Thermo Scientific Fisher Scientific 900 Series Operating And Maintenance Manual page 26

Vacuum Relief Port
Maintenance
Thermo Fisher Scientific
3. The air exchange will be
audible and could last a few
minutes.
4. As the air pressure equalizes,
the door releases.
Warning Do not leave the freezer
unattended while the door is
unlatched. The vacuum could
release, resulting in a door
opening and product loss.
Observe the inner side of port periodically for frost and ice build-up.
Remove any frost with a soft dry cloth. If the tube should become clogged
with ice, it must be cleaned. Make sure during cleaning that the vacuum
relief tube is completely free of ice to prevent rapid ice formation.
Factors that can affect the performance of the vacuum relief port include:
high ambient temperature, high humidity conditions and frequent door
openings. Maintenance should be performed weekly or as needed.
Warning Failure to maintain the vacuum relief port may result in excessive
ice build up inside the tube, clogging the port, and inability to open the
door. The vacuum relief port may need to be cleaned more often with
frequent door openings and high humidity environments.
▲
Figure 4-5. Vacuum relief port
Section 4
Maintenance
▲
Model 900 Series Model 900 Series 4-5 4-5