Hot Standby Redundancy (Only For Dual Input & At Least Two Upss) - Delta Modulon DPH Series User Manual

3.3 Hot Standby Redundancy (Only For Dual Input & At
Least Two UPSs)
have a hot standby redundancy function. If you use two UPSs and wish them to work in hot
standby redundancy mode, please connect the output of UPS1 to the bypass input of UPS 2.
Please see Figure 3-28.
For more information about the hot standby redundancy application, please contact service
personnel.
In normal condition, it is the UPS 2 inverter that supplies power to the critical loads. Both
UPS 1 & UPS 2 tri-color LEDs illuminate green.
When the UPS 2 inverter becomes abnormal, the UPS 2 will automatically transfer to
bypass mode and the UPS 1 inverter will supply power to the critical loads. Under such
circumstances, the UPS 1 tri-color LED illuminates green and the UPS 2 tri-color LED
illuminates yellow.
1
BYPA.
MAIN
Batteries
2
Bypass Input
Terminals
MAIN
Batteries
(Figure 3-28: Hot Standby Redundancy Diagram (only for Dual Input & at Least Two UPSs))
Q3
Static Switch
Q2
Rectifier
Q1
Q5
Q3
Static Switch
Q2
Rectifier
Q1
Q5
3-29
Inverter
Q4
Inverter
Q4
3 Operation Modes
LOAD