Liebert UPS System - Manual (Page 70)

Chapter 5 Operation of Display Panel
64
2001-11-08 UL33-0400L 12:30:20
Inv. On Units: ID 1
A(B) B(C) C(A)
221
11.8 12.3 12.5
50.2 50.1 50.1
1.41 1.40 1.41
Input Breaker Close 11£ -08 12:09
Output Breaker Open
UPS in Normal Mode
Batt. Boost Charging
11£ -08 12:09
11£ -08 12:09
11£ -08 12:09
11£ -08 12:09
Mains
Bypass
Local
System
Battery
220 221
Byp. Breaker Close
Out
Power KW
Cap. KVA
Load%
Crestor
Factor
OK
Transfer with Interupt
, Confirm
Fig. 5-40 Bypass to inverter prompt
From inverter to bypass mode with interruption:
If the bypass voltage or frequency exceeds the synchronized range and the UPS is
in inverter mode, the system must let the user to confirm and accept the power
interruption danger before pressing the inverter stop key to shutdown the output of
the inverter. The user can also cancel the shutdown operation, as shown in Fig. 5-
41. If the bypass voltage restores to normal before the user makes the confirmation,
the UPS will transfer to bypass operation mode automatically, and at the same time
the prompt window will disappear soon.
2001-11-08 UL33-0400L 12:30:20
Inv. On Units: ID 1
A(B) B(C) C(A)
221
11.8 12.3 12.5
50.2 50.1 50.1
1.41 1.40 1.41
Input Breaker Close 11£ -08 12:09
Output Breaker Open
UPS in Normal Mode
Batt. Boost Charging
11£ -08 12:09
11£ -08 12:09
11£ -08 12:09
11£ -08 12:09
Mains
Bypass
Local
System
Battery
220 221
Byp. Breaker Close
Out
Power KW
Cap. KVA
Load%
Crestor
Factor
OK
This operation leads
to output shutdown,
Confirm or cancel
C
Fig. 5-41 Transfer to bypass prompt
Overload due to shutdown: The parallel operation system is in inverter mode, if the
load capacity exceeds the total capacity of the remained UPS units when shut
down one UPS unit. The UPS that is to be shut down will display a prompt window
to ask the user to confirm before shutting down, as shown in Fig.5-42. If the load is
reduced before the user makes confirmation, there will be no overload for the
remained UPS units, this UPS unit will shut down automatically, and the Prompt
window will disappear automatically, the functions of the keys in the Keypad display
window will restore to normal functions.