Power Supply/Cooling Faults; Thermal Control - IBM 1269-3S2 Installation, Service And User Manual

IBM System Storage DCS9900 1269-3S2 Storage Expansion Unit Installation, Service, and User Guide

4.4.2 Power Supply/Cooling Faults

1 Ops Panel FAULT
2 An AMBER LED on
3 Audible Alarm

4.4.3 Thermal Control

The IBM System Storage DCS9900 3S2 Storage Expansion Unit uses extensive thermal monitoring and
takes a number of actions to ensure component temperatures are kept low and also to minimize acoustic
noise. Air flow is from front to rear of the enclosure.
Symptom
If the ambient air is cool
(below 25 °C) 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.
38
Symptom
LED AMBER.
one or more Power
Supply/Cooling
Modules.
sounding.
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 normal.
Note: This threshold
changes according to the
number of drives and power
supplies fitted.
Cause Action
1 Any power 1 Check Power On/Off Switch on rear of Power
fault. Supply/Cooling module is switched ON.
2 A fan failure. 2 Check AC connection to Power Supply/Cooling
module is live.
3 A thermal
condition 3 Disconnect the Power Supply/Cooling module
which could from AC power and remove the module from the
cause PSU system. Re-install: if problem persists, replace
overheating. Power Supply/Cooling Module.
4 Reduce the ambient temperature.
Action
1 Check the installation for any airflow
restrictions at either the front or rear
of the enclosure. A minimum gap of
25mm at the front and 50mm 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 the front, use
in a fully enclosed rack installation is
not recommended.
4 Check that all blank modules are in
place.
5 Reduce the ambient temperature.