Eaton Electrical Powerware 9315 operation manual 1. Path of Current Through the UPS in Normal Mode

Understanding UPS Operation

Bypass

Bypass

Input

K4

	Rectifier	Inverter
Rectifier	CB1
Input

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 (200–300 kVA) Operation Manual S 164201036 Rev F powerware.com