User manual

39
ENG
MPXPRO - + 0300055EN rel. 1.3 07/03/13
Staggered defrosts
The function is used to perform a series of daily defrosts by setting just
the fi rst using parameter td1 and then indicating the number of defrosts
per day using parameter d1S. The controller automatically schedules
all the defrosts to be performed at regular intervals over the 24 hours
following the event defi ned by td1. The same applies to td2 and dS2.
Par Description Def Min Max UoM
d1S Number of daily defrosts (td1)
0 = Disabled
1 = 24 hours 0 mins 8 = 3 hours 0 mins
2 = 12 hours 0 mins 9 = 2 hours 40 mins
3 = 8 hours 0 mins 10 = 2 hours 24 mins
4 = 6 hours 0 mins 11 = 2 hours 11 mins
5 = 4 hours 48 mins 12 = 2 hours 0 mins
6 = 4 hours 0 mins 13 = 1 hour 0 mins
7 = 3 hours 26 mins 14 = 30 mins
0 0 14 -
d2S Number of daily defrosts (td2)
see d1S
0 0 14 -
Tab. 5.u
Remember that sub-parameter “d_” of td1(td2) defi nes the defrost day,
as follows:
d_ = Defrost– day
0 = event disabled 9 = Monday to Saturday
1 to 7 = Monday to Sunday 10 = Saturday to Sunday
8 = Monday to Friday 11 = every day
Note:
• if event td1 includes a series of days, the programming always ends
at 24.00 on the last day. If event td1 includes one day only, the
programming ends at 24.00 on the same day;
• if both td1 and td2 are set, when the defrost events overlap, only the
sequence of defrost that start fi rst are performed.
5.1 5.7 Evaporator fans
The evaporator fans can be managed, if required, according to
the temperature measured by the defrost and control probes. The
deactivation threshold is equal to the value of parameter F1, and the
hysteresis is equal to the value of Frd.
Note: during the dripping waiting time (in the event of network
defrosts), and during the dripping time and post-dripping time, if
set, the evaporator fans are always off .
Fixed speed fans
Below are the parameters involved in managing fi xed speed fans, related
by default to relay 4, and a example of the trend based on the diff erence
between the evaporator temperature and the value of the virtual probe
(F0=1). If the double thermostat function is enabled, activation is based
on the diff erence between the evaporator temperature and the outlet
probe temperature.
If F0=2, activation depends solely on the evaporator probe temperature.
Par. Description Def Min Max UoM
F0 Evaporator fan management
0 = always on
1 = activation based on Sd – Sv
(or Sd - Sm in double thermostat)
2 = activation based on Sd
002-
F1 Evaporator fan activation threshold
(only if F0 =1 or 2)
-5.0 -50.0 50.0 °C/°F
Frd Fan activation diff erential (including
variable speed)
2 0.15 20 °C/°F
Tab. 5.v
Sd-Sv
t
t
F0 = 1
F1
F1-Frd
ON
OFF
FAN
Sd
t
t
F0 = 2
F1
F1-Frd
ON
OFF
FAN
Fig. 5.o
Key
Sd Evaporator probe Frd Diff erential
Sv Virtual probe t Time
F1 Fan activation threshold FAN Evaporator fans
The fan can be turned off in the following situations:
• when the compressor is off (parameter F2);
• during the defrost (parameter F3).
During the dripping period (parameter dd > 0) and the post-dripping
period (parameter Fd > 0) the evaporator fans are always off .
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 defrost (parameter F3).
Par. Description Def Min Max UoM
F2 Evaporator fans with compressor off
0 = see F0; 1 = always off
101-
F3 Evaporator fans during defrost
0 = on; 1= off
101-
dd Dripping time after defrost (fans off )
0 = no dripping
2 0 15 min
Fd Post dripping time after defrost (fans
off with control active)
1 0 15 min
Tab. 5.w
Variable speed fans
The installation of variable speed fans may be useful in optimising energy
consumption. In this case, the fans are powered by the mains, while the
control signal may come from:
• output PWM2 on the main board;
• a 0 to 10 Vdc output on the driver board.
The maximum and minimum fan speed can be set using advanced
parameters F6 and F7.
If using the fan speed controller, F5 represents the temperature below
which the fans are activated. There is a fi xed hysteresis of 1°C for
deactivation.
Par. Description Def Min Max UoM
F5 Evaporator fan cut-off temperature (hyste-
resis 1°C)
50 F1 50 °C/°F
Tab. 5.x