Freezer Models 403 & 407 Temperature Control Operation; Evaporator Fan Operation - Delfield 400 Series Installation, Operation And Maintenance Manual

International Work Top & Undercounter Refrigerators & Freezers Original User Manual
Freezer Models 403 & 407 Temperature Control Operation
After the unit is connected to power it will automatically
begin operating. With the doors closed, the temperature
of the cabinet should reach 0°F (-18°C) on freezers in about
one hour. Continuous opening and closing of the doors will
hamper the unit's ability to maintain optimum temperature.
The electronic temperature control constantly monitors
box temperature as well as evaporator coil temperature
to maintain consistent product temperatures. As an added
energy-saving feature, the electronic controller will switch
the evaporator fan motor on and off with the compressor
and condenser fan motor.
At initial start-up or anytime power is disconnected, then
reconnected to the unit, the control will delay all operations
for a short time (up to 10 minutes.) While in this delay
period, the control initializes the control parameters and
confirms that the temperature sensors and circuits are
operational.
Service Alert: During normal operation the evaporator fan
may cycle and/or pulse independently of the compressor.
Consult the service manual or contact Technical Support at
1-800-733-8829 if you are unsure of the proper function.
IMPORTANT NOTE REGARDING FREEZERS:
After initializing, the control will immediately enter a
DEFROST mode. The compressor and condenser fan as well
as the evaporator fan will remain off until initial defrost
is complete. This initial defrost cycle may take up to 15
minutes to complete, at which time the freezing cycle will
begin.
Whenever the freezer is plugged in, and the control has
completed initializing including the initial defrost cycle
(see above), the electronic temperature control will cycle
the compressor, evaporator fan motor, and condenser fan
motor to maintain box temperature at the control setting.

Evaporator Fan Operation

400 Refrigerator
400 Freezer
4000 Refrigerator
4000 Freezer
8
For customer service, call (800) 733-8829, (800) 773-8821, Fax (989) 773-3210, www.delfield.com
Cooling Cycle
Compressor On
Evap Fan Evap Fan Evap Fan
On Off
X
X
X
X
Freezer Automatic Defrost
The control also monitors compressor total running time
and will enter a defrost cycle after total compressor running
time is greater than 5-hours since the last defrost cycle OR
if evaporator coil temperature drops below -34°F (indicating
excessive frost on the coil).
Freezer Manual Defrost
If a manual defrost is desired, simply 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.
When the control enters the defrost mode, whether manual
or automatic, it switches off the evaporator fan motor,
compressor and condenser fan motor, and switches on the
defrost heater to warm the evaporator coil and melt all frost
accumulated during the previous refrigeration cycle. The
control will continue the defrost cycle for a MINIMUM of 8
minutes and a MAXIMUM of 30 minutes depending on the
amount of frost accumulated on the evaporator coil.
After the defrost cycle is complete, the control returns
to a normal refrigeration cycle, however the evaporator
fan motor will not switch on for 2 minutes AFTER the
compressor and condenser fan motor have begun operating.
Electronic Temperature Control Location & Adjustment
Never turn the knob more than 1 dial number and always
allow 8 hours for temperature stabilization before making
any additional adjustments. The control is located in the
control box at the rear of the unit (see photo).
factory set at mid-range to maintain about -3°F (-18°C) box
temperature. To adjust for colder temperatures, turn the
knob clockwise. For warmer temperatures, turn the knob
counter-clockwise. Turn the knob fully counter-clockwise to
turn the refrigeration system off.
Compressor Off Compressor Off
Evap Fan Evap Fan
On Off On
X
X
X
X
Defrost Cycle
Evap Fan
Off
X
X
X
X
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