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To eliminate this fault we recommend that the unit is evacuated and
vented by means of the drain valve so that any residue (e.g. collected
parts) is removed. If necessary, the O-rings must be replaced.
If the leakage cannot be eliminated in this way, the drain valve must
be cleaned or replaced.
Check the sealing of the lid for dirt or damages. If necessary, the
sealing must be cleaned or replaced.
Check if the whole surface of the ground-in socket of the mountable
drying chamber has been greased evenly and completely with
vacuum grease.
When using drying chambers with several connections for rubber
valves the valves should be taken off 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 pollution such as water residue.
The vacuum sensor has a limited life time due to its design principle
(see also chapter 7.3.1). Vacuum sensors are available as a spare
part.
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 vacuum flange 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 presumed to be in working order. There is probably a leak in the
unit if insufficient vacuum is not caused by an insufficient ice
condenser temperature.
Check the oil level in the vacuum pump, change oil if dirty, and carry
out a pressure test.
If the above-mentioned steps show no result, the next step is to check
all small flange connections (see chapter 4.7.2) 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 separate operating manual).
General information:
The vacuum checks should be carried out when the ice condenser is
deep-frozen.
50 • Error Correction
Operating Manual Freeze Dryer ALPHA 1-2 LDplus
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