Technical data
Please proceed in the same way in case of a leak in the aeration
valve.
Check the lid seal for dirt or damage. If necessary, it must be
cleaned or replaced.
Ensure that the entire surface of the ground-in stopper of the
attachable drying chamber is greased with vacuum grease.
When using drying chambers with several connections for rubber
valves, the valves should be removed and the connections should
be sealed with rubber stoppers. To check the valves, they are
connected one after the other and tested under vacuum.
Check the vacuum sensor for soiling, e.g. water residues.
The vacuum sensor has a limited life time due to its design
principle. Vacuum sensors are available as spare parts (VSP62,
part no. 125468).
Check the vacuum display with a suitable testing unit (if available).
In order to locate a possible leak, we recommend that the vacuum
measuring sensor is directly connected to the inlet side of the
vacuum pump. If the warm vacuum pump reaches a final pressure
of at least 0.011 mbar, the vacuum pump and the measuring
system can be considered as being in working order. There is
probably a leak in the unit if the insufficient vacuum is not caused
by an insufficient ice condenser temperature.
Check the oil level in the vacuum pump, change the oil if it is
contaminated and carry out pressure test.
If the above-mentioned steps show no result, the next step is to
check all of the small flange connections (see chapter 4.8.2) and
especially the position of the centering rings. It is usually not
necessary to grease the sealing rings with high-vacuum grease.
The vacuum pump does not switch on:
The vacuum pump is equipped with a protective switch for the
drive motor.
(Please refer to the separate operating manual of the vacuum
pump.)
General information:
The vacuum checks should be carried out when the ice condenser
is deep-frozen.
6.3. Unit does not work
If the display does not work after the mains switch has been
actuated, the following tests must be performed:
Is the mains switch plugged in?
Check the on-site fuses.
Check the automatic circuit breaker 1F1 at the back panel of
the unit.
74 • Troubleshooting Operating Manual Freeze Dryer ALPHA 1-4 LSC / ALPHA 2-4 LSC