Dixell XR75CH User Manual

Digital controller for medium-low temperature

The regulation is performed according to the temperature measured by the thermostat probe with a positive differential (HY) over the set point: if the temperature increases and reaches set point plus differential, the compressor will start. It will turn off as soon as the temperature reaches the set point value again.

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.

refrigeration applications

XR75CH

-Manual for the SW rel. 2.6-

1. GENERAL WARNING__________________________________________________________1

2. GENERAL DESCRIPTION ______________________________________________________1

3. CONTROLLING LOADS ________________________________________________________1

4. FRONT PANEL COMMANDS ___________________________________________________1

5. MAX & MIN TEMPERATURE MEMORIZATION _____________________________________2

6. MAIN FUNCTIONS ____________________________________________________________2

7. PARAMETERS _______________________________________________________________2

8. DIGITAL INPUTS _____________________________________________________________4

9. RS485 SERIAL LINE – FOR MONITORING SYSTEMS _______________________________4

10. X-REP OUTPUT – OPTIONAL ___________________________________________________4

11. INSTALLATION AND MOUNTING ________________________________________________4

12. ELECTRICAL CONNECTIONS __________________________________________________4

13. HOW TO: USE THE HOT KEY ___________________________________________________4

14. ALARM SIGNALS _____________________________________________________________4

15. TECHNICAL DATA ____________________________________________________________5

16. CONNECTIONS ______________________________________________________________5

17. DEFAULT SETTING VALUES ___________________________________________________5

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.  Dixell Srl reserves the right to change the composition of its products, even without notice, ensuring

the same and unchanged functionality.

1.2

 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

 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

 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

 In case of applications in industrial environments, the use of mains filters (our mod. FT1) in parallel

2. GENERAL DESCRIPTION

Model XR75CH, format 32x74mm, is microprocessor based controller, suitable for applications on medium or low temperature ventilated refrigerating units. It has four relay outputs to control compressor, fan, defrost, which can be either electrical or reverse cycle (hot gas) and light (configurable). It could be provided with a Real Time Clock which allows programming of up to six daily defrost cycles, divided into holidays and workdays. A “Day and Night” function with two different set points is fitted for energy saving. It is also provided with up to four NTC (EU or US type) probe inputs. The first probe is used for temperature control. The second probe is used to control the defrost termination temperature at the evaporator. One of the two digital inputs can operate as third temperature probe. The fourth probe is used to control the condenser temperature (for condenser alarm management) or to display a temperature. The RS485 serial output allows connecting the unit to a network line (ModBUS-RTU compatible) such as any dIXEL monitoring units of X-WEB family. The HOT-KEY receptacle allows programming the controller by using the HOTKEY programming device. The instrument is fully configurable through special parameters that can be easily programmed through the frontal keyboard.

3. CONTROLLING LOADS

3.1 COMPRESSOR

SAFETY PRECAUTIONS

temperature changes with high atmospheric humidity to prevent formation of condensation

address) with a detailed description of the fault.

other, without crossing or intertwining.

with inductive loads could be useful.

- EdF=rtC, the defrost is real time controlled, depending on the hours set in the parameters

Ld1...Ld6 (for workdays) and in Sd1…Sd6 (for holidays).

Other parameters are used to control defrosting cycles: the maximum length (MdF) and defrosting modes: timed or controlled by the evaporator’s probe (P2P). 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.

3.3 CONTROL OF EVAPORATOR FANS

The fan control mode is selected by means of the FnC parameter: FnC=C_n, fans will switch ON and OFF with the compressor and not run during defrost. FnC=o_n, fans will run even if the compressor is off, and not run during defrost.

After defrost, there is a timed fan delay allowing for drip time, set by means of the “Fnd” parameter. FnC=C_Y, fans will switch ON and OFF with the compressor and run during defrost. FnC=o_Y, fans will run continuously also during defrost.

An additional parameter FSt provides the setting of temperature, detected by the evaporator probe, above which the fans are always OFF. This is used to make sure circulation of air only if his temperature is lower than set in FSt.

3.3.1 Forced activation of fans

This function managed by the FCt parameter is designed to avoid short cycles of fans, that could happen when the controller is switched on or after a defrost, when the room air warms the evaporator. How it works: if the temperature difference between evaporator probe and room probe is higher than the FCt parameter value, fans will be switched on. With FCt=0 the function is disabled.

3.3.2 Cyclical activation of the fans with compressor off.

When FnC=C-n or C-Y (fans working in parallel with the compressor), by means of the Fon and FoF parameters the fans can carry out on and off cycles even if the compressor is switched off. When the compressor is stopped the fans go on working for the Fon time. With Fon=0 the fans remain always off, also when the compressor is off.

3.4 LIGHT RELAY CONFIGURATION (PAR. OA2; TERM. 1-2)

The functioning of the auxiliary relay (terminals. 1-4) can be set by the oA2 parameter, according to the kind of application. In the following paragraph the possible setting:

3.4.1 Light relay

With oA2=LiG the relay 1-2 operates as a light.

3.4.2 Auxiliary relay

a. Relay activation by digital input 2 (oA2=AUS, i2F=AUS) With oA2=AUS and i2F=AUS the relay 1-2 is switched on and off by digital.

b. Auxiliary thermostat

Anti condensing heater with the possibility of switching it on and off also by using the frontal keyboard.

Parameters involved:

- ACH Kind of regulation for the auxiliary relay: Ht = heating; CL = cooling.

- SAA Set point for auxiliary relay.

- SHy Differential for auxiliary relay.

- ArP Probe for auxiliary relay.

- Sdd Auxiliary output off during defrost.

The differential threshold value is set by the SHY parameter.

NOTE: Set oA2=AUS and ArP=nP (no probe for auxiliary output). In this case the relay 1-2 can be activated only by digital input with i1F=AUS or i2F=AUS.

3.4.3 On/off relay (oA2 = onF)

When oA2=onF, the relay is activated when the controller is turned on and de-activated when the controller is turned off.

3.4.4 Neutral zone regulation

With oA2 = db the relay 1-2 can control a heater element to perform a neutral zone action.

 oA2 cut in = [SET-HY]  oA2 cut out = SET

3.4.5 Alarm relay

With oA2 = ALr the relay 1-2 operates as alarm relay. It is activated every time an alarm happens. Its status depends on the tbA parameter: if tbA=Y, the relay is silenced by pressing any key. If tbA=n, the alarm relay remains on until the alarm condition recovers.

3.4.6 Night blind management during energy saving cycles

With oA2=HES, the relay 1-2 operates to manage the night blind: the relay is energised when the energy saving cycle is activated by digital input, frontal button or RTC (optional).

4. FRONT PANEL COMMANDS

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

Two defrost modes are available through the “tdF” parameter: defrost through electrical heater (tdF = EL) and hot gas defrost (tdF = in).

The defrost interval depends on the presence of the RTC (optional). The internal RTC is controlled by means of the EdF parameter:

- EdF=in, the defrost is made every idF time – standard way for controller without RTC.

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(DOWN) To see the min stored temperature; in programming mode it browses the parameter codes or decreases the displayed value.

To switch the instrument on and off (when onF=oFF).

To switch on and off the light (when oA2=LiG).

+ 

To lock & unlock the keyboard.

To enter in programming mode.

To return to the room temperature display.

LED

MODE

FUNCTION

Compressor enabled

Flashing

Anti-short cycle delay enabled

Defrost enabled

Flashing

Drip time in progress

Fans enabled

Flashing

Fans delay after defrost in progress.

An alarm is occurring

Continuous cycle is running

ECO

Energy saving enabled

Light on

Auxiliary relay on

Measurement unit

Flashing

Programming phase

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.

Push the DEF button for more than 2 seconds and a manual defrost will start.

When “onF=oFF”, pushing the ON/OFF key, the instrument is switched off. The “OFF” message is displayed. In this configuration, the regulation is disabled. To switch the instrument on, push again the ON/OFF key.

rtC

Real time clock menu (only for controller with RTC): to set the time, date and defrost start time.

Differential: (0.1 to 25.5°C; 1 to 45°F) intervention differential for set point.

Compressor Cut IN is Set Point + differential (HY). Compressor Cut OUT is when the temperature reaches the set point.

Minimum set point: (-50°C to SET; -58°F to SET) sets the minimum value for the set

point.

Maximum set point: (SET to 110°C; SET to 230°F) set the maximum value for set

point.

Thermostat probe calibration: (-12.0 to 12.0°C; -21 to 21°F) allows to adjust

possible offset of the thermostat probe.

P2P

Evaporator probe presence: (n; Y) n = not present, the defrost stops by time; Y = present, the defrost stops by temperature.

Evaporator probe calibration: (-12.0 to 12.0°C; -21 to 21°F) allows to adjust possible

offset of the evaporator probe.

P3P

Third probe presence (P3): (n; Y) n = not present, the terminals 18-20 operate as digital input; Y = present, the terminals 18-20 operate as third probe.

Third probe calibration (P3): (-12.0 to 12.0°C; -21 to 21°F) allows to adjust possible

offset of the third probe.

P4P

Fourth probe presence: (n; Y) n = Not present; Y = present.

Fourth probe calibration: (-12.0 to 12.0°C; -21 to 21°F) allows to adjust possible

offset of the fourth probe.

odS

Outputs activation delay at start up: (0 to 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.

KEY COMBINATIONS:

4.1 USE OF LEDS

Each LED function is described in the following table.

5. MAX & MIN TEMPERATURE MEMORIZATION

5.1 HOW TO: SEE THE MIN TEMPERATURE

1. Press and release the DOWN button.

2. The “Lo” message will be displayed followed by the minimum temperature recorded.

3. By pressing the DOWN button again or by waiting 5s the normal display will be restored.

5.2 HOW TO: SEE THE MAX TEMPERATURE

1. Press and release the UP button.

2. The “Hi” message will be displayed followed by the maximum temperature recorded.

3. By pressing the UP button again or by waiting 5s the normal display will be restored.

5.3 HOW TO: RESET THE MAX AND MIN TEMPERATURE RECORDED

1. Keep SET button pressed for more than 3s while the max or min temperature is displayed.

(“rSt” message will be displayed)

2. After confirming the operation, the “rSt” message will start blinking and then the normal

temperature will be displayed.

6. MAIN FUNCTIONS

6.1 HOW TO: SET THE CURRENT TIME AND DAY (ONLY WITH RTC)

When the instrument is switched on, it’s necessary to program the time and day.

1. Enter the Pr1 programming menu, by pushing SET + DOWN buttons for 3s.

2. The rtC parameter is displayed. Push SET button to enter the real time clock menu.

3. The HUr (hours) parameter is displayed.

4. Push the SET and set current hour by UP and DOWN buttons, then push SET to

confirm the new inserted value.

5. Repeat these operations for Min (minutes) and dAy (day) parameters.

To exit: Push SET+UP buttons or wait for 15 sec without pushing any keys.

6.2 HOW TO: SEE THE SET POINT

1. Enter the Programming mode by pressing the SET + DOWN buttons for 3s (the °C or °F

start blinking).

2. Select the required parameter. Press the SET button to display its actual value.

3. Use UP or DOWN buttons to change its value.

4. Press SET button to store the new value and move to the following parameter.

To exit: Press SET + UP buttons or wait for 15s without pressing any key.

NOTE: the set value is stored even when the procedure is exited by waiting for the time-out to expire.

LED will

6.6 THE HIDDEN MENU

The hidden menu includes all the parameters of the instrument.

6.6.1 HOW TO: ENTER THE HIDDEN MENU

1. Enter the Programming mode by pressing the SET + DOWN buttons for 3s (the °C or °F

start blinking).

2. Released the buttons and then push again the SET + DOWN buttons for more than 7s. The Pr2

label will be displayed immediately followed from the HY parameter. Now it is possible to browse the hidden menu.

3. Select the required parameter.

4. Press the SET button to display its value.

5. Use UP or DOWN to change its value.

6. Press SET to store the new value and move to the following parameter.

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

NOTE1: if no parameter is present in Pr1 menu, after 3s the “noP” message will be displayed. Keep

the buttons pushed till the Pr2 message will be displayed.

NOTE2: the set value is stored even when the procedure is exited by waiting for the time-out to expire

6.6.2 HOW TO: MOVE A PARAMETER FROM THE HIDDEN MENU TO THE FIRST LEVEL AND VICEVERSA.

Each parameter present in the hidden menu (Pr2) can be moved into the user level (Pr1) by pressing SET + DOWN buttons. If a parameter is part of the user level, when showed in the hidden menu the decimal point will be lit.

LED will

6.7 HOW TO: LOCK THE KEYBOARD

1. Keep both UP and DOWN buttons pressed for more than 3s.

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 button is pressed more than 3s the “PoF” message will be displayed.

6.8 HOW TO: UNLOCK THE KEYBOARD

Keep both UP and DOWN pressed for more than 3s till the “Pon” message will be displayed.

6.9 THE CONTINUOUS CYCLE

When defrost is not in progress, it can be activated by keeping the UP button pressed for about 3 seconds. The compressor operates to maintain the CCS set point for the time set through the CCt parameter. The cycle can be terminated before the end of the set time using the same activation button (UP for 3 seconds).

6.10 THE ON/OFF FUNCTION

WARNING: Loads connected to the normally closed contacts of the relays are always supplied and under voltage, even if the instrument is in stand by mode.

7. PARAMETERS

RTC

REGULATION

6.3 HOW TO: CHANGE THE SET POINT

1. Push the SET button for more than 2 seconds to change the Set point value.

2. The value of the set point will be displayed and the °C or °F

3. To change the actual value, push the UP or DOWN buttons within 10s.

4. To memorise the new set point value, push the SET button again or wait 10s.

LED will start blinking.

6.4 HOW TO: START A MANUAL DEFROST

6.5 HOW TO: CHANGE A PARAMETER VALUE

To change a parameter value, operate as follows:

1592038060 XR75CH GB r1.0 25.02.2015 XR75CH 2/6

+ 4 hidden pages

Dixell XR75CH User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual