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7: Troubleshooting
Refer to the following if your freeze dryer fails to operate properly. If the suggested
corrective actions do not solve your problem, contact Labconco for additional
assistance.
Labconco freeze dry systems that are clean, dry and without samples should reach a
vacuum of 0.133 mbar within 10 minutes and should achieve an ultimate vacuum of
0.040 mbar within 18 hours when the refrigeration is operating. If the freeze dryer does
not obtain a satisfactory vacuum, perform the following maintenance tests:
Vacuum Pump
First make sure that the vacuum pump operates. If it fails to operate, check the
electrical connections of the freeze dryer to the power source and then check the
electrical connection of the vacuum pump to the freeze dryer. If the vacuum pump has a
power switch, make sure it is turned on.
Note: If the vacuum pump is plugged
directly into a wall outlet for troubleshooting purposes, the vacuum START
button much be initiated on the display screen. If the vacuum START button is
not initiated, the vacuum vent valve will remain open and the vacuum reading will
remain on HIGH.
If the vacuum is not adequate when the vacuum pump is operating,
proceed with the following steps:
1. If using a rotary vane vacuum pump, check the oil and ensure it is clean and
clear. If the oil looks cloudy or has any particulates, replace the pump oil.
Sometimes it may be necessary to flush the pump with clean oil several times.
To flush the pump, run the pump 5 to 10 minutes to allow the oil to warm up.
Drain the oil and refill with clean oil. Repeat as necessary.
a. Check the oil level in the pump. Ensure it is filled to the correct level.
2. Check vacuum hose connections from the pump to the freeze dryer and try
running the unit.
If vacuum problems continue, consider obtaining a second vacuum gauge capable of
reading a vacuum of 0.010 mbar. It is often useful in determining if the vacuum pump is
operating properly and the vacuum sensor reading is accurate.
3. Isolate the pump by disconnecting the vacuum hose from the freeze dryer.
Deadhead the pump by inserting the vacuum sensor from a secondary vacuum
gauge into the end of the vacuum hose and observe the vacuum reading
obtained. Confirm the pump can achieve an ultimate vacuum less than 0.010
mbar or approximately 10 microns. If an inadequate vacuum reading is obtained,
the pump has most likely failed and may need to be replaced or rebuilt.
