Switch Maximum Operating Temperature C9300/C9500

[brianw360]

I'm having a quandary with temperatures on switches.  The data sheet for these devices state that the max operating temp is 45-55C.  Yet, I get an output like this: 

OR227-XW1>sho env temp
Switch 1: SYSTEM TEMPERATURE is OK
Inlet Temperature Value: 46 Degree Celsius
Temperature State: YELLOW
Yellow Threshold : 46 Degree Celsius
Red Threshold : 56 Degree Celsius

Outlet Temperature Value: 54 Degree Celsius
Temperature State: GREEN
Yellow Threshold : 105 Degree Celsius
Red Threshold : 125 Degree Celsius

Hotspot Temperature Value: 80 Degree Celsius
Temperature State: GREEN

Yellow Threshold : 105 Degree Celsius
Red Threshold : 125 Degree Celsius

I'm mainly concerned about the Hotspot temp.  80C is 176F,  105C is 221F, and 125C is 257F.  

What sensor is the "max operating temp" value on the data sheet pointing to?  Inlet, Hotspot or Outlet.  Has anyone mentioned to Cisco the ambiguity of this?

[Reza Sharifi]

Here is some more info from the Architecture White Paper for the 9300 series:

The Cisco Catalyst 9300 Series Switches support hot-swappable and field-replaceable fans in the rear of the chassis. They are variable-speed, modular fans (three individual fan modules) supporting airflow from the front and sides to the back. The fan unit is responsible for cooling the entire chassis and interfacing with environmental monitors to trigger alarms when conditions exceed thresholds. The fan modules contain thermal sensors to detect ambient temperature and adjust the fan speed. The chassis supports a hardware failure of up to one individual fan or fan tray; the remaining fans will automatically increase their speed to compensate and maintain sufficient cooling. If the switch fails to meet the minimum number of required fans, the switch shuts down automatically to keep the system from overheating.

Cisco Catalyst 9300 Series chassis are equipped with on-board thermal sensors to monitor the ambient temperature at various points and report thermal events to the system so that it can adjust the fan speed.

https://www.cisco.com/c/en/us/products/collateral/switches/catalyst-9300-series-switches/nb-06-cat9300-architecture-cte-en.html

HTH

[balaji.bandi]

how the calculation done look at the configuration guide :

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9300/software/release/16-8/command_reference/b_168_9300_cr/system_management_commands.html#wp2125621861

[nladegoan30]

Was the solution determined? I'm seeing the same output as well.

from the Architecture White Paper for the 9300 series, https://www.cisco.com/c/en/us/products/collateral/switches/catalyst-9300-series-switches/nb-06-cat9300-architecture-cte-en.html

and the config. guide, https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9300/software/release/16-8/command_reference/b_168_9300_cr/system_management_commands.html#wp2125621861

It appears the difference should be 15 degrees but the temperature output shows

Yellow Threshold : 105 Degree Celsius
Red Threshold : 125 Degree Celsius

Does it need to be looked into ? My main concern is, as the thresholds are showing 105 and 125 Degree Celsius, the threshold alerts won't be triggered until it reaches 105Celsius which is 221 Fahreinheit.

[nladegoan30]

It appears to be a cisco bug. Please check the below link:

https://bst.cisco.com/bugsearch/bug/CSCvx96576

Hope this helps

[Ramblin Tech]

“What sensor is the "max operating temp" value on the data sheet pointing to?”

The max operating temp in data sheets refers to the ambient temp of the environmental chamber in which the unit was tested. The inlet sensor would come closest to measuring ambient temp. The max temp can have a range because the ability of a device to dissipate its heat depends on altitude (ie, air density).