Since a couple weeks ago, cr2-esams has been alerting about FPC 0 XM 0 Chip regularly crossing Juniper's built-in 75C threshold. And its fans are spinning at high speed.
Overall temperature in the racks has been pretty stable, and no other devices has been alerting.
In addition to a risk of damaging the equipment, the intermittent alarms can't be downtimed without risking muting future important alarms.
For reference, Juniper's recommendations about MX480 airflow are the following:
http://www.juniper.net/documentation/en_US/release-independent/junos/topics/reference/requirements/mx480-cabinet-airflow.html
https://www.juniper.net/documentation/en_US/release-independent/junos/topics/reference/requirements/mx480-clearance.html
And the impacted rack: https://racktables.wikimedia.org/index.php?page=rack&tab=default&rack_id=1967
A few possible options after talking to Mark and looking at Racktables:
- Adding a 1 or 2 U fan plate
Similar to https://www.amazon.com/AC-Infinity-CLOUDPLATE-cooling-Theater/dp/B00ZQMP6RO/
We need to make sure the power and air-flow fits
- Make sure all the unused Us in the rack are blocked
- Redirect cold air to the MX intakes
- Power-off unused servers (if any)
- Longer term, cr1 and csw will be decomed, which should lower the temperature
Other suggestions and pictures of the rack are welcome.
@mark, next time you're onsite, could you look at what can be done?