52
ENG
mpxone +0300086EN rel. 2.2 - 13.11.2023
Functions
End defrost in advance due to high temperature
MPXone can terminate a defrost in advance if the value read by a configurable probe exceeds a certain maximum value. This is
especially useful in cases where the defrost probe has not been positioned correctly, thus preventing, above all for heater de-
frosts, the temperature inside the cabinet or cold room from reaching an excessively high value. If the defrost ends in advance,
the controller shows the corresponding signal (dEA) on the display, which will be cleared only when the next defrost ends
correctly.
Code Description Def Min Max UOM User User terminal
dET Assign probe for end defrost in advance
0 Not configured
1 Outlet (Sm)
2 Defrost (Sd)
3 Intake (Sr)
4 Superheated gas (tGS)
5 Saturated evaporation pressure (PEu)
6 Defrost 2 (Sd2)
7 Auxiliary temperature 1 (Saux1)
8 Auxiliary temperature 2 (Saux2)
9 Ambient (SA)
10 Ambient humidity (SU)
11 Glass temperature (Svt)
12 Dew point (SdP)
13 Virtual probe (Sv)
14 Saturated evaporation temperature (tEu)
0014- SNO
dEP Temperature threshold for end defrost in advance 50 -99.9 99.9 °C S NO
At the end of the defrost, the dripping phase can be enabled (if dd>0), during which the solenoid valve is closed and the fans are
off. Subsequently, the post-dripping phase can be enabled (if Fd>0), during which control resumes and the fans operate based
on the setting of parameter Fpd. The type of display on user terminal and the remote display during the defrost can be selected
by setting parameter d6.
Notice: high temperature alarms can be disabled after defrosting by setting par. d8.
Code Description Def Min Max UOM User User terminal
d0 Type of defrost
0 heater by temperature 3 hot gas by time
1 hot gas by temperature 4 heater by time with
temperature control
2 heater by time
004- SYES
dt1 End defrost temperature (read by Sd) 8 -50 50 °C/°F S YES
dP1 Maximum defrost duration 45 1 240 min S YES
d6 Display on terminals during defrost
0 = temperature alternating with ‘dEF’
1 = freeze display
2 = ‘dEF’
102- UNO
d8 Bypass high temperature alarm time after defrost 30 1 240 min S NO
F3 Evaporator fan status during defrost 0 = see F0, 1 = off 1 0 1 - S F3
Fd Post-dripping time after defrost (fans off with control active) 2 0 15 min S NO
Fpd Evaporator fans during post-dripping
0=On, 1=Off
001- 0NO
Below is the trend of the defrost output based on the setting of parameter d0.
300086_054_R01
t
dP1
dt1
Sd
OFF
DEF
d0=4
d0=2,3
d0=0,1
DEF
DEF
ON
OFF
ON
OFF
ON
t
t
t
Ref. Description
t Time
dt1 End defrost temperature
dP1 Maximum defrost duration
Sd Defrost probe
DEF Defrost
Fig. 5.p
The heater defrost by time with temperature control (d0=4) activates the defrost output only if the evaporator temperature (Sd)
is less than the value of parameter dt1, and ends after the time defined by dP1. This function is useful for energy saving and to
prevent excessive temperatures on the evaporator.
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