Emergency Module Off (Optional); 2.14.6 Remote Emergency Power Off; Figure 34 Emergency Modules Off; Figure 35 Remote Emergency Power Off - Emerson Liebert NXL 250 kVA Operation And Maintenance Manual

2.14.5 Emergency Module Off (Optional)

The Emergency Module Off (EMO) mode will transfer the critical load to the bypass line and remove
power from all UPS module components except the controls, bypass circuit breaker and the static
switch.
If installed, the Emergency Module Off control is a guarded pad next to the display touchscreen
(Figures 2, 6 and 7).
Lift the cover and press the pad. The load will be transferred to bypass, and the DC source (MBD),
input and output circuit breakers will be opened (tripped). Refer to 2.15.13 - Shutdown—Single
Module UPS System.

Figure 34 Emergency modules off

Bypass
Input
CB1

2.14.6 Remote Emergency Power Off

The Remote Emergency Power Off control is a user-provided switch located remotely from the UPS
system. It usually is installed in the same room as the critical load equipment. This mode can also be
initiated by an automatic contact closure in the same external circuit as the manually operated
switch.
When the Remote Emergency Power Off switch is operated, all UPS circuit breakers are opened,
including the bypass circuit breaker. All power through the UPS is removed from the load. Typically,
the REPO circuit also opens the circuit breakers that provide power to the bypass lines and the UPS
controls. Refer to 2.15.13 - Shutdown—Single Module UPS System.

Figure 35 Remote emergency power off

Bypass
Input
CB1
® ™
Liebert NXL
BFB
DC Source
MBD
BFB
DC Source
MBD
DC Bus
DC Bus
28
Operation
Module
Output
CB2
Module
Output
CB2