User manual

46 Chapter 6 Operating Instructions
NXr UPS Module And Parallel System 30kVA ~ 200kVA User Manual
Warning: hazardous battery voltage
The UPS battery and connecting terminals remain energized at hazardous voltage levels at all times.
The following procedures are used to isolate one UPS from a parallel system.
1. Press the EPO switch of the UPS to be isolated.
2. Open the external a.c .input switch and BCB of the UPS. In split bypass configuration, it is required to open both
external a.c input switches.
At this point, other UPSs report Parallel Comm. Fail, which is normal. Other UPSs continue to power the load through
the inverter.
3. Open the external a.c output switch of the UPS.
4. Wait for 10 minutes before carrying out UPS maintenance or repair.
6.7 Insertion Procedures (Of One UPS In A Parallel System)
The procedures are used to re-integrate a UPS that has been previously isolated from a parallel system. It is
assumed that the installation is completed and the system has been commissioned by authorized personnel.
1. Close the external a.c output switch of the UPS to be re-integrated.
2. Close the external a.c input switch and BCB of the UPS. In split bypass configuration, it is required to close both
external a.c input switches.
3. Press and hold the INVERTER ON button of the UPS for 2s.
The inverter starts up, and the inverter indicator starts flashing in green color. When the inverter is ready, the UPS
transfers to parallel operation with other UPSs, and the inverter indicator goes to a continuous on state.
The UPS is in normal mode, and the UPS indicator states are as listed in Table 6-3.
Table 6-3 UPS indicator state
Indicator State
Rectifier indicator Green
Battery indicator Off
Bypass indicator Off
Inverter indicator Green
Output indicator Green
Status indicator Green
6.8 Emergency Power Off (EPO) Procedures
The EPO switch is designed to switch off the UPS in emergency conditions (that is, fire, flood, and so on). The
system will turn off the rectifier, inverter and stop powering the load immediately (including the inverter and bypass),
and the battery stops charging or discharging.
If the input mains is present, the UPS’s control circuit will remain active; however, the output will be turned off. To
remove all power from the UPS, the external feeder breaker should be opened.
Note
In a parallel system, the EPO only isolates the UPS whose EPO has been activated.
6.9 Automatic Restart
In the case of a mains failure, the UPS draws power from the battery system to supply the load until the batteries are
depleted. When the UPS reaches its end of EOD threshold, it shut will down.
The UPS will automatically restart and enable output power: