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Liebert
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NX
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18
2.5.1 Startup—Single Module System
This section lists typical step-by-step instructions.
If the installation includes a Maintenance Bypass, power may already be supplied to the critical load
equipment through the Maintenance Bypass. If there is no power to the critical load, apply power
through the UPS bypass line per the following procedure.
During startup, power is supplied to the critical load through the UPS (internal) bypass line while the
UPS system is being energized. Depending on the reason for the UPS system shutdown, power may
be present in the bypass line. To determine this, check the Monitor/Mimic Display screen after control
power is available.
1. Before applying power to the UPS module, determine the position of the following circuit breakers
and switches:
• Optional Input Circuit Breaker (CB1)—Verify that this breaker on the front of the UPS cabinet
(see Figures 2 and 3) is in the open position.
• Module Battery Disconnect (MBD)—Verify that this external breaker is open or tripped. If DC
source cabinets are used, verify that breakers on all the cabinets are open.
• Bypass Circuit Breaker (BFB)—This circuit breaker (see Figures 2 and 3) should be open.
2. Start the module:
a. Close the Rectifier Feed Breaker (RFB). This breaker is external to the UPS; it may be in the
Maintenance Bypass Cabinet.
b. Wait until the HMI finishes booting up. This may takes several minutes.
c. Optional Input Breaker (CB1) installed: Close CB1
d. Close Bypass Backfeed Breaker (BFB). The equipment mimic screen will display and the
Static switch will turn On and fans will be powered On.
e. The load will now be powered by the bypass.
f. On the HMI, verify that the Rectifier and Booster are Green.
!
WARNING
Risk of electric shock. Can cause equipment damage, personal injury and death.
The following procedure provides power to the critical load distribution system. Verify that
the critical load distribution is ready to accept power. Make sure that personnel and
equipment are ready for the critical load distribution system to be energized.
NOTE
If the system was shut down in response to an “Emergency Off”, there may be alarm messages
on the touchscreen that describe system conditions before (or at the time of) the shutdown.
Some or all of the alarm conditions may have been resolved. To clear these alarm messages,
turn Off control power (see Figures 2 and 3). Wait at least 10 minutes for the control power
circuitry to completely de-energize. After 10 minutes, turn control power back On.
!
WARNING
Risk of electric shock and high short circuit current. Can cause equipment damage, personal
injury and death.
If the UPS has been shut down for maintenance, verify that all of the UPS system doors are
closed and latched. All test equipment must be removed from the system. All electrical
connections must be secure.
NOTE
If power to the critical load is already supplied through this breaker, keep this breaker closed.
NOTE
The rectifier will start automatically once it is powered, when either RFB or CB1 closed.