Operation
Section 3
20
Part Number: 9294839 03/17
R290 Freezer
Freezers are factory set at mid-range to maintain about -2ºF
(-19ºC) box temperature.
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 freezing cycle cools the box to the
set temperature.
4. Then the 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 R290 Evaporator Fan Operation
on page 21.
R290 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 seven hours since the last defrost cycle
OR if evaporator coil temperature drops below -30ºF (-34ºC)
(indicating excessive frost on the coil).
R290 Freezer Manual Defrost
If a manual defrost is desired, hold the upper left 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.
When the control enters the defrost mode, it switches off
the evaporator fan motor, compressor and condenser fan
motor, and switches on the defrost heater to warm the
evaporator coil. Thereby melting all frost accumulated
during the previous refrigeration cycle. The digital
temperature display will now read dEF. The control will
continue the defrost cycle for a MINIMUM of six minutes
and 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 until the evaporator reaches
-5°F (-21°C) or two minutes AFTER the compressor and
condenser fan motor have begun operating. The digital
temperature display will continue to read dEF until the
evaporator has returned to normal freezing temperatures
(up to 30 minutes).
R290 TEMPERATURE CONTROL & DISPLAY
V
V
Control Display
Operation / Indication
Status
Displayed
Comments
Normal (°C)
Temp. [°C] Unit depends on setting
(parameters in control)
Normal (°F)
Temp. [°F]
Show set-point
Temp.
Set to Defrost
dEF / Temp
Depends on setting
(parameters in control
or as chosen by upper
left button)
Sensor 1 defect
E01
Air sensor
Sensor 2 defect
E02
Coil sensor
High temperature alarm
Hi
Automatically switching
at 2 sec rate
Low temperature alarm
Lo
Line voltage too hight
uHi
Line voltage too low
uLi
