Online Mode_ Dual Input_ Parallel Units - Delta Modulon DPH series User Manual

3.2.8 Online Mode_ Dual Input_ Parallel Units

In online mode (parallel), the total loads will be equally shared by the parallel UPSs. If one
of the parallel units fails and its load is less than the total capacity of the remaining parallel
units, the failing UPS's output will be switched off and its load will be equally shared by
the remaining parallel units. If the failing UPS's load is larger than the total capacity of the
remaining parallel units, all UPSs' inverters will turn off and the total loads will be supplied
by bypass power. During online mode, each UPS's tri-color LED illuminates green and each
UPS's LCD shows the text 'On-Line' in the upper right corner. Please refer to Figure 3-25
for the path of electrical power through the parallel UPSs in online mode.
1
Delta or non-Delta External Maintenance Bypass Cabinet
BYPA.
MAIN
Batteries
2
Delta or non-Delta External Maintenance Bypass Cabinet
BYPA.
MAIN
Batteries
Q3
UPS
Q2 Q0
Rectifier
Q1
Q5
Q3
UPS
Q2 Q0
Rectifier
Q1
Q5
(Figure 3-25: Online Mode Diagram_ Dual Input Parallel Units)
Static Switch
Inverter
Static Switch
Inverter
3-25
3 Operation Modes
Q4
Q4
LOAD