118
UPS 675-1100 kVA 3..4x(225-275) kVA
1029052
User’s and Installation Guide
Revision 008
7.4 Multiple UPS distributed bypass operation
7.4.1 Starting the distributed bypass system in normal mode
To start the distributed bypass system:
1.
Unfasten the front door latches and swing the doors open on all of the UPSs (see Figure 4-2 on
page 33).
2.
If the UPSs contain input breakers (CB1), verify that all input breakers are open.
3.
Close all Module Output Breakers (MOBs).
4.
Close all UPS input feeder circuit breakers.
5.
If the UPSs contain input breakers (CB1), close all input breakers.
6.
Close all UPS Bypass input feeder circuit breakers.
7.
Close the doors and secure the latches.
8.
Observe the UPS control panel displays becoming active, indicating logic power.
9.
On any UPS, press the CONTROLS pushbutton on the main menu bar. The System Status screen
is displayed.
10. On the System Status screen, verify the UPS status is
SHUTDOWN
and the UPM status is
SHUTDOWN
.
11. Close all battery breakers.
12. Verify no alarms are active.
13. On the System Status screen, select the
UPS
command.
14. Press the CONTROLS pushbutton on the System Status menu bar. The UPS Control Command
screen is displayed.
15. On the UPS Control Command screen, select
GO ONLINE
.
16. Press the SELECT pushbutton on the UPS Command menu bar.
If Auto Bypass is enabled (factory default), the critical load is immediately supplied by the bypass
source in Bypass mode from all UPSs, until the inverter turns on and the UPSs transfer to Normal
mode. The status indicator on the UPS control panel indicates the UPS is in Bypass mode. If Auto
Bypass is not enabled, the UPS outputs remain off until the UPSs transfer to Normal mode.
17. Verify the following messages display sequentially on the UPS status line:
DC STARTING, CHARGER OFF
INVERTER STARTING
INVERTER SYNCING
ONLINE, CHARGER ON
The rectifier and inverter turn on. The inverter continues to ramp up to full voltage.
Once the inverter reaches full voltage, all UPS output contactors (K3) close and the bypass circuits
open. Power is now supplied to the critical load in Normal mode from all UPSs. It takes approximately
one minute for the UPSs to achieve Normal mode.
The NORMAL status indicator is illuminated. The UPS status indicates
ONLINE
.
The UPM status indicates
ONLINE, CHARGER ON
.
7.4.2 Starting the distributed bypass system in Bypass mode
If the inverter output of the distributed bypass system is not available and the critical load needs to be
energized:
CAUTION
In Bypass mode, the critical load is not protected from commercial power interruptions and
abnormalities.
