Thermal Monitoring And Control; Thermal Alarm - Lenovo ThinkSystem DS Series Hardware Installation And Maintenance Manual

Thermal monitoring and control

The storage enclosure system uses extensive thermal monitoring and takes a number of actions to ensure
component temperatures are kept low, and to also minimize acoustic noise. Air flow is from the front to back of the
enclosure.
Symptom
If the ambient air is below
25ºC (77ºF), and the fans are
observed to increase in speed,
then some restriction on
airflow may be causing
additional internal temperature
rise.
NOTE: This is not a fault
condition.

Thermal alarm

Symptom
1. Ops panel Module Fault
LED is amber.
2. Fan Fail LED is
illuminated on one or more
PCMs.
104 Troubleshooting and problem solving
Cause
The first stage in the thermal
control process is for the fans to
automatically increase in speed
when a thermal threshold is
reached. This may be caused by
higher ambient temperatures in
the local environment, and may
be perfectly normal.
NOTE: This threshold
changes according to the
number of disks and power
supplies fitted.
Cause
Internal temperature exceeds a
preset threshold for the
enclosure.
Recommended action
1. Check the installation for any airflow
restrictions at either the front or back of
the enclosure. A minimum gap of 25 mm
(1") at the front and 50 mm (2") at the rear
is recommended.
2. Check for restrictions due to dust
build-up. Clean as appropriate.
3. Check for excessive re-circulation of
heated air from rear to front. Use of the
enclosure in a fully enclosed rack is not
recommended.
4. Verify that all blank modules are in place.
5. Reduce the ambient temperature.
Recommended action
1. Verify that the local ambient environment
temperature is within the acceptable
range. See also "Environmental
requirements" (page 147).
2. Check the installation for any airflow
restrictions at either the front or back of
the enclosure. A minimum gap of 25 mm
(1") at the front and 50 mm (2") at the rear
is recommended.
3. Check for restrictions due to dust
build-up. Clean as appropriate.
4. Check for excessive re-circulation of
heated air from rear to front. Use of the
enclosure in a fully enclosed rack is not
recommended.
5. If possible, shut down the enclosure and
investigate the problem before continuing.