Mx10016 Fan Tray Controllers - Juniper MX10016 Hardware Manual

If you want to replace an existing fan tray while the router is running, remove only one fan tray. The router
continues to operate for a limited time with a single operating fan tray without triggering a thermal alarm.
CAUTION:
operating.
CAUTION:
The internal fan control board in each fan tray contains LEDs for the associated fan tray controllers and
LEDs for the three SFBs directly behind the fan tray.

MX10016 Fan Tray Controllers

Two fan tray controllers provide the control logic and power to hot-insert and hot-remove a fan tray. The
fans in each fan tray are numbered 0 through 20.
The system continually monitors the temperature of critical parts across the chassis and adjusts the chassis
fan speed according to the temperature.
Software controls the fan speed. Under normal operating conditions, the fans in the fan tray run at less
than full speed.If one fan tray controller fails or appears missing (such as when an SFB is being replaced),
the other fan tray controller sets the fans to full speed. This enables the router to continue to operate
normally as long as the remaining fans cool the chassis sufficiently. Use the show chassis fan command
to see the status of individual fans and the fan speed. For example:
user@device> show chassis fan
Item
Fan Tray 0 Fan 0
Fan Tray 0 Fan 1
Fan Tray 0 Fan 2
Fan Tray 0 Fan 3
Fan Tray 0 Fan 4
Fan Tray 0 Fan 5
Fan Tray 0 Fan 6
Fan Tray 0 Fan 7
Fan Tray 0 Fan 8
Fan Tray 0 Fan 9
Fan Tray 0 Fan 10
To avoid a thermal alarm, do not remove both fan trays while the router is
The chassis will shut down if a thermal alarm is raised for more than 3 minutes.
Status
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
RPM Measurement
7950 Spinning at normal speed
7800 Spinning at normal speed
7800 Spinning at normal speed
7950 Spinning at normal speed
7650 Spinning at normal speed
7650 Spinning at normal speed
7650 Spinning at normal speed
7650 Spinning at normal speed
7650 Spinning at normal speed
7650 Spinning at normal speed
7650 Spinning at normal speed
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