FLEX200 / recommended device temperature

StefanZ · May 2023

Our FLEX200 reports back a constant, yet toasty 67°C CPU temperature (via Syslog, at info-level / severity: 4).

The rack it sits in is in an air conditioned room, it has no active components next to it top or bottom and airflow is given.

CPU average is reported as 6 (percent I guess) and memory at around 40.

Is that a normal temperature for those conditions? Or might there be an issue?

What is the maximum / shutdown temperature for the readout?

Manual states "max. 40°C ambient temperature", but since we are now around 25°C at max in that room, I am a bit worried for the coming summer and also the overall longtime stability of the FLEX200.

Zyxel_Jeff · May 2023

Hi @StefanZ

Thanks for your inquiry.
Currently, the maximum shutdown temperature is 85 °C.
The 6% CPU usage with 67 °C belongs to a higher temperature.
We suggest you can check whether there are other devices are nearby your USG Flex200.
If so, please separate them at a safe distance to avoid the high-temperature issue(as the following user guide described).

Besides, you can use CLIs to check the current CPU and temperature.
Router> show cpu average
Router> show cpu all
Router> show cpu status
Router> debug hardware fan-get

Here is another discussion about the high temperature, it could provide you with some hints.

https://community.zyxel.com/en/discussion/16864/device-temperature-has-exceeded-system-threshold

Thanks.

StefanZ · May 2023

Thanks for the reply.

The FLEX200 is at the bottom of the rack, 2 Slots above it are empty (4 height units), there is nothing below or to the sides and the air is cooled to 25°C currently.

Also the table states that the FLEX200 isn't suited for rack mounting, though it comes with rack mount brackets included… Talking about "mixed signals" :-)

So what temperature range should be expected for my scenario?

And what can cause the overheating?
I would put my money on a poorly attached heat sink…

Current results in command line:

Router> show cpu status
CPU utilization: 7 %
CPU utilization for 1 min: 3 %
CPU utilization for 5 min: 4 %

Router> debug hardware fan-get
Sensor[0]:68 degree
Sensor[1]:38 degree
Sensor[2]:43 degree
FAN[0]:0 RPM
FAN[1]:0 RPM
FAN[2]:0 RPM
FAN[3]:0 RPM

When I get back to the appliance next time, I will move it to a new, mobile rackmount so I can test it outside the server room at general ambient conditions. But those are likely to be way worse soon than the server room, since summer is coming.