dixell XR20Ce, XR20D, XR20C Installing And Operating Instructions

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 it s 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 1/2

Dixell

Installing and Operating Instructions

XR20CE2probecooling XR20C 2/2

• COF Compressor OFF time with faulty probe:
(0÷255 min) time during which the compressor is OFF
in case of faulty thermostat probe. With COF=0

compressor is always active.

DISPLAY

• CF Temperature measurement unit: °C =
Celsius; °F= Fahrenheit. WARNING: When the
measurement unit is changed the SET point and the
values of the parameters Hy, LS, US and Ot have to be
checked and modified if necessary).

rES Resolution (for °C): (in = 1°C; dE = 0.1 °C) allows the

decimal point displaying.

DEFROST
dtE Defrost termination temperature: (-50÷50 °C/

-58÷122°F) (Enabled only when P2P=y) sets the
temperature measured by the evaporator probe, which
causes the end of defrost.

IdF Interval between defrost cycles: (1÷120h) Determines

the time interval between the beginning of two defrost
cycles.

MdF Length for defrost: (0÷255min) It sets the defrost

duration.

• dFd Temperature displayed during defrost: (rt = real
temperature; it = temperature at defrost start; SEt = set
point; dEF = “dEF” label)

• dAd MAX display delay after defrost: (0÷255min).
Sets the maximum time between the end of defrost and
the restarting of the real room temperature display.

DIGITAL INPUT
i1P Digital input polarity: oP: the digital input is activated

by opening the contact; CL: the digital input is activated
by closing the contact.

did: (0÷255 min) door open signalling delay

• odc Compressor status when open door:

no=Digital Input not used CPr= Compressor OFF.

OTHER
rEL Software release for internal use.

Ptb Parameter table index: readable only. For internal use.

7. DIGITAL INPUT

7.1 DIGITAL INPUTS POLARITY

The digital input polarity depends on the “i1P” parameter.
i1P=CL: the input is activated by closing the contact.
i1P=OP: the input is activated by opening the contact

8. INSTALLATION AND MOUNTING

Instrument XR20C shall be mounted on panel, in a 29x71
mm hole, and fixed using the special brackets supplied.

To obtain an IP65 protection grade use the front panel rubber
gasket (mod. RG-C) as shown in figure.

The temperature range allowed for correct operation is 0÷60
°C. Avoid places subject to strong vibrations, corrosive

gases, excessive dirt or moisture. The same
recommendations apply to probes. Let air circulate by the

cooling holes.

9. ELECTRICAL CONNECTIONS

The instruments are provided with screw terminal block to
connect cables with a cross section up to 2,5 mm

2

. Heat­resistant cables have to be used. Before connecting cables
make sure the power supply complies with the instrument’s

requirements.

Separate the probe cables from the power

supply cables, from the outputs and the power
connections. Do not exceed the maximum current allowed

on each relay, in case of heavier loads use a suitable
external relay.

9.1 PROBE CONNECTION

The probes shall be mounted with the bulb upwards to
prevent damages due to casual liquid infiltration. It is

recommended to place the probe away from air streams to
correctly measure the average room temperature.

10. HOW TO USE THE HOT KEY

10.1 HOW TO PROGRAM A HOT KEY FROM THE
INSTRUMENT (UPLOAD)

1. Program one controller with the front keypad.

2. When the controller is

ON, insert the “Hot key” and
push o key; the "uPL" message appears followed a
The word “End”

3. Push “SET” key and the End will stop being displayed.

4.

Turn OFF the instrument remove the “Hot Key”, then
turn it ON again.

NOTE: the “Err” message is displayed for failed
programming. In this case push again o key if you want to
restart the upload again or remove the “Hot key” to abort the
operation.

10.2 HOW TO PROGRAM AN INSTRUMENT
USING A HOT KEY (DOWNLOAD)

1. Turn OFF the instrument.

2. Insert a programmed “Hot Key” into the 5 PIN

receptacle and then turn the Controller ON.

3. Automatically the parameter list of the “Hot Key” is

downloaded into the Controller memory, the “doL”
message is blinking followed a by “End”.

4. After 10 seconds the instrument will restart working

with the new parameters.

5. Remove the “Hot Key”.

NOTE the message “Err” is displayed for failed programming.
In this case turn the unit off and then on if you want to restart
the download again or remove the “Hot key” to abort the
operation.

11. ALARM SIGNALS

Message Cause Output

“EE” Data or memory failure
“P1” Room probe failure Output according to par.

“Con” and “COF”

“P2” 2nd probe failure Output unchanged

“dA” Door open Regulation restarts

11.1 ALARM “EE”

The instrument is provided with an internal check verifying
memory integrity. Alarm “EE” flashes when a failure in the
internal memory is detected. In such case call the service.

11.2 ALARM RECOVERY

Probe alarm “P1 & P2” start some seconds after the fault in
the related probe; it automatically stops some seconds after
the probe restarts normal operation. Check connections
before replacing the probe.
Alarm dA will recover as soon as the digital input is disabled.

12. TECHNICAL DATA

Housing: self extinguishing ABS.
Case: XR20C frontal 32x74 mm; depth 60mm;
Mounting

XR20C panel mounting in a 71x29mm panel cut-out

Protection: IP20.
Frontal protection:
XR20C IP65 with frontal gasket RG-C (optional).
Connections: Screw terminal block ≤ 2,5 mm

2

heat­ resistant wiring.
Power supply: according to the model: 12Vac/dc, ±10%;
24Vac/dc, ±10%; 230Vac ±10%, 50/60Hz, 110Vac ±10%,
50/60Hz

Power absorption: 3VA max
Display: 3 digits, red LED, 14,2 mm high.
Inputs: 2 NTC probes. 1 Digital input
Relay outputs
Compressor:
SPST relay 16FLA/96LRA

Data storing: on the non-volatile memory (EEPROM).
Kind of action: 1B.
Pollution grade: normal
Software class: A.
Operating temperature: 0÷60 °C.
Storage temperature: -25÷60 °C.
Relative humidity: 20÷85% (no condensing)
Measuring and regulation range:

NTC probe: -40÷110°C (-58÷230°F)
Resolution: 0,1 °C or 1°C or 1 °F (selectable).
Accuracy (ambient temp. 25°C): ±0,7 °C ±1 digit

13. CONNECTIONS

13.1 XR20C: 16FLA COMPRESSOR

456 7

9101112

Comp

Room

8

Hot Key

Line

Supply
120V~

120Vac supply: connect to the terminals 7 and 8.
OPTIONAL:

12Vac/dc supply: connect to the terminals 7 and 8.
24Vac/dc supply: connect to the terminals 7 and 8.
230Vac supply: connect to the terminals 7 and 8.

14. DEFAULT SETTING VALUES

Label Name Range °C/°F

Set

Set point LS÷US

3/37

Hy

Differential

0,1÷25.5°C/

1÷ 45°F

2/4

LS

Minimum set point

-50°C÷SET/

-58°F÷SET

-40/

- 40

US

Maximum set point

SET÷150°C/
SET ÷ 230°F

110/

230

Ot

Thermostat probe calibration

-12÷ 12°C /

-21 ÷ 21°F

0/0

P2P

2nd probe presence Y/N

Y

OE

2

nd

probe calibration

-12÷12°C /­120÷120°F

OdS

Outputs delay at start up 0÷255 min

0

AC

Anti-short cycle delay

0 ÷ 50 min

1

COn

Compressor ON time with faulty
probe

0 ÷ 255 min

15

COF

Compressor OFF time with faulty
probe

0 ÷ 255 min

30

CF

Temperature measurement unit

°C ÷ °F

°C/°F

rES

Resolution

in ÷ dE

dE/-

dtE

Defrost end temp

-50 ÷ 50 °C

46

IdF

Interval between defrost cycles

1 ÷ 120 hour

8

MdF

(Maximum) length for defrost

0 ÷ 255 min

20

dFd

Displaying during defrost rt, it, SEt,

DEF

it

dAd

MAX display delay after defrost 0 ÷ 255 min 30

i1P

Digital input polarity oP=opening;

CL=closing

cL

did

Digital input alarm delay 0÷255min 5

odc

Compressor status with open door:

No=No Digital

input used.

CPr; =

Compressor

off

no

rEL

Software release -- -

Ptb

Map code -- -

Hidden parameters

Dixell s.r.l. Z.I. Via dell’Industria, 27
32010 Pieve d’Alpago (BL) ITALY
tel. +39 - 0437 - 98 33 - fax +39 - 0437 - 98 93 13
E-mail: [e-mail] - http://www.dixell.com