Cooling - Lab.gruppen PLM Series Operation Manual

For situations where rapid removal and replacement
of units is of paramount importance, Method 2 may
be used as it does not involve any permanently
secured fixing at the rear of the unit.
Figure 5-2
Method 1:
Use washer for fixed installation.
Figure 5-2
Method 2:
Use tube for slide-on installation.

5.4 Cooling

The PLM uses a forced-air cooling system with
airflow from front to rear, allowing high continuous
power levels without thermal problems. (Front-to-rear
airflow is preferable as air at the front of a rack is
cooler than that at the rear in nearly all situations.)
Never attempt to reverse the airflow. The operation
of the PLM's cooling system is dependent on front-
to-rear airflow; it will not function effectively with
airflow in the opposite direction.
Make sure an adequate air supply is provided in
front of the PLM, and that the rear of the PLM has
sufficient space to allow the exit air to escape. If the
PLM is rack-mounted, never operate the unit with
any front or rear rack doors or covers in position.
Also note that any unused rack spaces should have
solid blanks fitted (not ventilation blanks) to ensure
efficient air circulation. Leaving gaps in between
items of equipment degrades the effectiveness of
forced-air cooling.
If installing one or more PLM's in a rack with other
fan-cooled equipment, be sure that all the other
units also use front-to-rear airflow for cooling. If
this precaution is not observed, there is a risk of
overheating, as units with the reverse airflow will
be drawing in air which has already been heated by
the PLMs units.
The PLM is equipped with a sophisticated
temperature sensing system which protects
it from any overheating which may occur
as a result of inadequate ventillation. Should
a power output channel overheat, the temperature
sensing circuits will mute that channel until the
temperature reduces to a safe level. If the power
supply overheats, another sensing circuit will mute
all channels until the power supply temperature
reduces to a safe operating level.
Always make sure that the dust filters behind the
detachable front panel are clean to ensure maximum
possible airflow.
If the device malfunctions as a result of
dirty dust filters, any required repairs are
not covered by the warranty.
PLM Series Operation Manual 11
INsTALLATION 5