Defrost Chamber; Clean Door Gasket; Vacuum Relief Port - Thermo Scientific Fisher Scientific 900 Series Operating And Maintenance Manual

Defrost Chamber

Clean Door Gasket

Vacuum Relief Port

Thermo Fisher Scientific
1. Remove all product and place it in another freezer.
2. Turn the unit off and disconnect it from the power source.
3. Turn off the battery switch (O). See Figure 4-6.
4. Open all of the doors and place towels on the chamber floor.
5. Allow the frost to melt and become loose.
6. Remove the frost with a soft cloth.
7. After defrosting is complete, clean the interior with a non-chloride
detergent. Rinse thoroughly with clean water and dry with a soft cloth.
8. Plug unit in and turn power switch on.
9. Turn the battery power switch to Standby mode ( ).
10. Allow the freezer to operate empty overnight before reloading the
product.
The door gasket should be cleaned monthly, minimum. Using a soft cloth,
remove any frost build-up from the gasket and door(s). The door gasket
may need to be cleaned more frequently if dirt or excessive frost build-up
prevents the door from closing properly.
The exterior door gasket provides an excellent seal to protect product,
provide an energy efficient thermal barrier to keep cold air in and room
temperature air out, and reduce frost build up on the inner doors.
Because the door gasket seals so well, a vacuum can be created after a door
opening. Warm air enters the cabinet, cools and contracts, creating a
vacuum that pulls the door in tightly against the seal.
To equalize the pressure inside the cabinet after a door opening requires
1.5-3.0 cu.ft. of ambient air to be drawn into the cabinet. The amount of
air required to equalize the pressure varies depending on the cabinet size,
cabinet temperature, duration of door opening, inventory volume and the
temperature/humidity of the ambient air. The unit is designed with a
"vacuum relief port" that allows the pressure to be equalized.
Section 4 Section 4
Maintenance Maintenance
Model 900 Series 4-3