Qualstar XLS Series Technical & Service Manual page 31

Power System
Figure 2-7
Power switch/
breaker
Power
connector
Figure 2-7 Power bay components
XLS power components include the following:
• Main power disconnect switch. The single disconnect switch for the library is
a 20-amp circuit breaker.
• AC power connector. The power connector is a single-phase, 100 to 240 volt
service connection.
• Power supplies. Two to seven AC-to-24VDC power supply modules provide
power to the components within the LRM, the tape drives, and any attached
MEMs. The power supplies are configured in an N+1 arrangement, meaning that
if one fails, the others will handle the load until the failed supply is replaced. The
power supplies can be replaced while the library remains powered on. Note that
the two leftmost slots must be occupied first.
• Battery module. The battery module provides emergency power to safely shut
down the XLS if the AC power fails. It is not an uninterruptible power supply. If
AC power fails, the library immediately shuts off power to the tape drives, parks
the handler at the bottom of the cabinet, and commences an orderly shut down of
the remaining systems. The library is non-functional from the moment the AC
fails. If power returns before the shutdown is complete, the library completes the
shutdown, then restarts. The battery module can be replaced while the library
remains powered on.
XLS Library Technical Service Manual
shows the power components accessible from the rear of the LRM.
Cosmetic cover
removed
Power supplies
Battery module
(up to 7)
2
About the XLS
2-
17