Welbilt Delfield 4000P Series, Installation, Operation And Maintenance Manual

14 

Part Number: 9294045C  03/22

Operation 

Section 3

FREEZERS

Plug the unit in to begin operation. At initial start-up or 

anytime power is disconnected, then reconnected to the 

unit, the control will start the unit in defrost.
The unit can be turned on and off by pressing the on/off 

button on control. The unit will begin in a defrost cycle if it 

is turned on at the control. 
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, then the freezing cycle will begin. 
After initializing and the defrost cycle, the electronic 

temperature control will cycle the compressor, evaporator 

fan motor, and condenser fan motor to maintain box 

temperature at the control setting.
With the doors closed, the temperature of the cabinet 

should reach 0°F (-18°C) on freezers in about one hour 

after the freezing cycle begins. 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.

During normal operation the evaporator fan may cycle 

and/or pulse independently of the compressor. Consult 

the service manual or contact Technical Support at 

1-844-724-CARE if you are unsure of the proper 

function.

Electronic Temperature Control Location & Adjustment

The control is located in the control box at the rear of the 

unit. It is factory set at mid-range to maintain about -3°F 

(-18°C) box temperature. To adjust for colder temperatures, 

press and hold the set button until the current set point 

appears and is blinking on the screen.  Press the down 

arrow to adjust to the desired temperature.  Press the set 

button to save the temperature.  
To adjust for warmer temperatures, press and hold the set 

button until the current set point appears and is blinking 

on the screen.  Press the up arrow to adjust to the desired 

temperature.  Press the set button to save the temperature 

Freezer Automatic Defrost

The control is set to defrost every 5 hours. The maximum 

defrost duration is 35 minutes. 

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. The 

unit can also be put into a manual defrost by pressing and 

holding the snowflake button on the control. 
When the control enters the defrost mode, whether manual 

or automatic, it switches on the compressor and condenser 

fan motor, and energizes the hot gas solenoid to warm the 

evaporator coil and melt all frost accumulated during the 

previous refrigeration cycle. The control will continue the 

defrost cycle for a MAXIMUM of 35 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 two minutes AFTER 

the compressor and condenser fan motor have begun 

operating. 

EVAPORATOR FAN OPERATION

Cooling Cycle

Defrost Cycle

Compressor 

On

Compressor 

Off

Compressor 

Off  Refrig. / 

On Freezer

Evap Fan

Evap Fan

Evap Fan

R290 

Refrigerators

On

On

On

R290 Freezer

On

Off

Off