Emerson NX Manuel D’Utilisation

g. Close all DC breakers.

Risk of improper operation. Can cause equipment damage.
Do not close the battery breaker until the DC bus is above 540VDC.

h. Press the “Start Inverter” button on touchscreen. Press “Confirm” on the popup window and 

the load will be energized from the UPS inverter.

Risk of equipment damage. If an abnormal situation occurs during this startup procedure, 

open the input circuit breaker and investigate the problem. Call Liebert Services if help is 

required.

This section lists typical step-by-step instructions.
1. Before applying power to each UPS module, determine the position of the following circuit 

breakers and switches of each UPS module:

• 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 Output Breaker (MOB)—Verify that this external breaker is open or tripped.
• 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. Apply power to all modules:

• If the equipment does not have CB1 installed, the rectifiers of all modules will start 

automatically.

• If CB1 is installed, close CB1 for all modules and allow the rectifiers on all modules in the system 

to start.

• Verify that the rectifier on each module has started and that the LCD is fully functional before 

proceeding.

• Make sure none of the UPS module inverters has started.

3. After all module rectifiers are started and the LCDs are functional (with no parallel module 

warnings or faults):

• Close the MOB for Module 1.
• Close the BFB for Module 1 and ensure the BPSS is active for the module (inverter is Off). The 

BPSS should automatically activate when ready.

• Close the MOB for the remaining modules.
• Close the BFB the remaining modules.
• Verify that all module static switches are active.

4. Select the “Start Inverter” icon on the USER LCD of Module 1. It is recommended that you start 

with Module 1 and then continue in order when instructed to do so.

5. Verify that “Inverter pending on command” message is displayed in the INVERTER section of the 

Status screen.

6. Repeat Steps 4 and 5 for the remaining modules.

NOTE
After the “Start Inverter” icon on the last module is selected, all inverters will turn On 

NOTE
It will not be necessary to check the “Inverter pending on command” on the last module.