The first defrost after swiching on can be set by par.
“d.Sd”
This allows to perform the first defrost to a different interval from
"d.di." time.
If it is desired that to every instrument power on a defrost cycle is
realized (as long as the conditions set in the parameters “d.tS” and
"d.tE" apply) program the par. "d.Sd" = oF.
This allows the evaporator to be permanently defrosted, even when
frequent interruptions to power supply occur that may cause the
cancellation of the various defrosting cycles.
Instead
if is desired all defrost to the same interval program "d.Sd"
= "d.di."
Automatic defrost function by interval is disable when “d.di” = oF.
“Dynamic Defrost Intervals System”
.
If “d.dd” = 0 the Dynamic defrost is disable.
Note:
For this function is necessary to use the evaporator probe,
program “d.dC” = rt, ct or cS and set “d.dd” = any value (not 0)
This mode allows to dynamically reduce in progress the defrost
interval counting ("d.di" or "d.Sd" if is the first defrost), anticipating
so the execution of a defrost when it was necessary, in order to an
algorithm that allows to notice a decrease performances of
refrigerator thermal exchange.
Besides it maintains activates the defrost by evaporator temperatu-
re mode that it allows a further possibility of control of the defrost in
order to notice a decrease performances of refrigerator thermal
exchange.
The algorithm allows to esteem a reduction of thermal exchange in
base to the increase of the difference of temperature between Pr1
(controlled temperature) and evaporator (“EP” probe) that is memo-
rized by the instrument in proximity of the Set Point.
The advantage of the “Dynamic Defrost Interval” is the possibility to
program a defrost interval time more longer than normal.
The instrument will have the possibility to anticipate the defrost if
necessary or to start the cycle after the programmed time.
If the system results set correctly is possible to to avoid many non
necessary defrosting cycles (and therefore to obtain an energy sa-
ving) that could instead happens in the normal operation when, to
guarantee with greater certainty the system efficency , the defrost
interval is programmed at a too low time.
Pr1
Temp.
time
EP
SP
r.d
off
ON
Cool
(ot)
SP+r.d
DT0
DT1
1 °
DT2
DT3
ON
ON
ON
off
off
d.tE
d.di / d.Sd
Defrost
(dF)
Phase
0
1
2
3
time to defrost Ph. 0, 1
time to defrost Ph. 2
time to defrost Ph. 3
Defrost
d.tS
Example “dynamic defrost intervals system” with a reduction “d.dd”
= 40 % and end defrost by temperature.
By par.
: “d.dd”
- DEFROST INTERVAL PERCENTAGE
REDUCTION is possible to establish the percentage of reduction of
the remaining time to start defrost when the conditions for the
reduction happen.
If par. "d.dd" = 100% at the first increase of the memorized
difference of temperature between cell (Pr1) and evaporator (> 1 °)
a defrost start immediately
For correct functioning the instrument needs a first reference value
of the temperature difference between cell and evaporator.
Every variation of the value of the Active Set Point, of the
differential "r.d", the start of a continuous cycle or the a defrost
execution delete this reference value and any reduction will be
performed until the acquisition of a new reference value.
- Defrost by evaporator temperature
The instrument starts a defrost cycle when the evaporator
temperature (“EP” probe) goes below the
“d.tF”
programmed
temperature for
“d.St”
programmed time.
This system can be used in heat pump defrost system (in this case
the defrosting intervals are usually disabled) or to guarantee a
defrost if the evaporator reaches very low temperatures that
normally result symptomatic of a bad thermal exchange in
comparison to the normal working conditions.
If “d.tF” = -99.9 the function is disable.
The function is active in all modes of defrost operation ("d.dC" = cL,
rt, ct, cS).
- Defrost by continuous compressor running time
The instrument start a defrost cycle when the compressor is turned
on continuously for the time
"d.cd”.
This function is used because the continuous operation of the com-
pressor for an extended period is usually symptomatic of a bad
thermal exchange in comparison to the normal working conditions.
If "d.cd" = oF the function is disabled.
The function is active in all modes of defrost operation ("d.dC" = cL,
rt, ct, cS).
4.8.2- MANUAL DEFROST
To start up a manual defrosting cycle, press the key UP/DEFROST
when it is not in programming mode and keep it pressed for about
5 seconds after which, if the conditions are correct, the led Defrost
will light up and the instrument will carry out a defrosting cycle.
To stop a defrosting cycle, press the key UP/DEFROST during a
defrost cycle and keep it pressed for about 5 sec.
4.8.3 - DEFROST ENDS
By using par.
"d.PE"
you can determine whether the duration of
the defrost cycle can be by time or when a temperature is reached.
In the event that "d.PE" = oF or the evaporator probe is not used
(or is not available, measure the selected temperature) or still use
the defrost thermostat (par. "d.dt" = Et) the duration of the cycle is
set by par.
"d.dE"
If instead the evaporator probe is used the defrost cycle end when
the temperature measured by the evaporator probe (if “d.PE” = EP)
or the temperature measured by the Pr1 probe (if “d.PE” = P1)
exceeds the temperature set in the parameter
“d.tE”.
If this temperature is not reached in the time set in the parameter
“d.dE”, defrosting is interrupted.
If the temperature measured by the probe is higher than the
temperature set in the parameter "d.tS" and “d.tE” the defrosting is
inhibited.
d.di
Temp.
dF
d.di
off
d.tS
d.tE
ON
A
off
EP
d.di
ON
d.dE
B
(NO defrost)
d.di
off
C
time
Examples:
defrosting A ends due to reaching of temperature “dtE”,
defrosting B ends at the end of the “d.dE” time as the temperature
“d.tE” is not reached, defrosting C does not take place as the
temperature is higher than “d.tS”.
d .d i
d .tE
d .tS
d F
o ff
O N
o ff
T e m p .
E P
1 °
tim e
d .d E
d .d i
O N
O N
ASCON TECNOLOGIC - Y33
- OPERATING INSTRUCTIONS - Vr. 01 - 04/16 - ISTR-MY33-ENG01 - PAG. 8