Amb. F1 - A0
From ser. no.:
7.6 Fan management parameters
Fan start temperature
Fan OFF with compressor OFF
Fans in defrost
Fan OFF after dripping
Condenser fan stop temperature
Condenser fan start diff erential
The ir33 series controllers manage the evaporator fans in the following modes:
• always ON;
• ON only when the compressor is ON;
• ON according to evaporator and room temperature.
F0: Fan management
The fans can be always on or managed by the "fan controller", which controls them according to the temperature measured by the
defrost and virtual control probes.
The evaporator fans can be stopped in the following situations:
• when the compressor is OFF (see parameter F2);
• during defrosts (see parameter F3);
• during the dripping period (see parameter dd);
• and for a further post-dripping period (see parameter Fd);
• in defrost they can be on or off (see parameter F3).
The following values are allowed for this parameter:
F0=0 fans always ON;
F0=1 fans controlled according to the temperature diff erence between the virtual control probe and the evaporator temperature;
F0=2 fans controlled according to the evaporator temperature.
remember that if a dripping period is set (dd=0), the fans are stopped irrespective of the value of F0.
Default: F0=0 => fans always ON, not managed by the "fan controller".
F1: Fan start temperature (parameter valid only if F0 =1 or 2)
When F0=1, parameter F1 indicates the minimum diff erence between room temperature and evaporator temperature for the fans
to be started. Therefore, when:
• evaporator temperature < (virtual probe – F1-A0), the fans are ON;
• evaporator temperature > (virtual probe – F1), the fans are OFF.
When stopped, the fans can start again when the diff erence between the two probes is equal to F1+A0, where A0 is the "fan
controller" diff erential (see Figure 7.o).
When F0=2, parameter F1 indicates the absolute temperature for starting the fans, that is:
• evaporator temperature < (F1-A0), the fans are ON;
• evaporator temperature > (F1), the fans are OFF.
• if there are two evaporators and therefore two evaporator probes, control will be performed using the maximum value read by
the two probes, to ensure that the fans are started when both evaporators reach the set temperature.
• in the event of errors on the control probes, the fans are always on.
Default: F1=5 =>(if F0=1 or 2), the fans remain ON while the evaporator is 5 degrees colder than the room temperature.
F2: Fans OFF with compressor OFF (according to the value of F0)
Used to decide whether the fans must operate according to the rules set for parameter F0 (with the exception of the defrost cycle,
parameters F3, dd and Fd are displayed) or when the compressor is active.
• F2=0 => the fans are always ON (F0=0) or when requested by the fan controller (F0=1,2), even when the compressor is OFF;
• F2=1 => the fans are OFF when the compressor is OFF.
if control with two compressor steps is selected (with or without rotation, H1 or H5= 12 or 13) and parameter F2 =1, the
fans are off when both the compressors are off .
Default: F2=1 => fans OFF with compressor OFF.
F3: Fans in defrost
This is used to decide whether the fans should operate or not during the defrosts.
F3=0 => the fans operate during defrosts;
F3=1 => the fans do not operate during defrosts.
Remember that during the dripping time and post-dripping time, if specifi ed, the fans are always OFF. Default: F3=1 =>
evaporator fans OFF during the defrost.
Fd: Fans OFF for post-dripping
The fans, after defrosting, can be stopped for a further period beyond dd (in minutes), defi ned by the value of Fd. This is useful
to allow the evaporator to return to its operating temperature after defrosting, thus avoiding forcing "hot" air into the refrigerated
environment. In the event of management by fan controller, the time Fd does not need to be set, as the controller starts the fans
again when the evaporator reaches its operating temperature. If the "fan controller" is active (F0=0), when assigning to Fd a value
other than zero, the fans remain OFF for a time equal to the value of Fd, irrespective of the evaporator temperature. Default: Fd=1
=> 1 minute stop for post-dripping.
F4: Condenser fan stop temperature
This is used to select the temperature at which the condenser fans should be switched OFF. If setting the auxiliary relay as the
condenser fan output (see parameter H1), this will enable adjustments according to the diagram in Figure 7.p:
When the compressor is fi rst started, the fans are switched ON at F4 + 0.2 degrees to compensate for rapid temperature increases
that are not easy for the probe to follow.
After this, control is performed normally, i.e.:
• on: F4 + F5