Operation
3.3.2OK to Transfer
The OK to Transfer status message will be displayed when the bypass line and UPS output power are both available, their voltage, frequency and phase synchronization are matched within specifications, and the Static Switch Disconnects are closed (ON). An alarm message may be displayed to indicate Load On Bypass (Figure 42). If no alarm is displayed, the operating status is Load On UPS (Figure 43).
When the OK to Transfer message is displayed, you can perform a manual transfer of the load from the UPS system to bypass or a manual retransfer of the load from bypass to the UPS system.
Use the Load Transfer Procedures screen when performing a manual transfer. Refer to 3.4.2 - Load Transfer Procedures.
Figure 42 Load on bypass (UPS available)
THREE BREAKER MAINTENANCE BYPASS SWITCHBOARD
BFB | MBB |
| Critical |
| Load |
| AC Output |
BIB | MIB |
UPS MODULE
Static
Switch
Disconnects 
Static
Bypass
Switch
Bypass CB
CONTROL POWER
RIB
INPUT |
CB |
MAIN INPUT
SWITCHGEAR
Controls |
| |
Rectifier/ | Inverter | |
Charger | ||
|
MBD |
OUTPUT
CB
Battery
The UPS system control logic will initiate an automatic transfer to bypass if an overload condition exceeds the system current versus time window or if a UPS fault is detected. An automatic retransfer to the UPS system may be initiated when recovering from system overloads lasting less than five min- utes. Refer to 3.5 - Automatic Operations.
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