dixell XR420C Installing And Operating Instructions

dIXEL

Installing and Operating Instructions

1598026100

1598026100 XR420C GB r1.0 22.02.2007.doc XR420C 1/4

XR420C

DUAL TEMPERATURE CONTROLLER

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 or to “Dixell

S.p.A.” (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 XR420C, 32x74 mm format, is a microcontroller based device, able to control 2 temperatures
in an independent way. Both sections are suitable for applications on normal or medium
temperature refrigerating units or cooking applications. It is provided with 3 relay outputs to control
two compressors and one light. Defrost process is performed through simple stop of compressors.
It is also provided with 2 NTC or PTC probe inputs, one for section 1 and the other one for section 2.
There is one digital input (free voltage contact) completely configurable by parameter. The standard
TTL output allows the user to connect, by means of a TTL/RS485 external module, a ModBUS-RTU
compatible monitoring system and to programme the parameter list with the “Hot Key”.

3. REGULATION

Two kinds of actions are available for both sections: cooling action and heating action. The type is
selected through cH1/cH2 section parameter.

3.1 HOW TO SET THE TYPE OF ACTION

By means of CH1/2 parameters the kind of action can be set for each section: cH1/cH2 = CL:
refrigerating action (1/2); cH1/cH2 = Ht: heating action (1/2)

3.2 CH1/CH2 = CL FOR COOLING ACTION

For each section, the regulation is
performed according to the
temperature measured by its own
thermostat probe with a positive
differential from the set point.
If the temperature increases and
reaches set point1 (2) plus
differential1 (2) 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 “COn1(2)” and
“COF1(2)”.

3.3 CH1/CH2 = HT FOR HEATING ACTION

For each section, the regulation is performed
according to the temperature measured by its
own thermostat probe with a negative
differential from the set point. If temperature
decreases and reaches set point 1/2 minus
differential 1/2 the output is activated and then
turned off when the temperature reaches the
set point value again and then turned off when
the temperature reaches the set point value
again.

NOTE: For turn-off defrost you can set
MdF1/MdF2 = 0.

4. DEFROST

4.1 SECTION 1 (2)

Defrost is performed through a simple stop of the compressor for both sections. Different kinds of
defrosts are available for each section.

4.2 RELATION BETWEEN DEFROSTS

The relation between defrosts is set by the dFS parameter: relation between defrosts.
4 relation between the 2 sections of the controller are available, to manage different kinds for
applications:

- in = independent defrosts;

- StS = same defrost start, synchronised defrost end;

- St = same defrost start, independent defrost end;

- SE = sequential defrost;

4.2.1 dFS= in - independent defrosts

The defrosts of the 2 sections of controller are completely independent.

First section: defrost interval is set by idF1 parameter.
Second section: defrost interval is set by idF2 parameter.
The defrost interval is control by means of parameter “EdF1(2)”:

- in the defrost is made every “IdF1(2)” time

- Sd the interval “IdF1(2)” is calculate through Smart Defrost algorithm (only when the

compressor is ON)

Manual defrost activation, by pushing the DOWN key (defrost 1) or UP key (defrost 2).

By pushing the Down key or Up key for 3s, a defrost request is generated for section 1 or 2
respectively. The defrost interval is re-loaded.

4.2.2 dFS = StS – Same defrost start, end defrost synchronised or dFS = St

- Same defrost start, end defrost independent.

The defrost of the 2 sections of controller starts at the same time. idF1 parameter sets the defrost
interval for both the sections. The defrosts are performed at regular interval if EdF1 = in or according
to the Smartdefrost algorithm if EdF1 = Sd.

With dFS = StS regulation restarts only when defrost is finished for both the sections. The section
that finishes the defrost before the other starts dripping time until also the other section has not
finished its defrost.

Manual defrost activation, by pushing the DOWN key (defrost 1) or UP key (defrost 2).

By pushing the Down key or Up key for 3s, a defrost request is generated for both the sections 1
and 2.The defrost interval is re-loaded.
With dFS = St each section restarts regulation as soon as its defrost is finished.

4.2.3 dFS = SE – sequential defrost

The defrost of 2 sections is synchronised. idF1 parameter sets the defrost interval for both the
sections. Defrosts are performed at regular interval if EdF1 = in or according to the Smartdefrost
algorithm if EdF1 = Sd. Section 1 does its defrost first, at the end of the defrost of section 1, section
2 starts its defrost..

Manual defrost activation, by pushing the DOWN key (defrost 1) or UP key (defrost 2).

By pushing the Down key or Up key for 3s, a defrost request is generated for both the sections 1
and 2.The defrost interval is re-loaded.

5. THE DISPLAY

X----C

XR400

The display is divided in 2 parts:

Upper left part: to see the temperature2 (upper display)
Lower left part: to see the temperature1(lower display)

SET To display and modify target set point 1 and set point 2, in programming mode it

selects a parameter or confirm an operation.
light activation/deactivation.

o/

(UP/DEFROST 2) in programming mode it browses the parameter codes or
increases the displayed value. By holding it pressed for 3s the defrost for section 2
is started

.

n/

(DOWN/DEFROST 1) in programming mode it browses the parameter codes or
decreases the displayed value. By holding it pressed for 3s the defrost for section 1
is started.

o + n

To lock and unlock the keyboard.

SET +

n To enter the programming mode.

SET +

o To exit the programming mode.

5.1 MEANING OF THE ICONS

Icon FUNCTION Meaning

ON Celsius degree
ON Fahrenheit degree
ON Compressor 1 on

FLASHING Anti-short cycle delay enabled for compressor 1

ON Compressor 2 on

FLASHING Anti-short cycle delay enabled for compressor 2

ON Defrost 1 in progress

ON Defrost 2 in progress

ON ALARM signal

Temperature2

Temperatature1

dIXEL

Installing and Operating Instructions

1598026100

1598026100 XR420C GB r1.0 22.02.2007.doc XR420C 2/4

5.2 HOW TO SEE AND MODIFY THE SET-POINT

1. Push and release the SET key:

2. the bottom display shows the St1 label

3. the upper display shows the Set point value flashing

4. To change the Set value push the o or n;

5. To memorise the new set point value push the SET key again,

6. To change the SET2 repeat this procedure.

5.3 HOW TO START MANUAL DEFROST FOR THE SECTION 1 OR SECTION 2

To start a defrost for the section 1: push the DOWN key( ) for 3s.
To start a defrost for the section 2: push the UP key(

) for 3s.

5.4 HOW TO ENTER THE “PR1” PARAMETER LIST

To change the parameter’s value operate as follows:

1. Enter the Programming mode by pressing the Set1 and DOWN key for 3s

2. The controller will show the first parameter present in the Pr1 menu:

- Bottom menu: label

- Upper menu: value

To exit: Press SET + UP or wait 15s without pressing a key.

5.5 HOW TO ENTER IN PARAMETERS LIST “PR2”

To access parameters in “Pr2”:

1. Enter the “Pr1” level.

2. Select “Pr2” – “PAS” parameter and press the “SET” key.

3. The flashing value “0 - - ” is displayed. use o or n to input the security code and confirm the
figure by pressing “SET” key.

The security code is “321”.

4. If the security code is correct the access to “Pr2” is enabled by pressing “SET1” on the last
digit.

NOTE: Each parameter present in “Pr2” MENU can be removed or put into “Pr1”, user level, by
pressing “SET1 + n”. In “Pr2” when a parameter is present in “Pr1” the decimal point LE of the
bottom display is on.

5.6 HOW TO CHANGE A PARAMETER

To change a parameter value operates as follows:

1. Enter the Programming mode

2. Select the required parameter.

3. Press the “SET” key and the value starts blinking.

4. Use “UP” or “DOWN” 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.

5.7 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 points.

3. If a key is pressed more than 3s the “POF” message will be
displayed.

5.8 TO UNLOCK THE KEYBOARD

Keep pressed together for more than 3s the o and n keys, till the “Pon” message will be
displayed.

5.9 ON/OFF FUNCTION – HOW TO SWITCH ON AND OFF THE CONTROLLER

If the function is enabled (par. onF=yES), by pressing the SET key for more than 5s the controller is
switched OFF. The stand-by function switches OFF all the relays and stops the regulation. During
the stand by if a monitored unit is connected, it does not record the instrument data and alarms

To switch the instrument on again press the SET1 key for 5s.

NOTE1: When the instrument is under Stand-by, all the relays are under power supply. Don’t
connect any loads to the normal closed contact of the relays.
NOTE2: With the instrument in stand-by, it’s possible to see and modify the set points and
enter the programming mode.

6. PARAMETER LIST

DIFFERENTIALS

Hy1 Differential1: (0,1÷25,5°C; 1÷45°F): Intervention differential for set point1, always positive.

Compressor1 Cut IN is Set Point Plus Differential1 (Hy1). Compressor1 Cut OUT is when
the temperature reaches the set point1.

Hy2 Differential2: (0,1÷25,5°C; 1÷45°F): Intervention differential for set point2, always positive.

Compressor2 Cut IN is Set Point2 Plus Differential2 (Hy2). Compressor2 Cut OUT is when
the temperature reaches the set point2.

REGULATION – SECTION 1

LS1 Minimum set point1 limit: (-50,0°C÷SET1; -58°F÷SET1) Sets the minimum acceptable

value for the set point1.

US1 Maximum set point1 limit: (SET1

÷110°C; SET1÷230°F) Set the maximum acceptable

value for set point1.

OdS1 Outputs activation delay of section 1 at start up: (0÷255 min) This function is enabled at

the initial start up of the instrument and inhibits any output activation of the section 1 for the
period of time set in the parameter. (Light can work)

AC1 Anti-short cycle delay for compressor1: (0÷30 min) interval between the compressor1

stop and the following restart.

Con1 Compressor1 ON time with faulty probe1: (0÷255 min) time during which the

compressor1 is active in case of faulty thermostat probe. With COn=0 compressor1 is
always OFF.

COF1 Compressor1 OFF time with faulty probe1: (0÷255 min) time during which the

compressor is off in case of faulty thermostat probe. With COF=0 compressor is always
active.

CH1 Kind of action for section 1: CL = cooling; Ht = heating

REGULATION – SECTION 2

LS2 Minimum set point2 limit: (-50,0°C÷SET2; -58°F÷SET2) Sets the minimum acceptable

value for the set point2.

US2 Maximum set point2 limit: (SET2

÷110°C; SET2÷230°F) Set the maximum acceptable

value for set point2.

OdS2 Outputs activation delay of section 2 at start up: (0÷255 min) This function is enabled at

the initial start up of the instrument and inhibits any output activation of the section 1 for the
period of time set in the parameter.

Ac2 Anti-short cycle delay for compressor2: (0÷30 min) interval between the compressor2

stop and the following restart.

con2 Compressor2 ON time with faulty probe2: (0÷255 min) time during which the

compressor2 is active in case of faulty thermostat probe. With COn=0 compressor2 is
always OFF.

coF2 Compressor2 OFF time with faulty probe2: (0÷255 min) time during which the

compressor is off in case of faulty thermostat probe. With COF=0 compressor2 is always
active.

cH2 Kind of action for section 2: CL = cooling; Ht = heating

DISPLAY

CF Temperature measurement unit: °C = Celsius; °F = Fahrenheit. When the measurement

unit is changed the SET point and the values of some parameters have to be modified.

rES Resolution (for °C): (in = 1°C; de = 0,1°C) allows decimal point display. dE = 0,1°C; in = 1

°C

Lod1 Bottom display visualization: select which probe is displayed by the instrument in the

bottom display: P1 = Thermostat1 probe; P2 = Evaporator probe; P2 = Thermostat2 probe

Lod2 Upper display visualization: select which probe is displayed by the instrument in the

upper display: P1 = Thermostat1 probe; P2 = Evaporator probe; P2 = Thermostat2 probe

DEFROST

dFS relation between defrosts.4 relation between the 2 sections of the controller are available,

to manage different kinds for applications: in = independent defrosts;

StS = same defrost start, synchronised defrost end; St = same defrost start, independent

defrost end; SE = sequential defrost;

EdF1 Defrost mode, section 1: in = interval mode. The defrost starts when the time “If” is

expired.

IdF1 Interval between defrosts, section 1: (1÷120h) Determines the time interval between the

beginning of two defrost cycles.

MdF1 Maximum duration of defrost, section 1: (0÷255 min) When P2P = no, no evaporator

probe, it sets the defrost duration, when P2P = yES, defrost end based on temperature, it
sets the maximum length for defrost.

EdF2 Defrost mode, section 2: in = interval mode. The defrost starts when the time “IdF" is

expired.

IdF2 Interval between defrosts, section 2: (1÷120h) Determines the time interval between the

beginning of two defrost cycles.

MdF2 (Maximum) duration of defrost, section 2: (0÷255 min) it sets the defrost duration.
dFd Display during defrost: rt = real temperature; it = temperature reading at the defrost

start; Set = set point; dEF = “dEF” label; dEG = “dEG” label;

dAd Defrost display time out: (0

÷255 min) Sets the maximum time between the end of defrost

and the restarting of the real room temperature display.

ALARMS
ALc1 Temperature alarms configuration, section 1: it determines if alarms are relative to set

point 1 or referred to absolute values: rE relative to set point; Ab absolute temperature

ALu1 Maximum alarm, section 1:
with ALc1=rE: alarm relative to set point1, (0÷50°C) Maximum alarm is enabled when the

probe values exceeds the “SET1+ALU” value.

with ALc1=Ab: absolute alarm, (Set1÷Full Sc.) Maximum alarm is enabled when the probe

values exceeds the “ALU” value.
ALL1 Minimum alarm, section 1:
with ALc1=rE: relative to set point1, (0÷50°C) this value is subtracted from the set point1.

The alarm signal is enabled when the probe values goes below the “SET1-ALL” value.
with ALc1=Ab absolute value, minimum alarm is enabled when the probe values goes

below the “ALL1” value.
ALd1 Temperature alarm delay, section 1: (0÷255 min) time interval between the detection of

an alarm condition and the corresponding alarm signalling.
dAo1 Delay of temperature alarm at start-up, section 1: (0min÷23h 50min) time interval

between the detection of the temperature alarm condition in section after the instrument

power on and the alarm signalling.
ALc2 Temperature alarms configuration, section 2: it determines if alarms are relative to set

point 2 or referred to absolute values: rE relative to set point; Ab absolute temperature

ALu2 Maximum alarm, section 2:
with ALc2=rE: alarm relative to set point1, (0÷50°C) Maximum alarm is enabled when the

probe values exceeds the “SET2+ALU” value.
with ALc2=Ab: absolute alarm, (Set2÷Full Sc.) Maximum alarm is enabled when the probe

values exceeds the “ALU” value.
ALL2 Minimum alarm, section 2:
with ALc2=rE: relative to set point1, (0÷50°C) this value is subtracted from the set point2.

The alarm signal is enabled when the probe values goes below the “SET2-ALL” value.
with ALc2=Ab absolute value, minimum alarm is enabled when the probe values goes

below the “ALL2” value.
ALd2 Temperature alarm delay, section 2: (0÷255 min) time interval between the detection of

an alarm condition and the corresponding alarm signalling.
dAo2 Delay of temperature alarm at start-up, section 2: (0min÷23h 50min) time interval

between the detection of the temperature alarm condition in section after the instrument

power on and the alarm signalling.
AFH Temperature alarm / defrost differential: (0,1÷25,5°C; 1÷45°F) Intervention differential

for temperature alarm set point and defrost set point.