Allied Telesis AT-9900s Switches - Manual (Page 9)

Installation Guide
9
9. Connect the supply cable wires to the circuit breaker.
10. Turn on the PSU by pushing in the Run/Standby control with a small
diameter pin.
Checking LEDs
LEDs indicate the operational status on the faceplate of each PSU and on the
front panel of the switch.
After you have inserted the PSU and powered on the switch, check the LEDs for
correct operation by using the following tables.
Table 1: LEDs on the power supply unit and fan-only module
LED State Description
Fault Red The temperature of the PSU has exceeded the limit of
75º C (167
º F), or the FOM has failed.
PWR Green A PSU is installed in the switch and is receiving power.
FOMs do not have this LED.
Table 2: PSU LEDs on the switch
LED State Description
PSU 1 Green PSU 1 is installed and supplying power to the switch.
The voltage output is within specification.
Red PSU 1 is installed in the switch and has exceeded its
recommended temperature threshold of 75º C
(167º F), or the fan has failed.
A FOM is installed in the switch and has failed.
The bay is empty.
Off A FOM is installed and operating at an acceptable
speed.
For AT-9924T and AT-9924SP models, this LED is
always off because a FOM is not required.