Emerson AC4 User Manual

Standby testing permits scheduling an automatic operational check of devices in Standby mode. 
When this feature is activated (ON), the Liebert AC4 tests all devices in Standby mode by putting 

each device in operating mode for a designated time. You may specify the time of day the testing 

begins, the duration of the test and the interval between tests. Standby testing is OFF (deactivated) 

by default. 
To change the standby testing settings:

• From the Setup System Operation Menu, use the arrows

↑↓

 to

 

choose Standby Testing, then press Enter ↵.

• In the Change Standby Testing screen, press Enter ↵ to edit 

Standby Testing, then use the arrows

↑↓

 to choose ON to activate 

or OFF to deactivate the standby testing feature. Press Enter ↵.

• Select the desired interval for how frequently the testing should 

occur in the Every 03 Days field. The default is 3 days; valid 

entries range from 0 to 99 days.

• For each digit, use the arrows

↑↓

 to choose a number from 0 to 

9, then press Enter ↵ to advance to the next digit. 

• When finished, press Enter ↵ to configure the time of day.

• Specify the time of day the test should begin in the At 00:00 field. 

The format is HH:MM for hours and minutes.

• Use the arrows

↑↓

 to

 

choose from available entries for hours 

(00-23), then press Enter ↵ to advance to minutes.

• Use the arrows

↑↓

 to select minutes (00-59).

• When finished, press Enter ↵ again.

• Specify the duration of the test in minutes—the length of time the standby units will be turned 

On—in the For 10 Min field. Use the arrows

↑↓

 to

 

choose a number from 0 to 59 minutes. The 

default is 10 minutes.

• When finished, press Enter ↵.

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 19 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.

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 ↵.

Activated (Y)

Disabled

Returned to Operating mode

Deactivated (N)

Remains enabled

Remains disabled

AUTO SEQUENCING OFF

FAILED STANDBY

N

↑↓=NEXT

↵

=SELECT

HOLD DELAY : 10:00
RESTART

: 00:06

EVERY 03 DAYS
AT 00:00 FOR 10 MIN

↑↓=NEXT

↵

=EDIT

AUTO SEQUENCING OFF
STANDBY TESTING OFF

↑↓=NEXT

↵

=SELECT

HOLD DELAY : 10:00
RESTART

: 00:06

↑↓=NEXT

↵

=END