Dell Power Supply C8000 Owner's Manual page 258

Table 5-1. Fan Module (Fan Controller Firmware) Thermal Behavior Per Sled
Fan Module BMC (Processor/Memory)/Server Enclosure Temperature Status
Status
OK/OK
Two fan System throttling,
modules fail
After 90 seconds has
passed, the system will
be forced to shut
down
Three fan System force
modules fail shutdown
a. Open loop (curve A) is fan speed control (FSC) curve with default mode.
b. Refer to the Fan Controller Firmware Response section for more information.
c. Open loop (curve B) is FSC curve with emergency mode.
d. Open loop (curve C) is FSC curve with fan failure mode.
Fan Controller Firmware Response
Refer to the tables below when troubleshooting enclosure fan noise and for
the FC firmware responses to the possible PWM duty cycle values.
Table 5-2. Case Scenario 1
Interval (30 secs)
Interval 1
Interval 2
Table 5-2 lists the FC firmware responses in case scenario 1:
• Interval 1 — If the calculated value of the PWM is higher than 100%, the
FC firmware will send a signal to the fan to operate at 100% duty cycle and
trigger sled throttling.
• Interval 2 — If the calculated value of the PWM duty cycle is still higher
than 100% again, the FC firmware will send a signal to the fan to operate
at 100% duty cycle and trigger sled throttling for 1 hour.
258
Troubleshooting
OK/Fail
System
throttling,
After 90
seconds has
passed, the
system will be
forced to shut
down
System force
shutdown
PWM Results
PWM > 100%
PWM > 100%
Fail/OK
System throttling,
After 90 seconds has
passed, the system
will be forced to shut
down
System force
shutdown
Fan Controller Firmware Action
1 Sets PWM = 100%
2 Sled throttling mechanism is active
1 Triggers sled throttling for 1 hr.
Fail/Fail
System
throttling,
After 90 seconds
has passed, the
system will be
forced to shut
down
System force
shutdown