Technical data

6. Troubleshooting
6.1. Power failure
The control system continues with the process after a power
failure. The pre-selected conditions remain saved even during an
automatic process.
In the event of a power failure in the drying phase, the batch may
become unusable. Whether the batch can be saved or not
depends on the drying phase in which the product was when the
power failure occurred.
It is important to distinguish between the main drying phase and
the 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 by a power failure.
If the product is in the main drying phase, we recommend aerating
the unit, taking out the product and storing it in a deep-freeze. The
defrosted condensate must be drained off prior to the next start.
6.2. Insufficient vacuum
Special attention must be paid to the high-vacuum valves. The
drain valve, the aeration valve as well as the rubber valves must
be checked.
After disconnection of the mains plug, we recommend removing
the side panels of the unit, disconnecting the hose inside the unit
from the drain valve, sealing the hose end with a rubber stopper
and evacuating the unit. If the unit now reaches the necessary
operating pressure, there is a leak in the valve. This may be
caused by residues from the drying process, fluff from cleaning
cloths or wear of the O-rings of the valve.
To eliminate this problem, we recommend evacuating and aerating
the unit through the drain valve so that any particles that the unit is
evacuated and vented by means of the drain valve so that any
deposits are removed. If necessary, the O-rings must be replaced.
If the leak cannot be eliminated in this way, the drain valve must
be cleaned or replaced.
Operating Manual Freeze Dryer ALPHA 1-4 LSC / ALPHA 2-4 LSC Troubleshooting • 73