Procedures For Completely Powering Down Ups; Procedures For Complete Ups Shutdown While Maintaining Power To Load - Liebert NXC 30kVA User Manual

60 Chapter 7 Parallel System And LBS System
1. If the UPS is connected with a battery, just close the battery external distribution switch or three terminals 'BAT+',
'BAT-' and 'BAT N' (see Figure 5-3 for details). Then close the rectifier input switch Q1 and neutral line switch Q6.
At the moment, the system is power on, and the startup screen pops up. Refer to Refer to 4.2.1 Start Screen.
2. Close the bypass input switch Q2.
At this moment, confirm that the LCD shows the bypass input supply is normal; if not, check whether the switch Q2 is
closed. Then the rectifier starts up and the alarm indicator turns solid red. About 30 seconds later, the alarm indicator
(red) is flashing (if the UPS has internal or external battery not connected) or off (if the UPS has internal or external
battery connected).
3. Close the output switch Q5, and press the ON key for two seconds.
The inverter starts up, and the inverter indicator (green) is flashing. After the inverter runs normally, the inverter
indicator turns solid green, and the inverter supplies power to the UPS.
At this point, the UPS will join the operation of the parallel system, and supply power to the load.

7.3.5 Procedures For Completely Powering Down UPS

Complete UPS shutdown and load power-off should follow this procedure. All power switches, isolating switches and
breakers are disconnected, and then UPS no longer supplies power to the load.
The following procedures will cut off the load power, making the load completely power off.
1. Pressing the EPO button of each UPS stops the operation of rectifier, inverter, static switch and battery.
2. If the UPS has internal battery, use the special tool to open the battery compartment, then pull the three terminals
'BAT+', 'BAT-' and 'BAT N' (see Figure 5-3 for details). If the UPS has external battery, disconnect the corresponding
switch of the external battery. All UPS modules should be disconnected from the batteries.
3. Disconnect the rectifier input switch Q1 and bypass input switch Q2 of each UPS. At the moment, all the internal
power supply is closed and the LCD does not display any more.
4. Disconnect the output switch Q5 of each UPS.
1. Post a label at the AC input distribution (generally far away from the UPS) to alert that the UPS maintenance is being operated.
2. Wait 10 minutes for the internal DC bus capacitance discharging. Then the UPS is completely shut down.
1. After the UPS shutdown, the load is transferred to maintenance bypass. If required, operate the maintenance bypass switch at
any time.
2. Only qualified personnel shall finish the UPS installation. This procedure can be executed after the system runs normally.
The battery terminals still have hazardous voltage after the UPS complete shutdown.

7.3.6 Procedures For Complete UPS Shutdown While Maintaining Power To Load

The following procedures are applicable for completely powering down the UPS and still keeping the power supply to
the load. Refer to the procedures in 7.3.2 Maintenance Bypass Procedures.
Warning: hazardous battery voltage
Liebert NXC 30kVA And 40kVA UPS User Manual
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