Operating instructions

A power backplane integrates the supplies for power distribution, monitoring,
and control. The power supplies can be accessed and removed from the front of
the enclosure. See Chapter 4 for instructions on adding or replacing a power
supply.
The following voltages are provided: +3.3, +5.0, +12.0, -12.0 Aux (+5.0 Aux al-
ways powered). Two internal fans for each power supply cool the power supply.
The fans are temperature controlled and speed up as the power supply tempera-
ture increases.
Systems containing model FR-H7910-AA power supplies (part number 30-
50662-01) require a minimum of three power supplies if the system contains
more than 8GB of memory.
Systems containing model 3X-H7911-AA power supplies (part number 30-
10047-01) require a minimum of two power supplies. A third supply may be
added for redundancy (see next section).
N+1 Power Supply Configuration
In a redundant configuration (three 3X-H7911-AA supplies) , a power supply
may be removed for servicing without interrupting system operation. An I/O
interrupt is generated whenever the number of power supplies in operation
changes.
Two power supplies must be installed and working for the system to operate.
The system shuts down if the number of working power supplies ever falls be-
low two.
System Overview 1-15