Part Number: 9295040 07/17
21
Section 3
Operation
Refrigerator & Freezer Operation
• Delfield refrigerators are designed to maintain an
operational temperature of 36°F to 40°F (2°C to 4°C).
• Delfield freezers are designed to maintain an operational
temperature of 0°F (-18°C).
Power
• One door refrigerators will run after they are plugged in.
• Freezers, two & three door refrigerators have a power
switch located behind the louvered panel. Plug the unit in
and turn it on to deliver power.
Power
Switch
• Dual temperature reach-ins have two power switches
behind the louvered panel, one for the top and another
for the bottom. Plug the unit in and turn the switches on
to deliver power.
Bottom
Power
Top
Power
AT START UP
1. At initial start-up or anytime power is disconnected, then
reconnected to the unit, the control will go into defrost
mode.
2. The control will enter a DEFROST mode and the display
will read dEF. The compressor and condenser fan as well
as the evaporator fan will remain off until this initial
defrost is complete. This initial defrost cycle may take up
to 35 minutes to complete.
3. The display will continue to read dEF for an additional 30
minutes while the cooling cycle cools the box to the set
temperature.
4. Then the digital thermostat will display box temperature.
5. The temperature control will cycle the compressor,
evaporator fan motor and condenser fan motor to
maintain box temperature at the control setting. For
more information see Evaporator Fan Operation on page
22.
Manual Defrost
If a manual defrost is desired, hold the upper left display
button for five seconds or unplug the unit for several
seconds, then plug unit back in. This will cause the control to
re-initialize and then enter a defrost cycle.
Automatic Defrost
The temperature control monitors the evaporator
temperature and will turn off the compressor and condenser
fan motor when needed to allow accumulated frost on the
evaporator to clear. Additionally the freezer evaporator
fan will turn off and defrost heater will switch on to warm
the coil. During this defrost cycle, the digital temperature
display will read dEF. After the defrost cycle is complete, the
temperature control will return to a normal cooling cycle,
but the display will continue to read dEF until the evaporator
returns to normal cooling temperatures (up to 30 minutes).
The freezer evaporator fan motor will not switch on until the
evaporator reaches -5°F (-21°C) or two minutes AFTER the
compressor and condenser fan motor have begun operating.
The temperature control monitors evaporator temperature
and compressor run time to determine the proper time for
a positive defrost cycle. A defrost cycle can occur as often
as every 60 minutes under extremely heavy usage. It can
last a minimum of 2 minutes in a refrigerator or 6 minutes
in a freezer. When the controller enters the defrost mode
the compressor is shut off and will remain off until the
evaporator coil temperature exceeds:
• 41°F (5°C) or the controller reaches a time limit of 75
minutes on a refrigerated unit.
• 55°F (13°C) or the controller reaches a time limit of 35
minutes on a freezer.