SZ 1598030250 XR02CX RWA GB r1.2 29.08.2013.doc XR02CX 1/2
DIGITAL CONTROLLER
XR02CX
1GENERAL WARNINGS................................................................................................................................... 1
2GENERAL DESCRIPTION.............................................................................................................................. 1
3REGULATION.................................................................................................................................................. 1
4DEFROST ........................................................................................................................................................ 1
5FRONT PANEL COMMANDS ......................................................................................................................... 1
6PARAMETERS ................................................................................................................................................ 1
7INSTALLATION AND MOUNTING.................................................................................................................. 2
8ELECTRICAL CONNECTIONS....................................................................................................................... 2
9HOW TO USE THE HOT KEY ........................................................................................................................ 2
10 ALARM SIGNALLING...................................................................................................................................... 2
11 TECHNICAL DATA.......................................................................................................................................... 2
12 CONNECTIONS............................................................................................................................................... 2
13 DEFAULT SETTING VALUES ........................................................................................................................ 2
1 GENERAL WARNINGS
1.1 PLEASE READ BEFORE USING THIS MANUAL
This manual is part of the product and should be kept near the instrument for easy and quick
reference.
The instrument shall not be used for purposes different from those described hereunder. It cannot be
used as a safety device.
Check the application limits before proceeding.
1.2 SAFETY PRECAUTIONS
Check the supply voltage is correct before connecting the instrument.
Do not expose to water or moisture: use the controller only within the operating limits avoiding sudden
temperature changes with high atmospheric humidity to prevent formation of condensation
Warning: disconnect all electrical connections before any kind of maintenance.
Fit the probe where it is not accessible by the End User. The instrument must not be opened.
In case of failure or faulty operation send the instrument back to the distributor or to “Dixell S.r.l.” (see
address) with a detailed description of the fault.
Consider the maximum current which can be applied to each relay (see Technical Data).
Ensure that the wires for probes, loads and the power supply are separated and far enough from each
other, without crossing or intertwining.
In case of applications in industrial environments, the use of mains filters (our mod. FT1) in parallel
with inductive loads could be useful.
Dixell Srl reserves the right to change the composition of its products, even without notice, ensuring
the same and unchanged functionality.
2 GENERAL DESCRIPTION
Model XR02CX, format 32 x 74 x 50 mm, is a digital thermostat, with off cycle defrost, designed for
refrigeration applications at normal temperature. It provides a relay output to drive the compressor. It is also
provided with 2 NTC probe input. The instrument is fully configurable through special parameters that can be
easily programmed through the keyboard or the by HOT-KEY.
3 REGULATION
3.1 THE REGULATION OUTPUT
The regulation is performed according to
the temperature measured by the
thermostat probe with a positive differential
from the set point: if the temperature
increases and reaches set point plus
differential the compressor is started and
then turned off when the temperature
reaches the set point value again.
In case of fault in the thermostat probe the start and stop of the compressor are timed through parameters CY
and Cn.
4 DEFROST
Defrost is performed through a simple stop of the compressor. Parameter id controls the interval
between defrost cycles, while its length is controlled by parameter Md.
5 FRONT PANEL COMMANDS
To display target set point, in programming mode it selects a parameter or confirm an
operation
(DEF) To start a manual defrost
(UP) In programming mode it browses the parameter codes or increases the displayed
value
AUX
(DOWN) In programming mode it browses the parameter codes or decreases the
displayed value
KEYS COMBINATION
To lock or unlock the keyboard
To enter in programming mode
To return to room temperature display
LED MODE MEANING
On Compressore enabled
Flashing Anti short cycle delay enabled (AC parameter)
On Defrost in progress
Flashing Dripping in progress
On Measurement unit
Flashing Programming mode
On Measurement unit
Flashing Programming mode
5.1 HOW TO SEE THE SET POINT
1. Push and immediately release the SET key, the set point will be showed;
2. Push and immediately release the SET key or wait about 5 sec to return to normal visualisation.
5.2 HOW TO CHANGE THE SETPOINT
1. Push the SET key for more than 2 sec to change the Set point value;
2. The value of the set point will be displayed and the “°C” or “°F” LED starts blinking;
3. To change the Set value, push the o or n arrows within 10 sec.
4. To memorise the new set point value push the SET key again or wait for 10 sec.
5.3 HOW TO START A MANUAL DEFROST
Push the DEF key for more than 2 sec and a manual defrost will start.
5.4 HOW TO CHANGE A PARAMETER VALUE
To change the parameter’s, value operate as follows:
1. Enter the Programming mode by pressing the SET+DOWN keys for 3 sec (“°C” or “°F”LED starts
blinking).
2. Select the required parameter. Press the SET key to display its value
3. Use UP or DOWN to change its value.
4. Press SET to store the new value and move to the following parameter.
To exit: press SET+UP buttons or wait for 15 sec without pressing any key.
NOTE: the set value is stored even when the procedure is exited by waiting the time-out to expire.
5.5 TO LOCK THE KEYBOARD
1. Keep pressed for more than 3 sec the UP and DOWN keys.
2. The “OF” message will be displayed and the keyboard will be locked. If a key is pressed more
than 3 sec the “OF” message will be displayed.
5.6 TO UNLOCK THE KEYBOARD
Keep pressed together for more than 3 sec the UP and DOWN keys till the “on”message will be
displayed.
6 PARAMETERS
REGULATION
Hy Differential: (0.1 to 25°C; 1 to 45°F) differential for set point. Compressor Cut IN is SET POINT +
differential (Hy). Compressor Cut OUT is when the temperature reaches the set point.
LS Minimum SET POINT: (-55°C to SET; -67°F to SET) sets the minimum value for the set point.
US Maximum SET POINT: (SET to 99°C; SET to 99°F) set the maximum value for set point.
ot First probe calibration: (-9.9 to 9.9°C; -17 to 17°F) allows to adjust possible offset of the first probe.
P2 Evaporator probe presence: n= not present; y= the defrost stops by temperature.
oE Second probe calibration: (-9.9 to 9.9°C; -17 to 17°F) allows to adjust possible offset of the second
probe.
F5 Filter probe enabling: (nu; AL; do) set the field of action of the internal measurement filter. nu=not
used; AL=the filter will always works on all probes; do=the filter will only works on all probes for 30
sec after opening of the door.
od Outputs activation delay at start up: (0 to 99min) this function is enabled at the initial start up of the
instrument and inhibits any output activation for the period of time set in the parameter.
AC Anti-short cycle delay: (0 to 50 min) minimum interval between the compressor stop and the
following restart.
Cy Compressor ON time with faulty probe: (0 to 99min) time during which the compressor is active in
case of faulty thermostat probe. With Cy=0 compressor is always OFF.
Cn Compressor OFF time with faulty probe: (0 to 99min) time during which the compressor is OFF in
case of faulty thermostat probe. With Cn=0 compressor is always active.
DISPLAY
CF Measurement unit: (°C; °F) °C =Celsius; °F =Fahrenheit. WARNING: When the
measurement unit is changed the SET point and the values of the parameters Hy, LS, US, oE,
o1, AU, AL have to be checked and modified if necessary.
rE Resolution (only for °C): (dE; in) dE= decimal between -9.9 and 9.9°C; in= integer.
Ld Default display: (P1; P2) P1= thermostat probe; P2= evaporator probe.
dy Display delay: (0 to 15min) when the temperature increases, the display is updated of 1°C or
1°F after this time.
DEFROST
dE Defrost termination temperature: (-55 to 50°C; -67 to 99°F) if P2=Y it sets the temperature
measured by the evaporator probe, which causes the end of defrost.
id Interval between defrost cycles: (0 to 99min) Determines the time intervals between two
consecutives cycles of defrost.
Md Maximum length for defrost: (0 to 99min, 0 means no defrost) when P2=n, (not evaporator
probe: timed defrost) it sets the defrost duration, when P2 = y (defrost end based on
temperature) it sets the maximum length for defrost.
dF Display during defrost: (rt; it; SP; dF) rt= real temperature; it= start defrost temperature;
SP= SET-POINT; dF= label dF.
ALARMS
AU Maximum temperature alarm: (AL to 99°C; AL to 99°F) when this temperature is reached
the alarm is enabled, after the “Ad” delay time.
AL Minimum temperature alarm: (-55°C to AU; -67°F to AU) when this temperature is reached
the alarm is enabled, after the Ad delay time.
Ad Temperature alarm delay: (0 to 99min) time interval between the detection of an alarm
condition and alarm signalling.
