PTX10003 Cooling System Description and Airflow
The PTX10003 is cooled front to back with five fan modules (PTX10003-160C) or three fan modules (PTX10003-80C). Located in the rear of the chassis, the 98.4-W fan modules operate at 164 cubic feet per minute (CFM) at full speed under zero static pressure. Each fan module is a redundant unit containing dual counter-rotating fans. The fan modules can be hot-swapped and hot-inserted, meaning that you can replace a fan module without powering off the router or disrupting the router function.
The fan modules pull air through the front panel around the gaps between the optical transceivers. Cooling for the power supplies is also front to back, utilizing fans inside the power supplies. A separate air plenum provides air circulation to the power supplies in the entrance at the top of the chassis. There are no air filters in the PTX10003. Fans are field replaceable but a fan failure must be addressed within one minute to avoid system shutdown. Access to the fans is from the Field Replaceable Units (FRU) end of the chassis. Each fan module is composed of two individual fans per tray (10 fans per PTX10003-160C chassis and six fans per PTX10003-80C chassis). The power requirements of the PTX10003 do not allow for redundant fan modules.
PTX10003 Fan Modules
The PTX10003 fan modules are hot-removable and hot-insertable
FRUs designed for front-to-back airflow. For the PTX10003-160C, the
fan modules are numbered
4. For the PTX10003-80C, the fan modules are numbered
3. Fan modules are installed
in fan trays located below the power supplies. Each fan tray has a
fan icon label on the handle.
Figure 1 shows a PTX10003 fan module.
You remove and replace a fan module from the FRU end of the chassis. The router continues to operate for a limited period of time (30 seconds) during the replacement of the fan module without thermal shutdown.
All fan modules must be installed for optimal operation of the router.
If a fan module fails and the remaining fan modules are unable to keep the PTX10003 within the desired temperature thresholds, chassis alarms are raised and the PTX10003 might shut down.
PTX10003 Chassis Airflow
In data center deployments, position the router in such a manner
AIR OUT labels on router components
are next to the hot aisle. Figure 2 shows the airflow through the chassis.
Fan Module Status and LED Description
You can check the status of fan modules by using the show system alarms or show chassis fan commands or by looking at the LEDs next to each fan module. For example:
user@device> show chassis fan
Item Status RPM Measurement Tray 0 Fan 0 Absent Tray 0 Fan 1 Absent Tray 1 Fan 0 OK 5000 Spinning at normal speed Tray 1 Fan 1 OK 4400 Spinning at normal speed Tray 2 Fan 0 OK 5000 Spinning at normal speed Tray 2 Fan 1 OK 4400 Spinning at normal speed
Each router has a status LED (labeled
ST) for each fan module on the left of the corresponding fan module
slot. The LED indicates the fan module status.
Figure 3 shows the location of the LED next to the PTX10003-80C and PTX10003-160C fan modules.
Fan module LEDs
Table 1 describes the fan module LED states.
Table 1: PTX10003 Fan Module LED
The fan module is operating normally. The system has verified that the module is engaged, and that the fan is operating correctly.
An error has been detected in the fan module. Replace the fan module as soon as possible. Either the fan has failed or it is seated incorrectly. To maintain proper airflow through the chassis, leave the fan module installed in the chassis until you are ready to replace it.
Under normal operating conditions, the fan modules operate at a moderate speed. Temperature sensors in the chassis monitor the temperature within the chassis.
The system raises an alarm if a fan module fails or if the ambient temperature inside the chassis rises above the acceptable range. If the temperature inside the chassis rises above the threshold temperature, the router shuts down automatically.