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USER MANUAL – Release 1.2 of 01/01/2010
Page 132 of 191
Version: 02/03/2010
49.1 DESCRIPTION OF DEFROST PARAMETERS
dF01
Determines the type of defrost mode
0 = Defrost disabled
1 = Defrost in temperature/pressure. The dF09 defrost interval count takes place when the temperature
drops below the dF02 set. The defrost cycle ends due to temperature/pressure.
2 = Timed defrost. The dF09 defrost delay time count takes place when the temperature/pressure drops
below the dF02 set (see the start probe par. dF28). The defrost cycle ends due to maximum time dF05.
3 = Defrost due to external contact. The dF09 defrost delay time count takes place when the
temperature/pressure drops below the dF02 set (see the start probe par. dF28). The defrost cycle ends with
the digital input active.
dF02
Count start temperature/pressure that determines the request delay between two successive defrost
cycles.
Allows to set a temperature/pressure set below which the count starts.
dF03
Defrost end temperature/pressure
.
Allows to set a temperature/pressure set that determines the end of the defrost cycle.
dF04
Defrost minimum duration
Allows to set a time that determines the minimum duration of the defrost cycle once it has started (even if the
end situations have been exceeded).
dF05
Maximum duration of the defrost cycle
Allows to set a maximum time for the defrost cycle if dF01 = 2 determines the end. In the other cases it
determines the maximum duration.
dF06
delay time between the successive defrost between two circuits
on expiry of the interval time dF09
relative to the circuit requested. The time set in par. dF06 must have passed before entry into defrost mode
Active if a unit is configured with more than one cooling circuit.
dF07
Stand-by time before defrost (the compressor LED flashes during this phase)
When the time set by dF09 has passed, before true activation of the defrost cycle, the device stops the
compressor for the time dF07.
With compressor stop after a time equal to the half of the dF07 time set, the 4-way valve rotates.
This stand-by allows balancing of the pressures inside the cooling circuit.
When all of the dF07 time has passed the compressor re-starts and defrost takes place.
The compressor protection times are not respected with this procedure, therefore compressor switch-off and
relative switch-on again are immediate.
If dF07 = 0 the compressor is not stopped and the reverse valve turns immediately.
dF08
Stand-by time after defrost (the compressor LED flashes during this phase)
at the end of the defrost cycle the device stops the compressor for a time dF08.
With compressor stop after a time equal to the half of the dF08 time set, the 4-way valve rotates.
This stand-by allows balancing of the pressures inside the cooling circuit and any dripping of the external
coil.
When all of the dF08 set time has passed, the unit starts to function in heating mode.
The compressor protection times are not respected with this procedure, therefore compressor switch-off and
relative switch-on again are immediate.
If dF08 = 0 the compressor is not stopped and the reverse valve turns immediately.
dF09
defrost interval time
The count decreases if the temperature/pressure detected by the condensation/evaporation probe is below
the dF02 set
The timer is reloaded at dF09
if
there is a power cut or after having performed the defrost cycle or on
changing the working mode.
The timer is interrupted
if
the compressor switches off or if
the temperature/pressure detected by the probe
exceeds dF02
dF10
Start temperature set of circuit n° 1 defrost cycle.
Allows to set a temperature set below which the defrost cycle takes place.
At the end of the dF09 time count the device sees the temperature of the circuit n° 1 combined defrost NTC
probe. If the temperature is below the dF10 set, the defrost procedure is performed otherwise it continues to
function in heating mode. As soon as the temperature drops below the set, it performs defrost.
dF11
Start temperature set of circuit n° 2 defrost cycle
.
Allows to set a temperature set below which the defrost cycle takes place.
At the end of the dF09 time count the device sees the temperature of the circuit n° 2 combined defrost NTC
probe. If the temperature is below the dF11 set, the defrost procedure is performed otherwise it continues to
function in heating mode. As soon as the temperature drops below the set, it performs defrost.
dF12
Start temperature set of circuit n° 3 defrost cycle
.
Allows to set a temperature set below which the defrost cycle takes place.
