Carel + 0300028EN, User Manual, Page: 42 / 60

14
ENG
ir33+ VCC +040000058 - rel. 1.2 - 15.02.2018
3.1.6 Pull down
The controller activates an automatic pull down procedure whenever the refrigeration unit temperature
exceeds the high temperature threshold
AH . The Pull Down procedure ends when the refrigeration unit
temperature reaches the set point St . The maximum Pull Down time is set for parameter cPd . During a Pull
Down cycle, defrost calls are ignored and remain in standby.
Code Parameter UOM Dis. Def. Max Min
AH AL = Low temperature alarm threshold °C/°F C -14 50.0 -50.0
cPd Compressor maximum pull down time h C 1 240 0
Tab. 3.e
3.1.7 Evaporator fan
The evaporator fan is managed based on parameters F0/F1/F2/F3 , in the same way as for standard control.
The fan is also managed as standard with the defrost water drain heating function. During the dripping time
dd and the post-dripping time Fd , the fan remains off .
Code Parameter UOM Dis. Def. Max Min
F0 Evaporator fan management - C 0 2 0
F1 Fan activation temperature (only if F0 = 1 or 2) °C/°F C 5 200 -50
F2 Evap. fans with compressor off 0 = see F0; 1 = Always off - C 1 1 0
F3 Evaporator fans during the defrost: 0/1=on/off
dd Dripping time after defrost (fans off ) min C 2 15 0
Fd Post-dripping time after defrost (defrost water drain heating remains
active during this time/fans off with control active) min. C 3 15 0
Tab. 3.f
3.1.8 Continuous cycle
When the continuous cycle is activated the compressor is started (if off , otherwise it stays on). In this case there
is no active temperature control. The compressor runs to the speed set for parameter
cMf . The continuous
cycle remains active until reaching the low temperature alarm threshold (parameter AL ) or when the set time
has elapsed (parameter cc).
3.1.9 Neutral zone and reverse mode
Compressor confi guration with neutral zone and AUX relay as heater in reverse mode.
The AUX relay must be confi gured as a heater by setting
H1=11 . The compressor starts working when St +
rn/2 + rd , as described in the following diagram. To activate the AUX heater H1=11 , the compressor must be
off and the set point reached.
Note the following:
•
The compressor stops when T< St and the time set for cct has elapsed.
•
If cct is set to 0 , the compressor stops immediately when the temp. T reaches the set point St ”.
•
If cct is set to 255 , the compressor never stops and the AUX heater is disabled.
ON
OFF
CMP
rr rn/2 rn/2
AUX
rd
St
Fig. 3.f