Operation
99
Liebert
®
APM
™
ECO Mode (Single-Module UPS System Only)
When ECO mode is selected, the Liebert APM switches inverter power from the UPS input to the
bypass input to save energy by improving UPS efficiency. In this mode, the bypass is the preferred
source. If the bypass voltage or frequency becomes outside preset limits, the UPS load is transferred
back to the inverter.
Battery Start Mode
The battery start option permits starting the Liebert APM with power supplied only by the batteries
(at charged condition).
Maintenance Mode
For maintenance or repair, the Liebert APM may be operated in maintenance mode. To place the
Liebert APM in maintenance mode, follow the instructions in
Normal Operation to Maintenance Bypass
Sleep Mode
Sleep mode allows equal run time on all power modules. The modules will put themselves offline for a
programmable period of 0-30 days. As a module goes offline, another module comes online. Each
module will rotate being online and offline.
Sleep Mode must be enabled by an Emerson Customer Engineer. A minimum of three power modules
are required for Sleep Mode to be activated. Once enabled, Sleep Mode requires no further action.
Any Power Modules that are not supporting the load will automatically enter sleep mode. During
sleep mode the system maintains one extra active power module in addition to those supporting the
load. Sleep mode can handle configurations with redundant power modules. When a power module is
in Sleep Mode, both LED indicators will turn Off. During extended periods of Sleep Mode, the
inactive power module is cycled through at regular intervals
Common Battery
Common Battery feature permits two Liebert APM’s to be connected to one battery cabinet. The
UPS’s may be separate systems or may be in a parallel system. LBS cannot be used while common
battery is enabled.
Paralleling Mode
This option is available only on 208V Input Parallel. This mode requires the buyout panelboard
paralleling gear. It can parallel the following:
• two APM’s
• 45kW or 90kW frames in any module capacity
• redundant
• can allow up to 180kW of load capacity
A sharing inductor is required for parallel units.
Output Voltage Adjustment
This feature allows a Liebert Customer Engineer to adjust the APM’s output voltage over a range of
-5% to +16% of nominal. The output voltage adjustment can be used to compensate for any drop in
line voltage that may occur when the UPS is a significant distance from the protected load. In
addition, it can be used to optimize the UPS output voltage for loads that operate more efficiently at a
voltage different from the nominal Liebert APM output voltage.
!
WARNING
Risk of arc flash and electric shock. Can cause equipment damage, injury and death
The UPS input and output must be protected with external overcurrent protection devices. In
maintenance mode, the input and output busbars remain energized and present an electric
shock hazard.
NOTE
To parallel non-208 input voltages, an upstream transformer must drop the input voltage to
208V before the paralleling gear.
