Carel MPXone - Page 60

60
ENG
mpxone +0300086EN rel. 2.2 - 13.11.2023
Functions
5.4 Fan management
5.4.1 Evaporator fans
The evaporator fans can be managed, if required, according to the temperature measured by any two of the probes connected
to the MPXone controller. The deactivation threshold is equal to the value of parameter F1, and the hysteresis is equal to the
value of Frd.
Notice: during the dripping waiting time (in the event of network defrosts), and during the dripping time, the evaporator fans
are always off, while during the post-dripping time, if set, evaporator fan operation depends on the setting of par. Fpd.
Fixed-speed fans
The parameters used to manage fixed-speed fans are shown below (see the connection diagram).
MPXone manages the evaporator fans as follows:
• F0 = 0 always on;
• F0 = 1 off when the difference between the two probe values Sa and Sb (defined by parameters FSa and FSb) exceeds the
threshold set for parameter F1;
• F0 = 2 on/off based on Sa probe, defined by parameter FSa.
Code Description Def Min Max UOM User User terminal
F0 Evaporator fan management
0 = always on
1 = activation based on Sa - Sb (see FSa and FSb)
2 = activation based on Sa (Sa = first probe, Sb = second probe)
3 = fans ON with door closed (dip configured)
002- SYES
F1 Evaporator fan activation threshold (only if F0 = 1 or 2) -5 -50 50 °C/°F S YES
Frd Fan activation differential (including variable speed) 2 0.1 20 °C/°F S YES
FSa First fan control probe
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)
2 0 14 - M NO
FSb Second fan control probe - see FSa 13 0 14 - M NO
300086_055_R01
S
a
-S
b
t
t
F0 = 1
F1
F1-Frd
ON
OFF
FAN
300086_072_R01
S
a
t
t
F0 = 2
F1
F1-Frd
ON
OFF
FAN
Fig. 5.x Fig. 5.y
Ref. Description
Sa Probe set by parameter FSa
Sb Probe set by parameter FSb
F1 Fan activation threshold
Ref. Description
Frd Differential
t time
FAN Evaporator fans
The fans can be turned off in the following situations:
• when the solenoid valve is deactivated (parameter F2);
• during defrosts (parameter F3).
During the dripping time (parameter dd > 0) the fans are off, and during the post-dripping time (parameter Fd > 0), the evapo-
rator fans are on or off depending on the value of parameter Fpd.
This is useful to allow the evaporator to return to temperature after defrosting, thus avoiding blowing warm hot and moist air
into the refrigerated environment.
The evaporator fans can be forced on during control (parameter F2) and during defrosts (parameters F0 and F3).