When install high-power optics such as 400G ZR and ZR-M on MX304 with MX304-LMIC16 line card, it is recommended to set the temperature-sensor manually, refer to http://https://apps.juniper.net/hct/model/?component=QDD-400G-ZR-M

If follow the CLI document, the policy commands listing on MX304 might not work.

https://www.juniper.net/documentation/us/en/software/junos/cli-reference/topics/ref/statement/chassis-adc-temperature-sensor.html

user@router# show chassis cb 0 | display set 

set chassis cb 0 temperature-sensor Intake_A temperature-threshold fans-to-normal-speed 5
set chassis cb 0 temperature-sensor Intake_A temperature-threshold fans-on-intermediate-speed 15
set chassis cb 0 temperature-sensor Intake_A temperature-threshold fans-on-full-speed 20
set chassis cb 0 temperature-sensor Intake_A temperature-threshold fans-on-full-speed-if-failed-fan 17
set chassis cb 0 temperature-sensor Intake_A temperature-threshold yellow-alarm 50
set chassis cb 0 temperature-sensor Intake_A temperature-threshold yellow-alarm-if-failed-fan 50
set chassis cb 0 temperature-sensor Intake_A temperature-threshold red-alarm 70
set chassis cb 0 temperature-sensor Intake_A temperature-threshold red-alarm-if-failed-fan 70
set chassis cb 0 temperature-sensor Intake_A temperature-threshold fire-shutdown 75
set chassis cb 0 temperature-sensor Onboard temperature-threshold fire-shutdown 130

[edit]
user@router# commit 
commit complete

After commit, the threshold didn't update based on the given settings.

user@router# run show chassis temperature-thresholds | grep "FAN|Item|Intake_A"             
                    Fan speed   Yellow alarm   Red alarm   Fire Shutdown
Item                 Normal High  Normal Bad fan  Normal Bad fan   Normal
CB Intake_A Temp Sensor          65  70    90    90    95    95    100

One workaround is change the temperature sensor from "Intake_A" to "Intake_A Temp Sensor" and commit the changes, the temperature-threshold

got updated correctly. 

user@router# show chassis | display set 

set chassis fpc 0 pic 0 port 0 speed 400g

set chassis cb 0 temperature-sensor "Intake_A Temp Sensor" temperature-threshold fans-to-normal-speed 5

set chassis cb 0 temperature-sensor "Intake_A Temp Sensor" temperature-threshold fans-on-intermediate-speed 15

set chassis cb 0 temperature-sensor "Intake_A Temp Sensor" temperature-threshold fans-on-full-speed 20

set chassis cb 0 temperature-sensor "Intake_A Temp Sensor" temperature-threshold fans-on-full-speed-if-failed-fan 17

set chassis cb 0 temperature-sensor "Intake_A Temp Sensor" temperature-threshold yellow-alarm 50

set chassis cb 0 temperature-sensor "Intake_A Temp Sensor" temperature-threshold yellow-alarm-if-failed-fan 50

set chassis cb 0 temperature-sensor "Intake_A Temp Sensor" temperature-threshold red-alarm 70

set chassis cb 0 temperature-sensor "Intake_A Temp Sensor" temperature-threshold red-alarm-if-failed-fan 70

set chassis cb 0 temperature-sensor "Intake_A Temp Sensor" temperature-threshold fire-shutdown 75

[edit]

user@router# show chassis 

cb 0 {

  temperature-sensor "Intake_A Temp Sensor" {

    temperature-threshold {

      fans-to-normal-speed 5;

      fans-on-intermediate-speed 15;

      fans-on-full-speed 20;

      fans-on-full-speed-if-failed-fan 17;

      yellow-alarm 50;

      yellow-alarm-if-failed-fan 50;

      red-alarm 70;

      red-alarm-if-failed-fan 70;

      fire-shutdown 75;

    }

  }

}

user@router# commit 

commit complete

[edit]

user@router# run show chassis temperature-thresholds | grep "FAN|Item|Intake_A"  

                    Fan speed   Yellow alarm   Red alarm   Fire Shutdown

Item                 Normal High  Normal Bad fan  Normal Bad fan   Normal

CB Intake_A Temp Sensor          5  15    50    50    70    70     75