IBM SAN50C-R, Installation, Service And User Manual

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and part information (serial number and revision). When connected to nominal 110
or 220 VAC input each PSU provides 300 W of output power.
In the default configuration and with all three PSUs installed, the IBM SAN50C-R
switch has N+1 PSU redundancy. The only power redundancy mode available is
redundant; combined mode is not supported on this platform.
To obtain grid redundancy with the IBM SAN50C-R switch an Automatic Transfer
Switch (ATS) is required. An ATS is a third party power switch that connects to
two power sources (usually different power grids) to provide uninterrupted power
to downstream devices in the event of one of the sources failing. Connect one of
the PSUs to the ATS and each of the other PSUs to separate grids. It is not
necessary to connect all three PSUs to the ATS..
In this way the ATS is not a single point of failure. If it fails then the two PSUs
directly connected to the grids supply enough power. Similarly, if one of the grids
fails, two PSUs remain functional – one through the ATS and the other directly
connected to the other grid.
The APC AP7721 has been verified to work with the IBM SAN50C-R switch.
If insufficient power is available to the IBM SAN50C-R switch the system puts the
remaining PSUs in shutdown mode to prevent heat damage to them. A PSU in this
mode can be identified by the green input LED and red output LED. To reset a
PSU in this state the AC input must be removed for at least 2 seconds. This can be
done by manually cycling the power switch of the PSU off and on over a 5 second
interval.
Support for Power Redundancy with Two Online PSUs
The IBM SAN50C-R Switch running NX-OS 8.1(1), or later, supports power
redundancy with two online PSUs. To enable power redundancy in this scenario,
FCoE ports must be brought to ADMIN DOWN state. The power supplies in a
IBM SAN50C-R Switch work in the following power modes when FcoE ports are
in ADMIN DOWN state.
rav00059
ATS
PSU
PSU
IBM SAN50C-R Switch
PSU
Power Grid B Power Grid A
Figure 11. Connecting an ATS for power grid level redundancy
Figure 12. Power modes when FcoE ports are in ADMIN DOWN state
Chapter 1. Introducing the SAN50C-R
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