Emerson Dixell XR44CX Installing And Operating Instructions

Digital controller with defrost and fans management
XR44CX
1. GENERAL WARNING
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 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.
2. GENERAL DESCRIPTION
Model XR44CX, format 32 x 74 mm, is microprocessor based controller, suitable for applications on
low temperature refrigerating units. It has four relay outputs to control compressor 1 and 2, defrost 1
and 2, which can be either electrical or reverse cycle (hot gas). It is also provided with up to three
NTC or PTC probe inputs, the first one for temperature control, the second and third one, to be
located onto the evaporator, to control the defrost termination temperature on the evaporator 1 and 2.
It allows to program the controller by means the HOT KEY programming keyboard.
3. CONTROLLING LOADS
3.1 COMPRESSOR
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 "COn" and "COF".
3.2 2 ND COMPRESSOR MANAGEMENT
The relay of the second compressor is activated in parallel with the relay of the first compressor, with
a possible delay set in the AC1 parameter. Both the compressors are switched off at the same time.
3.3 DEFROST
Two defrost modes are available through the "tdF" parameter: defrost through electrical heater (tdF =
EL) and hot gas defrost (tdF = in). Other parameters are used to control the interval between
defrost cycles (IdF), its maximum length (MdF and MdS) and two defrost modes: timed or controlled
by the evaporator's probe (P2P and P3P).
At the end of defrost dripping time is started, its length is set in the Fdt parameter. With Fdt =0 the
dripping time is disabled.
This instrument can manage up to 2 evaporators; the XR44CX waits till the defrost termination on
both evaporators before restart with the normal temperature control.
4. 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): To see the max. stored temperature; in programming mode it browses the parameter
codes or increases the displayed value.
(DOWN) To see the min stored temperature; in programming mode it browses the parameter
codes or decreases the displayed value.
To switch the instrument off and on.
Not used.
1598024001 XR44CX ISA GB r1.0 26.01.2007
Temper.
SET
Compr.
ON
KEY COMBINATIONS:
+

+
+
4.1 USE OF LEDS
Each LED function is described in the following table.
LED MODE
ON Compressor/s enabled
Flashing
Programming phase (flashing with
Anti-short cycle delay enabled
ON Defrost enabled
Flashing
Programming phase (flashing with
Drip time in progress
ON An alarm is occurring
°C/°F ON Measurement unit
°C/°F Flashing Programming phase
5. MAX & MIN TEMPERATURE MEMORIZATION
5.1 HOW TO SEE THE MIN TEMPERATURE
Press and release the n key.
1.
2.
The "Lo" message will be displayed followed by the minimum temperature recorded.
By pressing the n key again or by waiting 5s the normal display will be restored.
3.
5.2 HOW TO SEE THE MAX TEMPERATURE
Press and release the o key.
1.
2.
The "Hi" message will be displayed followed by the maximum temperature recorded.
By pressing the o key again or by waiting 5s the normal display will be restored.
3.
5.3 HOW TO RESET THE MAX AND MIN TEMPERATURE RECORDED
1. Hold press the SET key for more than 3s, while the max. or min temperature is displayed. (rSt
message will be displayed)
2. To confirm the operation the "rSt" message starts blinking and the normal temperature will be
displayed.
6. MAIN FUNCTIONS
Time
6.1 HOW TO SEE THE SETPOINT
display the probe value again.
6.2 HOW TO CHANGE THE SETPOINT
1. Push the SET key for more than 2 seconds to change the Set point value;
2. The value of the set point will be displayed and the
To change the Set value push the o or n arrows within 10s.
3.
4. To memorise the new set point value push the SET key again or wait 10s.
6.3 HOW TO START A MANUAL DEFROST
6.4 HOW TO CHANGE A PARAMETER VALUE
To change the parameter's value operate as follows:
1. Enter the Programming mode by pressing the Set + n keys for 3s (the
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 or wait 15s without pressing a key.
NOTE: the set value is stored even when the procedure is exited by waiting the time-out to expire.
6.5 THE HIDDEN MENU
The hidden menu Includes all the parameters of the instrument.
6.5.1 HOW TO ENTER THE HIDDEN MENU
1. Enter the Programming mode by pressing the Set + n keys for 3s (the "°C" or "°F" LED starts
blinking).
2. Released the keys, then push again the Set+ n keys for more than 7s. The Pr2 label will be
displayed immediately followed from the HY parameter.
NOW YOU ARE IN THE HIDDEN MENU.
3. Select the required parameter.
4. Press the "SET" key to display its value
5. Use o or n to change its value.
6. Press "SET" to store the new value and move to the following parameter.
To exit: Press SET + o or wait 15s without pressing a key.
NOTE1: if none parameter is present in Pr1, after 3s the "noP" message is displayed. Keep the keys
pushed till the Pr2 message is displayed.
NOTE2: the set value is stored even when the procedure is exited by waiting the time-out to expire.
XR44CX
To lock & unlock the keyboard.
To enter in programming mode.
To return to the room temperature display.
FUNCTION
)
)
1. Push and immediately release the SET key: the display will show the Set
point value;
2. Push and immediately release the SET key or wait for 5 seconds to
LED starts blinking;
Push the DEF key for more than 2 seconds and a manual defrost will start.
or LED start
1/3