C
HEETAH
S
ERIES
S
WITCHERS
–
C
HAPTER
12
81-9059-0570-0
Rev. C
Proprietary Information of
PESA
S
WITCHING
S
YSTEMS
,
I
NC
.
176
12.1.3
Fan Replacement Sequences
The fans that are used in all Cheetah chassis configurations are continuous duty, ball bearing, 24VDC
brushless, circulating fans. In operation, the fans are voltage-controlled by the power supplies, which
receive feedback from the system heat sensors. That is, as the heat increases, the fan voltage is
increased thus increasing the fan circulating speed and vice-versa. All fan assemblies in Cheetah
chassis are “hot swappable”.
All fan assemblies used in the Cheetah Series switchers have a continuous-
duty rating of 40,000 hours. It is recommended that predicted failure and/or
preventive maintenance schedules be implemented to replace fan assemblies
during scheduled maintenance periods for fan assemblies that have exceeded
30,000 to 35,000 hours of operation.
Since the fans are electro-mechanical devices, they will eventually fail due to wear. All fan
assemblies are monitored for proper operation and a system alarm is initiated whenever a fan is not
operating correctly or has failed.
Only authorized personnel should attempt repair or replacement of fan
components. Potential injury or equipment damage exists during fan
replacements. Always disconnect power to the fan prior to any fan
replacement.
Cooling is an integral part of the Cheetah system operation. Any fan alarm
must be addressed and corrected as soon as possible. Continued operation of
the equipment during a failed fan(s) condition could result in catastrophic
equipment failure.
Replace PESA switcher fan assemblies with only PESA-approved
replacement fan assemblies. All PESA-approved fan securing #6 hardware
are tightened to no more (non-lubricated) than a torque values of 9.6 inch-
pounds and #8 to no more than 17.8 inch-pounds.
There are two types of fan assemblies that are used for the Cheetah series, which are as follows:
•
Surface-mount fan assembly (fan is mounted externally to the surface of the chassis)
•
Flush-mount fan assembly (fan is mounted internally and is “flush” with the surface of the
chassis).
This section will address the replacement sequences for each type of assembly in each Cheetah Series
chassis.
Summary of Contents for Cheetah 1024x256
Page 235: ......
