Powerware 9315 - Manual (Page 39)

33 Powerware 9315 Parallel Redundant System I & O
164202013 Rev. D 041599
Understanding Parallel
Redundant Operation
With the parallel redundant system, the UPS system continues to function
automatically to supply AC electrical power to the critical load. There are three
operation modes in this system:
· In Normal mode, the UPS system functions normally as described in the
PowerwareR 9315 Operation manual provided with the UPS system. In the
parallel redundant system, power leaves the UPS module from its AC output
and is routed into the designated MOB in the parallel cabinet. As the system is
in Normal mode, the MOBs are closed and clean power is routed directly to the
AC output of the parallel cabinet and then to supply the critical load.
· In Battery mode, the battery cabinet supplies DC power, which maintains UPS
operation. The battery supports the critical load through the parallel cabinet’s
AC output.
·
In Bypass mode, interunit signaling is used by each UPS to determine if its
designated MOB is closed and if the redundant module is on bypass or normal.
This information causes differences to the usual bypass operation of the UPS
system.
The following description provides the operating mode differences between the
parallel redundant and single UPS module systems.