Powerware 9315s - Manual (Page 64)

7--12 Powerware 9315 Parallel Capacity/Redundant System with PHP SSBM
164201373 Rev. A 092402
7.3.2 Redundant CBP Mode (Optional)
The Parallel Capacity/Redundant system can be protected against failure of the
CBP breaker to close if an electrically interlocked System Maintenance Bypass
(SMB) with Redundant CBP controls has been provided. The Redundant CBP
controls protect the critical load against power losses caused by CBP close failures
during manual or automatic operations.
Redundant CBP operations can be recognized by an alarm condition at the SSBM
and the following breaker conditions:
CBP OPEN
CBS OPEN
FBP OPEN
MIS CLOSED
MBP CLOSED
CAUTION:
The critical load is not protected while the Parallel Capacity/Redundant
system is in Maintenance Bypass or Bypass mode.
Once Redundant CBP operation has occurred, the SSBM must be isolated to allow
CBP breaker maintenance without impact on the system’s critical load. To achieve
SSBM isolation, the Redundant CBP controls have been interlocked with the
System Maintenance Bypass controls. To exit from Redundant CBP operation, the
SMB control switch must be turned to the TO MAINT position. This action opens
the UPS system MIS breaker and places the the UPS system fully into Maintenance
Bypass mode.
After the CBP breaker has been repaired, the UPS system can be transferred from
Maintenance Bypass mode to Bypass mode as described above.
Figure 7---7 shows the path of electrical power through the Parallel
Capacity/Redundant system when operating in Maintenance Bypass mode.