Dixell XR Series Digital Controllers
Models: XR01CX, XR02CX, XR03CX, XR04CX, XR06CX
Manufacturer: Dixell (Emerson)
1. General Warnings
This manual is an integral part of the product and should be kept readily accessible. The instrument is designed for specific applications and should not be used for other purposes or as a safety device. Always verify application limits before use. Dixell Srl reserves the right to modify product composition without prior notice, ensuring continued functionality.
- Ensure the supply voltage is correct before connecting the instrument.
- Avoid exposure to water or moisture. Operate within specified limits and prevent condensation due to sudden temperature changes.
- Disconnect all electrical connections before performing any maintenance.
- Install probes out of reach of the end-user. Do not open the instrument.
- In case of malfunction, return the instrument to the distributor or Dixell S.r.l. with a detailed fault description.
- Observe the maximum current ratings for each relay (refer to Technical Data).
- Separate probe, load, and power supply wiring to prevent interference.
- Consider using mains filters (e.g., Dixell mod. FT1) for inductive loads in industrial environments.
1.3 Disposal of the Product
Dispose of the appliance separately according to local waste disposal regulations.
2. Front Panel
The front panel features a 2-digit red LED display (14.2 mm high) and control keys for operation and programming.
Front Panel Commands:
- SET Key: Displays target setpoint, enters programming mode, confirms operations.
- ▶ (Up) Key: Browses parameter codes or increases displayed value in programming mode.
- ◀ (Down) Key: Browses parameter codes or decreases displayed value in programming mode.
- DEF Key: Starts manual defrost (requires evaporator probe temperature below dE).
- HOT KEY Receptacle: For programming and data transfer.
Key Combinations:
- SET + ▶ (3s): Enter programming mode.
- SET + ▶ (7s): Enter hidden menu (after entering programming mode).
- ▶ + ◀ (3s): Lock/unlock the keyboard (displays 'OF' or 'On').
- SET + ◀ (3s): Reset parameters to factory default.
- Return to Room Temperature Display: Push SET key briefly.
LED Indicators:
- On (Compressor): Compressor enabled.
- Flashing (Compressor): Compressor activation delay active or compressor stopped due to mic-rdooor.
- On (Defrost): Defrost in progress.
- Flashing (Defrost): Defrost delay active or dripping in progress.
- On (Fans): Fans output enabled.
- Flashing (Fans): Fans delay after defrost.
- On (Alarms): Alarms present.
- Flashing (Alarms): Indicates specific alarm conditions (refer to manual for details).
3. Dimensions and Cut Out
The controllers have a short format of 32x74 mm with a depth of 50 or 60 mm. They are designed for panel mounting with a 71x29 mm cut-out.
Housing: Self-extinguishing ABS.
Mounting: Panel mounting.
Protection: IP20 (standard), IP65 (frontal).
4. Connections
Connections are made via a screw terminal block suitable for wires up to 2.5 mm². Ensure proper separation of power supply, signal, and load cables. Do not exceed the maximum current ratings for relays; use external relays for heavier loads.
Power Supply: Varies by model (12Vac/dc, 24Vac/dc, 110Vac, 230Vac).
Inputs: Up to 2 NTC probes, 1 digital input (free voltage contact).
Relay Outputs: Compressor (8(3)A, 16(5)A, or 20(8)A @ 250Vac), Defrost/Auxiliary (8(3)A @ 250Vac), Fan (8(3)A or 5(2)A @ 250Vac).
5. General Description
The Dixell XR series controllers are microprocessor-based devices designed for temperature control in refrigeration and heating applications. Different models offer specific functionalities:
- XR01CX: Single-stage thermostat for refrigeration/heating, with one relay output for the compressor, 1 NTC probe input, and 1 digital input.
- XR02CX: Digital controller with off-cycle defrost for normal temperature refrigeration, featuring a compressor relay output, 1 NTC probe input, and 1 digital input.
- XR03CX: Microprocessor-based controller for normal temperature refrigeration units, with two relay outputs (compressor and alarm/auxiliary), 1 NTC probe input, and 1 digital input for alarm or auxiliary control.
- XR04CX: Microprocessor-based controller for normal or low-temperature refrigeration units, with two relay outputs (compressor and defrost), and two NTC probe inputs (room and defrost termination).
- XR06CX: Microprocessor-based controller for medium or low-temperature ventilated refrigeration units, with three relay outputs (compressor, fan, and defrost), and two NTC probe inputs (temperature control and evaporator monitoring). It also includes a configurable digital input.
All models are configurable via the keyboard or the HOTKEY device.
6. Regulation
6.1 The Regulation Output (Only for XR01CX)
Regulation is based on the temperature measured by the probe. The 'CH' parameter determines the application type:
- CH=cL: Cooling applications.
- CH=Ht: Heating applications.
In cooling mode, the compressor starts when the temperature reaches setpoint plus differential and stops when it reaches the setpoint.
6.2 Cooling Applications
Regulation is performed according to the temperature measured by the probe. The 'CH' parameter enables setting for cooling (cL) or heating (Ht) applications. In cooling, the compressor starts when the temperature reaches setpoint plus differential and stops when it reaches the setpoint.
6.3 Heating Applications (Only XR01CX)
The 'Hy' value is subtracted from the setpoint. The output starts when the temperature drops to setpoint minus differential and stops when it reaches the setpoint.
7. Defrost
- XR02CX - XR03CX: Defrost is achieved by stopping the compressor. Parameter 'id' controls the defrost interval, and 'Md' controls its duration.
- XR04CX - XR06CX: Two defrost modes are available via the 'td' parameter:
- td=EL: Defrost via electrical heater (compressor OFF).
- td=in: Hot gas defrost (compressor ON).
Additional parameters control the defrost interval ('id'), maximum defrost length ('Md'), and defrost termination based on temperature (using the evaporator probe, P2). After defrost, a dripping time ('dt') can be set. If 'dt=0', dripping time is disabled.
Defrost at power-on ('dP'): If 'dP=y', defrost starts upon power-on. If 'dP=n', defrost does not start.
8. Fans (Only XR06CX)
The 'FC' parameter configures fan operation:
- FC=cn: Fans run with the compressor, OFF during defrost.
- FC=on: Fans run continuously, OFF during defrost.
- FC=cY: Fans run with the compressor, ON during defrost.
- FC=oY: Fans run continuously, ON during defrost.
The 'Fd' parameter sets a timed fan delay after defrost for dripping. The 'FS' parameter sets a temperature threshold (detected by the evaporator probe) above which the fans remain OFF, ensuring air circulation only when the evaporator temperature is below this setpoint.
9. Power Detection
The HLVD function provides an alarm if the power supply voltage falls outside the range defined by 'vU' (upper threshold) and 'vL' (lower threshold). The 'vc' parameter enables this function. If the voltage is out of range, an alarm is triggered after the delay 'va'. The 'vr' parameter determines the system's reaction: 'n' means regulation continues, 'y' means regulation stops. When the voltage returns to normal, the alarm clears, and normal regulation resumes.
10. Front Panel Commands
Detailed descriptions of key functions and combinations are provided in Section 2.
11. Digital Inputs
The free voltage digital input is programmable via the 'iF' parameter for various functions:
- iF=do (Door Switch): Signals door status. The 'dC' parameter controls compressor and fan status when the door is open (no=normal, Fn=Fan OFF, cP=Compressor OFF, Fc=Compressor and fan OFF). If 'rd=y', regulation restarts with the door open alarm. The door alarm is enabled after a delay ('di') when the door is opened, displaying 'dA'. High and low temperature alarms are disabled when the door is open.
- iF=EA (External Alarm): An 'EA' alarm message is displayed after a delay ('di') when the digital input is activated. Outputs remain unchanged. The alarm stops when the input is deactivated.
- iF=bA (Serious Alarm): A 'CA' alarm message is displayed after a delay ('di') when the digital input is activated. All relay outputs are switched OFF. The alarm stops when the input is deactivated.
- iF=dF (Start Defrost): Initiates a defrost cycle if conditions are met. Normal regulation resumes after defrost if the digital input is disabled; otherwise, the instrument waits for the 'dd' safety time to expire.
- iF=Fn (Start Evaporator Fan): Starts the evaporator fan.
- iF=Hc (Inversion of Kind of Action): Inverts the regulation from cooling to heating or vice versa.
- iF=Au (Auxiliary): Switches the second relay ON/OFF (Only XR03CX).
Digital Input Polarity ('iP'): 'cL' (activated by closing the contact) or 'oP' (activated by opening the contact).
Digital Input Delay ('di'): Delay for EA/bA alarms or door open alarm.
12. Installation and Mounting
Instruments should be mounted on a vertical panel in a 29x71 mm hole using the provided bracket. The operating temperature range is 0-60°C. Avoid locations with strong vibrations, corrosive gases, excessive dirt, or humidity. Ensure proper air circulation through cooling holes. Probes should also be installed away from air streams and potential damage.
13. Electrical Connections
Use the screw terminal block for connections (up to 2.5 mm²). Ensure the power supply matches the instrument's requirements. Separate probe cables from power and output connections. For loads exceeding relay capacity, use an external relay.
13.1 Probes
Mount probes with the bulb upwards to prevent liquid infiltration. Position the thermostat probe away from air streams for accurate room temperature measurement. Place the defrost termination probe among the coldest evaporator fins, away from heating elements, to ensure accurate defrost termination.
14. How to Use the Hot Key
14.1 How to Program the Hot Key from the Instrument (Upload)
- Program one controller using the front keypad.
- With the controller ON, insert the Hot Key and press the '◀' key. The 'uP' message appears, followed by flashing 'En'.
- Press the SET key; 'En' stops flashing.
- Turn OFF the instrument, remove the Hot Key, and turn it ON again.
Note: 'Er' message indicates failed programming. Re-insert the Hot Key and press '◀' again, or remove the Hot Key to abort.
14.2 How to Program an Instrument Using Hot Key (Download)
- Turn OFF the instrument.
- Insert a programmed Hot Key into the 5-PIN receptacle and turn the Controller ON.
- The parameter list from the Hot Key is automatically downloaded. 'En' label appears upon successful download.
- After 10 seconds, the instrument restarts with the new parameters.
- Remove the Hot Key.
Note: 'Er' message indicates failed programming. Check Hot Key connection and data, then repeat the procedure.
15. Alarm Signalling
Alarms are indicated by specific messages and LED status.
| MESS. | CAUSE | OUTPUTS |
|---|---|---|
| "P1" | Room probe failure | Compressor output according to “Cy” and “Cn” |
| "P2" | Evaporator probe failure | Defrost end is timed |
| "HA" | Maximum temperature alarm | Outputs unchanged |
| "LA" | Minimum temperature alarm | Outputs unchanged |
| “EA” | External alarm | Outputs unchanged |
| “CA” | Serious external alarm | All outputs OFF |
| “dA” | Door Open | Compressor and fans restarts |
Alarm Recovery: Probe alarms (P1, P2) recover when the probe functions normally. Temperature alarms (HA, LA) stop when the temperature returns to normal. EA and CA alarms (with iF=bL) recover when the digital input is disabled.
16. Technical Data
Power Absorption: 3.5 VA max.
Display: 2 digits, red LED, 14.2 mm high.
Inputs: Up to 2 NTC.
Digital Input: Free voltage contact.
Relay Outputs: Compressor (8(3)A, 16(5)A, or 20(8)A @ 250Vac), Defrost/Auxiliary (8(3)A @ 250Vac), Fan (8(3)A or 5(2)A @ 250Vac).
Data Storing: Non-volatile memory (EEPROM).
Kind of Action: 1B.
Pollution Grade: 2.
Software Class: A.
Rated Impulsive Voltage: 2500V.
Overvoltage Category: II.
Operating Temperature: 0÷60 °C.
Storage Temperature: -25÷60 °C.
Relative Humidity: 20÷85% (no condensing).
Measuring and Regulation Range (NTC): -40÷110°C (-40÷230°F).
Resolution: 0.1 °C or 1°C or 1 °F (selectable).
Accuracy (ambient temp. 25°C): ±0.7 °C ±1 digit.
Default Setting Values Table:
| LABEL | DESCRIPTION | RANGE | XR01CX | XR02CX | XR03CX | XR04CX | XR06CX |
|---|---|---|---|---|---|---|---|
| Set | Setpoint | LS-US | 5.0 | 3.0 | 3.0 | -5.0 | -5.0 |
| Hy | Differential | 0.1 ÷ 25°C/ 1 ÷ 45°F | 2.0°C / 4 °F | 2.0°C / 4 °F | 2.0°C / 4 °F | 2.0°C / 4 °F | 2.0°C / 4 °F |
| LS | Minimum Setpoint | -55°C÷SET/ -67°F÷SET | -55 °C / -55°F | -55 °C / -55°F | -55 °C / -55°F | -55 °C / -55°F | -55 °C / -55°F |
| US | Maximum Setpoint | SET÷99°C/ SET÷99°F | 99 °C / 99°F | 99 °C / 99°F | 99 °C / 99°F | 99 °C / 99°F | 99 °C / 99°F |
| od | Outputs activation delay at start up | 0 ÷ 99 min | 0 | 0 | 0 | 0 | 0 |
| AC | Anti-short cycle delay | 0 ÷ 50 min | 1 | 1 | 1 | 1 | 1 |
| Cy | Compressor ON time faulty probe. Cy=0 comp. always OFF | 0 ÷ 99 min | 15 | 15 | 15 | 15 | 15 |
| Cn | Compressor OFF time faulty probe. Cn=0 comp. always active | 0 ÷ 99 min | 30 | 30 | 30 | 30 | 30 |
| CH | Kind of action | cL ÷ Ht | cL | cL | cL | _ | _ |
| CF | Measurement units: °C = Celsius; °F= Fahrenheit | °C - °F | °C / °F | °C / °F | °C / °F | °C / °F | °C / °F |
| rE | Resolution (only for °C): dE= decimal between -9.9 and 9.9°C; in= integer | dE – in | dE/ in | dE/ in | dE/ in | dE/ in | dE/ in |
| Ld | Default Display: P1= room probe; P2= evaporator probe | P1 - P2 | _ | _ | _ | P1 | P1 |
| dy | Display delay | 0 ÷ 15 min | 0 | 0 | 0 | 0 | 0 |
| ot | First probe calibration | -9.9÷9.9°C/ -17÷17°F | 0 | 0 | 0 | 0 | 0 |
| P2 | Second probe presence: n= not present; y= present | n – Y | _ | _ | _ | y | y |
| oE | Second probe calibration | -9.9÷9.9°C/ -17÷17°F | _ | _ | _ | 0 | 0 |
| td | Defrost type: EL= electrical heater, compressor OFF; in= hot gas, compressor ON | EL – in | _ | _ | _ | EL | EL |
| dE | Defrost termination temperature | -55÷50°C/ -67÷99°F | _ | _ | _ | 8.0 °C / 46 °F | 8.0 °C / 46 °F |
| id | Interval between defrost cycles | 0 ÷ 99 hours | _ | 8 | 8 | 6 | 6 |
| Md | Maximum length for defrost. when P2=n, (not evaporator probe: timed defrost) it sets the defrost duration, when P2 = y (defrost end based on temperature) it sets the maximum length for defrost. | 0 ÷ 99 min. | _ | 20 | 20 | 30 | 30 |
| dd | Start defrost delay | 0 ÷ 99 min. | _ | _ | _ | 0 | 0 |
| dF | Display during defrost: rt= real temperature; it= start defrost temperature; SP= SET-POINT; dE= label dF. | rt – it – SP – dE | _ | it | it | it | it |
| dt | Drip time | 0 ÷ 99 min | _ | _ | _ | 0 | 0 |
| dP | Defrost at power-on: y= at power on defrost starts; n= defrost doesn’t start at power-on | y - n | _ | _ | _ | n | n |
| FC | Fans operating mode: cn= in runs with the compressor, OFF during defrost; on= continuous mode, OFF during defrost; cY= runs with the compressor, ON during defrost; oY= continuous mode, ON during defrost. | cn – on – cY – oY | _ | _ | _ | on | on |
| Fd | Fans delay after defrost | 0 ÷ 99 min | _ | _ | _ | _ | 10 |
| FS | Fans stop temperature | -55÷50°C/ -67÷99°F | _ | _ | _ | _ | 2.0 °C / 36 °F |
| AU | Maximum temperature alarm | AL÷99°C / AL÷99°F | 99 °C / 99°F | 99 °C / 99°F | 99 °C / 99°F | 99 °C / 99°F | 99 °C / 99°F |
| AL | Minimum temperature alarm | -55°C÷AU/ -67°F÷AU | -55 °C / -55 °F | -55 °C / -55°F | -55 °C / -55°F | -55 °C / -55°F | -55 °C / -55°F |
| Ad | Temperature alarm delay | 0 ÷ 99 min | 15 | 15 | 15 | 15 | 15 |
| dA | Exclusion of temperature alarm at start up | 0 ÷ 99 min | 90 | 90 | 90 | 90 | 90 |
| vc | Voltage control switch | n - y | y | y | y | y | y |
| vU | Voltage upper threshold | 18 ÷ 28 V/ 9 ÷ 14 V | 25/14 | 25/14 | 25/14 | 25/14 | 25/14 |
| vL | Voltage lower threshold | 18 ÷ 28 V/ 9 ÷ 14 V | 19/9 | 19/9 | 19/9 | 19/9 | 19/9 |
| va | Voltage alarm active delay | 0÷99 sec | 60 | 60 | 60 | 60 | 60 |
| vr | Voltage regulation disabling | n - y | y | y | y | y | y |
| vd | Voltage Differential | 0 ÷ 25 V | 10 | 10 | 10 | 10 | 10 |
| o2 | The second relay configuration: nu= not use; CP= compressor ; dF=defrost; Fn=fan; AL= alarm; LG= Light; AU=auxiliary | nu - CP - dF- Fn - AL - LG- AU | _ | _ | AU | _ | _ |
| iP | Digital input polarity: oP= activated by closing the contact; cL= activated by opening the contact | cL – oP | cL | cL | cL | _ | cL |
| iF | Digital input configuration: (do/ EA/ bA/ dF/ Fn/ Hc/ Au) do= door switch function; EA= external alarm: “ EA” message is displayed; bA= serious alarm “ CA” message is displayed; dF= defrost activation; Fn=start the evaporator fan; Hc= inversion of the kind of action; Au =not used. | do – EA – bA –dF– Fn– Hc –Au | EA | EA | do | _ | do |
| di | Digital input delay: with iF=EA or bA delay between the detection of the external alarm condition and its signalling. With iF=do it represents the delay to activate the door open alarm. | 0 ÷ 99 min | 5 | 5 | 15 | _ | 15 |
| dC | Compressor and fan status when open door : no= normal ; Fn = Fans OFF; cP =Compressor OFF; Fc = Compressor and fans OFF; | no / Fn / cP / Fc | no | no | no | _ | FC |
| rd | Regulation with door open: n = no regulation if door is opened; Y= when di is elapsed regulation restarts even if door open alarm is present; | n - y | y | y | y | _ | y |
| Fr | Parameter factory reset | y - n | y | y | y | y | y |
| d1 | Thermostat probe display | Read Only | - | - | - | - | - |
| d2 | Evaporator probe display | Read Only | - | - | - | - | - |
| Pt | Parameter code table | Read Only | - | - | - | - | - |
| rL | Firmware release | Read Only | - | - | - | - | - |
Hidden Menu
The hidden menu provides access to all instrument parameters. To enter:
- Enter Programming mode (SET + ▶ for 3s).
- Release keys, then press SET + ▶ again for over 7s. The 'L2' label is displayed, followed by the 'Hy' parameter.
Parameters can be selected, viewed, and modified within this menu. To exit, press SET + ◀ or wait 15s.
Parameters can be moved between the hidden menu and the user level by pressing SET + ▶. When a parameter is in the user level, its decimal point is displayed.
