Rack-Mounting Accessories; Ventilation Requirements; Thermal Protection; Overheating Detection - HP 8114A Service Manual

Rack-Mounting Accessories

Ventilation Requirements

Thermal Protection
the HP 8114A:
Note that Option lJN2, Rear Panel Connectors, cannot be retrofitted,
but must be specified when initially ordering an instrument.
The HP 8114A is fitted with two cooling fans. Make sure that there
is adequate clearance of 3 inches (75 mm) at the rear and 112 inch
(12 mm) at the top and bottom to ensure adequate airflow. If the
airflow is restricted the internal operating temperature will be higher,
reducing the instrument's reliability or causing the instrument's
thermal-protection circuits to automatically switch off the instrument.
Overheating Detection
The HP 8114A monitors its internal temperature in the region of the
power supply. If the temperature exceeds approximately 80°C the
power supply is switched off. The instrument must be switched off
to allow the detection circuit to recover (after the temperature falls
below approximately 77%).
If either of the fans is prevented from operating by a blockage, or
the power supply to the fans is interrupted, the power supply is
automatically switched off within approximately 10 seconds. Note
that after the fault condition has been fixed, the instrument must be
switched off to allow the detection circuit to recover.
HP 8114A Service Guide
Installing the HP g114A