Owner`s manual

The cooling system is designed to keep system components at an optimal
operating temperature. It is important to keep the front and rear doors
free of obstructions, leaving a clear space of 39.4 inches (1 meter) from the
cabinet to maximize air intake.
The blowers, located in the lower half of the cabinet, draw air in through the
doors and push air up through the card cages. The air is directed through a
duct to cool the console load device if there are no VAXBI card cages in the
system. The airflow continues through the top of the card cages, through
the power regulators, and out the top of the front and rear doors. A fan
cools the power and logic box.
The system has safety detectors for the cooling system: an airflow sensor
and a thermostat are installed above the power regulators in the top of
the cabinet. Extreme conditions activate these detectors. Under extreme
temperatures, the thermostat shuts off all output power (including power
at the two unswitched outlets) at the AC power controller. In this condition
the battery backup unit is disabled and will not provide power. If the
airflow to your system is seriously blocked for an extended period of time,
the airflow sensor shuts off the power supply. If either condition occurs,
call your Digital customer service engineer.
System Components 2–15