Carel ir33+ small wide User Manual page 27

Key
St Set point rd Diff erential
CMP Compressor FAN Fan
Sv Virtual probe r4 Automatic night-time set point variation
Note: if one of the auxiliary outputs is used to manage the light,
lowering the curtain automatically switches the light off , while raising it
switches the light on.
8 = Low pressure switch input for pump down
See par. 6.4. Setting "A4"=8 manages the low pressure switch. The low
pressure alarm "LP" is signalled when the low pressure switch is activated:
•
during normal control (c7=0) with the compressor on, or alternatively
•
with pump-down function confi gured (c7 >0), if the pump down valve
is open and the compressor is on.
The low pressure alarm signal is delayed by the time set for parameter
"A7". The low pressure alarm "LP" stops the compressor.
ir33+
ON
CMP
OFF
ON
Pressure
switch
OFF
HIGH
Pump down
valve
LOW
ON
LP
Alarm
OFF
Key
CMP Compressor Pump down valve Pump down valve
Pressure Switch Pressure LP alarm
switch
t Time A7
Note: this parameter, together with c7, c8, c9 and H1, H5, allows
management of the "pump-down" algorithm (see par 6.3).
9 = Door switch with fan off only
Same as for option "A4"=5, with the diff erence being that when opening
the door only the evaporator fan is switched off .


t
A7
Fig. 5.e
Low pressure alarm
Alarm signal delay
10 = Direct/reverse operation
Important: when A4 = 10, the status of digital input has priority
over the setting of parameter r3 (direct/reverse operating mode).
When the contact is open, the controller operates in "direct" mode
(cooling), when the contact is closed, in "reverse" mode (heating). A switch
can therefore be connected to select heating or cooling operation.
r3 = 0, 1, 2
CMP/FAN
DI OPEN
ON
OFF
rd Sv
St
DIRECT
Key
St Set point
rd Diff erential
FAN Fan
11 = Light sensor
The digital input is used to read a light sensor (P/N PSOPZLHT00, actually an
analogue input, from which a digital signal is taken using the parameter or
threshold of the light sensor).
The light sensor can be located:
•
in the door jamb (ref. A);
•
inside the cold room or cabinet (ref. B).
Par. Description
AF Light sensor OFF time
0 Sensor in the door jamb
> 0 Sensor inside the cold room or cabinet
A (AF=0)
Light sensor The sensor signals
signal the opening and
closing of the door
Inside light: on With the door open If the sensor detects light
Inside light: off With the door
closed, minimum off
time of 5 s, to avoid
rapid, successive
impulses of the light
relay
27
ENG
r3 = 0, 1, 2
CMP/FAN
DI CLOSED
ON
OFF
Sv
rd
St
REVERSE
Fig. 5.f
Sv Virtual probe
CMP Compressor
Def Min Max UOM
0 0 250 s
Tab. 5.h
B
A
Fig. 5.g
B (AF = 1)
The sensor signals the opening of the
door and detects light inside the cabi-
net/cold room. The sensor also signals
closing of the door
Closing of the door is measured by
time, as the inside light will illuminate
the sensor. After the time AF (>0) the
inside light is switched off for 5 secon-
ds. If the light sensor signals darkness,
the door must be closed and the light
will therefore remain off ;
if it signals light: the door is open and
the light will be switched on again.
Tab. 5.i
ir33plus +0300028EN rel. 1.1 - 05.05.2017