Powerware UPS Sidecar Powerware 9390 - Manual (Page 31)

EATON Powerware ® 9390 UPS Sidecar Installation and Operation Manual S 164201586 Rev E www.powerware.com 3-1
Chapter 3 Understanding Operation
The UPS Sidecar can be configured for either maintenance bypass or parallel
redundant operation.
3.1 Maintenance Bypass Configuration
3.1.1 UPS Mode
When the Maintenance Bypass switch (MBP) is open and the Maintenance Isolation
switch (MIS) is closed, conditioned and protected power from the UPS is routed
through the MIS to the critical load.
If the optional Bypass Input Breaker (BIB) is installed, power is supplied to the UPS
through the BIB, and the UPS rectifier and bypass input terminals are jumpered
together. If the optional BIB and Rectifier Input Breaker (RIB) are installed, the UPS
rectifier is supplied power through the RIB and the UPS bypass is supplied power
through the BIB, for a dual-feed system. In a single-feed system, the BIB and RIB
input terminals are jumpered together and power is supplied to the UPS rectifier and
bypass input terminals from a single source.
Figure 3-1 shows the path of electrical power through the UPS Sidecar when
operating in UPS mode.
AC INPUT
TO UPS
OUTPUT TO
CRITICAL LOAD
UPS SIDECAR
RIB
(OPTIONAL)
BIB
(OPTIONAL)
MIS
MBP
AC INPUT
TO BYPASS
TO UPS RECTIFIER
INPUT
FROM UPS OUTPUT
TO UPS BYPASS
INPUT
MAIN POWER FLOW IN UPS MODE
MAIN POWER FLOW IN MAINTENANCE BYPASS MODE
Figure 3-1. Path of Current Through the UPS Sidecar in UPS Mode
Figure