Vertiv Liebert EXM - Battery Mode-Requires Optional External Battery Cabinet; Auto-Restart Mode; Bypass Mode; ECO Mode (Single-Module UPS System Only)

Vertiv™ | Liebert® EXM
™
50-250kVA, 480V, 60Hz User Manual | 57
Example 2
• Four 50kVA power modules installed
• Nameplate rating capacity = 200kVA
• One power module in redundant mode
• Configured capacity = 150kVA
•Load = 150kVA
Load percentage will be calculated based on available power module capacity = 200kVA capacity. In the
event of a single power module fault, the system will signal a Loss of Redundancy Alarm and a Power
Hardware Mismatch Alarm. The system will continue in double-conversion mode and provide up to 150kVa
capacity.
Example 3
• Four 50kVA power modules installed
• Nameplate rating capacity = 200kVA
• One power module in redundant mode
• Configured capacity = 150kVA
•Load = 175kVA
Load percentage will be calculated based on available power module capacity = 200 kVA capacity. The
system will signal a Loss of Redundancy Alarm. The system will continue in double-conversion mode and
provide up to 200kVA capacity.
Battery Mode—Requires Optional External Battery Cabinet
When utility AC power fails, the Liebert
®
EXM
™
protects the critical load by instantaneously
channeling battery power from optional External Battery Cabinets to the inverter, which
continues supporting the critical load without interruption. When utility power returns and is
within acceptable limits, the Liebert
®
EXM
™
automatically shifts back to Normal mode, with the
rectifier powering the critical load.
Auto-Restart Mode
The battery may become exhausted following an extended AC utility failure. The inverter shuts
down when the battery reaches the End of Discharge voltage (EOD). The UPS may be
programmed to “Auto Recovery after EOD” after a delay time if the AC utility recovers. This mode
and any delay time may be programmed by the commissioning engineer.
Bypass Mode
When the Liebert
®
EXM
™
is in bypass mode, the load is directly supported by utility power and is
without battery backup protection.
The Liebert
®
EXM
™
’s static transfer switch will shift the load from the inverter to bypass mode
without interruption in AC power if the inverter is synchronous with the bypass and any of the
following occurs:
•inverter fails
• inverter overload capacity is exceeded
• inverter is manually turned off by user
ECO Mode (Single-Module UPS System Only)
When ECO mode is selected, the Liebert
®
EXM
™
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
NOTE
If the inverter is asynchronous with the bypass, the static switch will transfer the load from the
inverter to the bypass WITH interruption in AC power to the critical load. This interruption will be
less than 13.33ms in 60Hz. This interruption time may be altered by modifying the Output
transfer interrupt time setting.