Order No.: 900220.020
V2.24
8/11
cooling performance.
d0: Defrosting interval
The defrosting interval defines the time, after which
a defrosting process is started. With the beginning of
the defrosting process, the defrosting interval starts
anew, which results in periodic defrosting in firm
intervals.
Defrosting can also be started by pressing the key
"manual defrosting" for at least 3 seconds. This
automatically restarts the defrosting interval.
After switching-on cooling, the controller immediately
initiates cooling and starts the first defrosting
process after this interval.
d1: Defrosting mode
This parameter determines whether defrosting is
effected by an electrical heating coil (d1=0) or by
means of hot gas (d1=1).
d2: Defrosting temperature
The defrosting process is terminated when the
evaporator has reached the adjusted temperature.
(Always provide good thermal contact between
evaporator sensors and lamellas).
In case that defrosting takes too long, the time limit
set in "d3" will come into effect.
d3: Defrosting time limit
Here the maximal defrosting time can be adjusted.
According to this time frame, defrosting is terminated
even if the evaporator is not warm enough to be ice-
free.
d6: Indication of the refrigerating chamber
temperature during defrosting
It is to be assumed that the refrigerating chamber
temperature slightly rises during the defrosting
process. d6=0 indicates the actual refrigerating
chamber temperature during the defrosting process.
d6=1 indicates the temperature determined just
before the start of defrosting until the setpoint of the
refrigerating chamber is reached again after the
defrosting process is completed. Thus, an irritation
of the operator during defrosting can be avoided. In
the case of emergency, the display flashes and the
actual temperature of the refrigerating chamber is
indicated.
d7: Drainage time
Completed defrosting is immediately followed by a
drainage period, in order to let the evaporator drip
off. During drainage time, the exits compressor and
ventilator are switched off.
A0: Switching hysteresis for alarm
The hysteresis of the alarm contact is
asymmetrically, set downward at the maximum
alarm value upward at the minimum alarm value.
A1/A2: Minimum/maximum limit values
The limit values serve for monitoring of the
refrigerating chamber temperature. They are
relative, i.e. going along with the setpoint S1 of the
refrigerating chamber. Alarm is released when
exceeding maximum limit value or when falling
below the minimum limit value:
The actual value display flashes, the buzzer (if
available) goes off intermittently and the actual
temperature of sensor F1 is indicated (if there is no
sensor error).
At A1=0 or A2=0 the respective limit value alarm is
inactive.
The buzzer can be turned off with the DOWN key,
the display continues flashing until the alarm is
turned off.
A3: Alarm suppression time after “cooling on”
After switching cooling on, an alarm is suppressed
for the adjusted time, i.e. the refrigerant plant can
get to work temperature without releasing alarm.
A6: Alarm suppression time after temperature
alarm
If the refrigerating chamber temperature exceeds the
limit values adjusted at A1, A2, normally a
temperature alarm should be released.
With the suppression time set at A6 the alarm
release can be delayed.
A7: Alarm suppression time after defrosting
Temperature alarm is avoided for the adjusted time
after defrosting, in order to enable the plant to get
back to the normal operating conditions (see A1,
A2).
A9: Switching sense alarm exit
Depending on application, the alarm exit requires a
normally-closed or a normally-open contact. At
setting A9=1 the relay tightens in normal operation
and opens in the case of emergency. That way also
a voltage failure of the controller can be detected
(relay dead = alarm) for an external alarm chain.
F4: Defrosting behaviour
At F4=0 the ventilator is switched off during
defrosting.
At F4=1 the ventilator continues to run also during
defrosting (normal cooling range above 0°C).
F5: Ventilator deceleration time after defrosting
Following drainage time d7, start of the ventilator
can be delayed until the evaporator has sufficiently
cold air again. If the ventilator started immediately,
the warm air resulting from the defrosting process
would probably be blown into the refrigerating
chamber.
Содержание ST501-KU3KA.12P
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