Powerware 100160 kVA manual Bypass Mode Parallel

Understanding UPS Operation

7.3.3 Bypass Mode – Parallel

In Bypass mode, the output of the system is provided with three-phase AC power directly from the bypass input. While in this mode, the output of the system is not protected from fluctuations, spikes, or power outages from the source. No power filtering, conditioning, or battery support is available to the output of the system in the Bypass mode of operation.

The parallel system automatically switches to Bypass mode if it detects a UPM overload, UPMs unavailable, load fault, or internal failure.

Figure 7-6 shows the path of electrical power through the parallel system when operating in Bypass mode.

Bypass Input	UPM Input
	UPM 1
Battery
	UPM 2
Battery
	UPM 3
Battery
	UPM 4
Battery

Module Tie Cabinet

UPM 1 Output

UPM 2 Output

UPM 3 Output

UPM 4 Output

	Breakers
Main Power Flow	Closed	Output to
	Open	Critical
		Load

Figure 7-6. Path of Current through the UPMs in Bypass Mode – Parallel

In a parallel redundant or capacity type system, each module operates similar to a single module, but in parallel with each other. The bypass source for the load is derived from the bypass input of one, two, three, or four modules, depending on the system configuration through the internal continuous-duty static switches. If a module is taken offline, the other modules remain online to support the load. If more modules than can support the load must be taken offline, the load must be transferred to maintenance bypass or shut down.

7-12EATON Powerware® 9390 UPS (100–160 kVA) Installation and Operation Manual S 164201604 Rev B powerware.com