Dixell
Installing and Operating Instructions
Thermostat with off cycle defrost
XR20Ce COOLING
CONTENTS
1. GENERAL
WARNING_______________________1
2. GENERAL
DESCRIPTION ___________________1
3. CONTROLLING
LOADS _____________________1
4. FRONT PANEL COMMANDS_________________1
5. MAIN
FUNCTIONS _________________________1
6. LIST OF PARAMETERS _____________________1
7. DIGITAL
INPUT____________________________2
8. INSTALLATION AND MOUNTING _____________2
9. ELECTRICAL
CONNECTIONS________________2
10. HOW TO USE THE HOT KEY ________________2
11. ALARM SIGNALS __________________________2
12. TECHNICAL DATA _________________________2
13. CONNECTIONS ___________________________2
14.
DEFAULT SETTING VALUES 2
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.
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.
•
The instrument must not be opened.
•
Fit the probe where it is not accessible by the end user.
•
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.
2. GENERAL
DESCRIPTION
Model XR20C, format 32 x 74 mm, is thermostat with off
cycle defrost designed for refrigeration applications at normal
temperature. It provides a relay output to drive the
compressor and a NTC probe input. A internal timer
manages the off cycle defrost. The instrument is fully
configurable through special parameters that can be easily
programmed through the 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 DEFROST
Defrost is performed through a simple stop of the
compressor. Parameter “IdF” controls the interval between
defrost cycles, while its length is controlled by parameters
“MdF & dtE”. MdF is used for a timed defrost end when
P2P= n. When P2P= y, then dtE will end defrost by
temperature.
4. FRONT PANEL COMMANDS
SET: To display target set point; in programming mode it
selects a parameter or confirm an operation.
(DEF)
To start a manual defrost
o
(UP): To see the max. stored temperature; in
programming mode it browses the parameter codes or
increases the displayed value.
n
(DOWN)
To see the min stored temperature; in
programming mode it browses the parameter codes or
decreases the displayed value.
KEY COMBINATIONS:
o
+
n
To lock & unlock the keyboard.
SET +
n
To enter the programming mode.
SET +
o
To return to the room temperature display.
4.1 MEANING OF LEDS
Each LED function is described in the following table.
LED MODE
FUNCTION
ON Compressor
enabled
Flashing -Programming Phase (flashing with
)
- Anti-short cycle delay enabled
ON Defrost
enabled
Flashing - Programming Phase (flashing with
)
- Drip time in progress
5. MAIN
FUNCTIONS
5.1 HOW TO SEE THE SETPOINT
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 display the probe value again.
5.2 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
LED starts blinking;
3. To change the Set value push the
o
or
n
arrows.
4. To memorise the new set point value push the SET key
again or wait 15s.
5.3 HOW TO START A MANUAL DEFROST
Push the DEF key for more than 2
seconds 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 and
n
key for 3s (
and
start blinking).
2. Select the required parameter.
3. Press the “SET” key to display its value. (Now only the
LED is blinking).
4. Use
o
or
n
to change its value.
5. 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.
5.5 THE HIDDEN MENU
The hidden menu Includes all the parameters of the
instrument.
5.5.1 HOW TO ENTER THE HIDDEN MENU
Enter the Programming mode by
pressing the Set +
n
key for 3s
(
and
start blinking).
1. When a parameter is displayed
release and then press the Set+
n
again for more than 7s. The Pr2 label will
be displayed immediately followed from the HY parameter.
NOW YOU ARE IN THE HIDDEN MENU.
2. Select the required parameter.
3. Press the “SET” key to display its value (Now only the
LED is blinking).
4. Use
o
or
n
to change its value.
5. 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.
NOTE: the set value is stored even when the procedure is
exited by waiting the time-out to expire.
5.5.2 HOW TO MOVE A PARAMETER FROM
THE HIDDEN MENU TO THE FIRST LEVEL
AND VICEVERSA.
Each parameter present in the HIDDEN MENU can be
removed or put into “THE FIRST LEVEL” (user level) by
pressing “SET +
n
”.
In the HIDDEN MENU when a parameter is present in Fisrt
Level the decimal point is on.
5.6 HOW TO LOCK THE KEYBOARD
1.
Keep pressed for more than 3 s the
o
and
n
keys.
2.
The “POF” message will be displayed and the keyboard
will be locked. At this point it will be possible only to see
the set point or the MAX o Min temperature stored
3.
If a key is pressed more than 3s the “POF” message will
be displayed.
5.7 TO UNLOCK THE KEYBOARD
Keep pressed together for more than 3s the
o
and
n
keys
till the Pon message will be displayed.
6. LIST OF PARAMETERS
NOTE: the parameters preceded by dots are only in the
Hidden Menu.
REGULATION
Hy Differential: (0,1 ÷ 25,5°C / 1÷45 °F) Intervention
differential for set point. Compressor Cut IN is Set Point
Plus Differential (Hy). Compressor Cut OUT is when the
temperature reaches the set point.
•
LS Minimum set point: (- 50°C÷SET / -58°F÷SET):
Sets the minimum acceptable value for the set point.
•
US Maximum set point: (SET÷ 150°C / SET÷302°F).
Set the maximum acceptable value for set point.
•
Ot Thermostat probe calibration: (-12.0÷12.0°C; --
21÷21°F) allows the adjustment of possible offset of the
thermostat probe.
•
P2P Evaporator probe presence: n= not present:
the defrost stops by time; y= present: the defrost stops
by temperature.
•
OE Evaporator probe calibration: (-12.0÷12.0°C; -
120÷120°F). allows to adjust possible offset of the
evaporator probe.
•
OdS
Outputs activation delay at start
up: (0÷255min) 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÷50 min) minimum interval
between the compressor stop and the following restart.
•
COn Compressor ON time with faulty probe: (0÷255
min) time during which the compressor is active in case
of faulty thermostat probe. With COn=0 compressor is
always OFF.
XR20CE2probecooling
XR20C
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