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Product Service: Domestic 1-800-522-7658, International 816-333-8811
Chapter 7: Troubleshooting
5. Check all vacuum connections and joints and
tighten any loose hose clamps or fittings.
If any repairs are required on your Freeze Dry System,
contact your local laboratory supply dealer. If
satisfaction is not obtained through the dealer service
network, please call Labconco. Repairs should only be
undertaken by a competent technician or through an
authorized Labconco service agency.
Refrigeration Module
Operation
Under a no-load condition, the FreeZone Plus 2.5 Liter
Freeze Dryer can achieve a collector temperature of
–84°C or lower, depending on ambient temperature and
humidity. If the collector temperature does not reach
–84°C within 40 minutes, then the refrigeration module
is not functioning properly.
The refrigeration system in your freeze dry unit is a
“cascade” type system. Simply, a cascade system is
two vapor-compression refrigeration systems in series,
connected together via a heat exchanger. Each system
has a compressor, condenser, capillary tube metering
device and an evaporator. During operation the
evaporator of the “high stage” system refrigerates the
condenser of the “low stage” system. This takes place
in the heat exchanger. The low stage and high stage
systems are balanced by design, however, sometimes
that balance can be disrupted during operation and the
unit will not function properly. If the unit is
overloaded, or if the unit is defrosted and restarted in a
short time interval, system unbalance is possible. If
system unbalance occurs, turn the freeze dry unit off
and allow the unit to soak at ambient temperature for 2
to 4 hours.
