Manual

Operating Manual Freeze Dryer ALPHA 1-4 LDplus / ALPHA 2-4 LDplus Error Correction  53
6. Error Correction
6.1. Power Failure
The control system continues the process after a power failure. The
preselected conditions remain saved during the process run. The
process times, the total time and the section time are reset.
In the event of a power failure during the drying process the batch
may become unusable. Whether the batch can be saved depends
on the drying phase in which the product was when the power
failure occurred.
It is important to distinguish between the main drying and final
drying phase:
The product is in the final drying phase when the residual moisture
has reached approx. 5 %. Below this value the product is generally
not damaged in the event of a power failure.
If the product is in the main drying phase we recommend that the
unit is vented, the product taken out and stored in a deep-freeze.
Before further operation the defrosted condensate must be drained.
6.2. Insufficient Vacuum
Special attention must be paid to the high-vacuum valves. The drain
valve, the micro-aeration valve and the rubber valves must be
checked.
We recommend that after disconnecting the mains plug the left side
panel of the unit is unscrewed and then the hose inside the unit is
detached from the drain valve, the pipe connection is sealed with a
rubber stopper, and the unit evacuated. If the unit will now reach the
necessary operating pressure there is a leakage in the valve. This
is caused by residue from the drying process, fluff from cleaning
cloths or wear and tear of the O-rings of the valve.
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.