Understanding UPS Operation
Bypass
Input
| Rectifier |
Rectifier | CB1 |
| |
Input |
|
Bypass |
K4 |
Inverter
K3
Output
(Closed)
Transformer
Path of electrical power
Battery
Figure 3-1. Path of Current Through the UPS in Normal Mode
If the utility AC power is interrupted or is out of specification, the UPS automatically switches to Battery mode to support the critical load with no interruption. When utility power returns, the UPS returns to Normal mode.
If the UPS system becomes overloaded, the UPS switches to Bypass mode. The UPS automatically returns to Normal mode when the error condition is cleared and system operation is restored within specified limits.
If the UPS suffers an internal failure, it switches automatically to Bypass mode and remains in that mode until the failure is corrected and the UPS is back in service.
3−2 | EATON Powerware® 9315 UPS |