UNDERSTANDING UPS OPERATION
Eaton 9395 UPS (450–825 kVA) Installation and Operation Manual
S
164201725 Rev 4
www.eaton.com/powerquality
6-34
MAINTENANCE
BYPASS PANEL
Output
from
UPS
MIS
To UPS
Rectifier
Input
RIB:
Rectifier Input Breaker
BIB:
Bypass Input Breaker
MIS:
Maintenance Isolation Breaker
MBP:
Maintenance Bypass Breaker
MBP
Backfeed
Contactor
K5
K3
AC Input
Battery
Breaker
BATTERY SYSTEM
UPS
CRITICAL LOAD
DISTRIBUTION UNIT
NOTE
If installing a maintenance bypass, a minimum of two separate feeds with upstream feeder breakers, or a single feed with two
upstream feeder breakers, must be provided: one for the UPS or rectifier input breaker (RIB) (if installed) and one for the maintenance bypass
input. DO NOT use a single feed or a single feeder breaker to supply both the UPS or RIB and the maintenance bypass. If a bypass input
breaker (BIB) is installed in the maintenance bypass and a single-feed UPS is being installed, a single feed to the maintenance bypass is
acceptable for supplying both the UPS and the bypass.
Static
Switch
(Supplied by Others)
Output
Contactor
AC Input
RIB
BIB
To UPS
Bypass
Input
Figure 6‐29. Simplified Dual-Feed UPS with Maintenance Bypass Panel