Nor-Lake General Laboratory Refrigerators & Freezers - Manual (Page 4)

Figure 1 shows the time switch set to defrost at 2:00 a.m., 8:00 a.m., 2:00 p.m., and at 8:00 p.m.
The fail-safe pointer indicates that the system will revert to cooling thirty minutes after a normal
defrost cycle began should a malfunction occur. WARNING: The fail-safe feature is a safety
mechanism and should never be used to control the length of the defrost period. This feature is
provided to protect the contents of the freezer from damage should the system fail to revert to the
cooling cycle because of mechanical difficulties.
Note: The time switch shown in the illustration is factory set to provide four defrosts per day. This
setting should provide adequate defrosting for even the most heavily used system. If experience
shows that the four set defrost periods are more than necessary, one or more of the knurled
setscrews may be removed. AT LEAST ONE OF THE KNURLED SET SCREWS MUST BE
LOCATED ON THE LARGE LOWER DIAL AT ALL TIMES.
COLD WALL UNITS
The cold wall models employ evaporator tubing embedded in the sidewalls, back, and top of the
unit. During the refrigeration process, heat is removed through the evaporator tubing and expelled
through the condensing unit. Because of the cold wall design, it will be necessary to occasionally
manually defrost the freezer models. To do this, unplug the unit and open the door. Wipe the
cabinet dry when defrosting is complete. With cold wall refrigerators, condensation may form on the
interior of the cabinet and should be periodically wiped dry.
Cold Control Adjustment
The temperature control knob is located on the top of the cabinet behind the facade. To make a
small increase or decrease in the internal cabinet temperature, rotate the control knob as needed.
Enzyme Freezer Only
The Enzyme Freezer is equipped with a programmable controller to control the settings. The
controller, which is located on the facade of the unit, is factory set. Please see the separate
instructions that are included on the operation of this controller.
GENERAL MAINTENANCE
PERIODIC CLEANING
Beginning with the initial installation, the interior surfaces of the cabinet should be periodically
wiped down with a solution of warm water and baking soda. This solution will remove any odors
from spillage that has occurred. The exterior of the cabinet should also be cleaned frequently with a
commercial grade of glass cleaner. Caution: Never use an abrasive or alkaline solution to clean
these units. Wipe dry after cleaning.
Important: Monthly cleaning of the condenser coil located on top of the cabinet should be done.
This cleaning will aid the heat transfer characteristics of the refrigeration system and increase its
efficiency. Dust, dirt, and lint will tend to accumulate on the fins of the condensing unit. This
obstruction will affect the flow of air through the condenser, thereby lowering the efficiency of the
system. A wire brush or a brush with stiff bristles can be used to loosen these particles that are
attached to the fins so that they may be removed with a vacuum cleaner. Failure to keep the
condenser coil clean and clear of obstructions could result in temperature loss and damage
to the compressor.
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