Specifications

Hardware Reference 25
C613-03084-00 REV A
PSU and FOM LEDs
Power Supply Units (PSUs)
At the rear of the AT-9900 Series switch chassis are two power supply bays.
AT9924T and AT-9924SP switches are supplied with a single PSU, either AC or
DC, and a blanking panel covering one PSU bay pre-installed at the factory as
standard.
AT-9924T/4SP switches are supplied with a single PSU, either AC or DC, and a
FOM pre-installed at the factory as standard.
The figure below shows an AT-9900 Series switch with a PSU and FOM
installed.
Figure 1-9: Rear panel of the AT-9900 Series switch
PSUs are hot-swappable and when two PSU are fitted they will load share. If
you install two PSUs this allows for power supply redundancy.
Both AC and DC power supplies are available. However, combinations of AC
and DC power supplies are not supported.
Each PSU and FOM contains an EPROM allowing for command line interface
identification of the modules. The EPROM will contain information including
the type of module, serial number and revision of the PSU. This information
will be available through the command line interface.
PSU specifications are described in “Power supply units” on page 5.
LEDS on the PSU and FOM are described in“LEDs and What They Mean” on
page 23.
How to install a PSU or FOM in the switch is described in the AT-PWR01 Quick
Install Guide.
Table 1-12: LEDs on the AT-PWR01 and AT-FAN01
LED State Function
Fault Red There is either a fan failure, or the temperature
has exceeded the limit of 70º C (158
ºF).
PWR Green A PSU is installed in the switch and is receiving
power. The FOM does not have this LED.
CAUTION: DISCONNECT POWER CORD PRIOR TO REMOVAL OF PSU
CAUTION: DISCONNECT ALL POWER CORDS TO DISABLE SYSTEM POWER
AC INPUT
100-240V
50/6 0Hz
3.0A
PWR
GOOD
FAULT
AT-PWR01
AT-FAN01
FAULT