifications

General

Brand	Liebert
Model	AC4
Category	Control Unit
Language	English