dixell XR20CX - User Manual

 
Installing and Operating Instructions
1592020022
1592020022 XR20CX GB ES m&M r1.1 05.03.2007.doc XR20CX 1/4
Digital controller with off cycle defrost
XR20CX
CONTENTS
1.
GENERAL WARNING ___________________________________________________1
2. GENERAL DESCRIPTION _______________________________________________1
3. CONTROLLING LOADS _________________________________________________1
4. FRONT PANEL COMMANDS_____________________________________________1
5. MAX & MIN TEMPERATURE MEMORIZATION_______________________________1
6. MAIN FUNCTIONS _____________________________________________________1
7. PARAMETERS ________________________________________________________2
8. DIGITAL INPUT________________________________________________________3
9. TTL SERIAL LINE – FOR MONITORING SYSTEMS ___________________________3
10. X-REP OUTPUT – OPTIONAL ____________________________________________3
11. INSTALLATION AND MOUNTING _________________________________________3
12. ELECTRICAL CONNECTIONS____________________________________________3
13. HOW TO USE THE HOT KEY_____________________________________________3
14. ALARM SIGNALS ______________________________________________________3
15. TECHNICAL DATA _____________________________________________________3
16. CONNECTIONS _______________________________________________________4
17. DEFAULT SETTING VALUES_____________________________________________4
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 XR20C, format 32 x 74 mm, is a digital thermostat with off cycle defrost designed for
refrigeration applications at normal temperature. It provides a relay output to drive the
compressor. It is also provided with 2 NTC or PTC probe inputs, the first one for temperature
control, the second one, optional, to connect to the HOT KEY terminals to signal the
condenser temperature alarm or to display a temperature. The digital input can operate as
third temperature probe.
The HOT KEY output allows to connect the unit, by means of the external module XJ485-CX,
to a network line ModBUS-RTU compatible such as the monitoring units of X-WEB
family. It allows to program the controller by means the HOT KEY programming keyboard.
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.
Time
Temper.
Compr.
SET
ON
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 parameter “MdF”.
4. FRONT PANEL COMMANDS
: 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.
(DOWN) To see the min stored temperature; in programming mode it browses the
parameter codes or decreases the displayed value.
To activate / deactivate the energy saving cycle.
Not enabled
KEY COMBINATIONS:
+

To lock & unlock the keyboard.
+ To enter in programming mode.
+  To return to the room temperature display.
4.1 USE OF LEDS
Each LED function is described in the following table.
LED MODE FUNCTION
ON Compressor enabled
Flashing Anti-short cycle delay enabled
ON Defrost enabled
ON An alarm is occurring
ON Continuous cycle is running
ON Energy saving enabled
°C/°F
ON Measurement unit
°C/°F
Flashing Programming phase
5. MAX & MIN TEMPERATURE MEMORIZATION
5.1 HOW TO SEE THE MIN TEMPERATURE
1. Press and release the 8 key.
2. The “Lo” message will be displayed followed by the minimum temperature recorded.
3. By pressing the 8 key again or by waiting 5s the normal display will be restored.
5.2 HOW TO SEE THE MAX TEMPERATURE
1. Press and release the 9 key.
2. The “Hi” message will be displayed followed by the maximum temperature recorded.
3. By pressing the 9 key again or by waiting 5s the normal display will be restored.
5.3 HOW TO RESET THE MAX AND MIN TEMPERATURE RECORDED
1. Hold press the SET key for more than 3s, while the max. or min temperature is
displayed. (rSt message will be displayed)
2. To confirm the operation the “rSt” message starts blinking and the normal temperature
will be displayed.
6. MAIN FUNCTIONS
6.1 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.
6.2 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 “°C” or “°F” LED starts blinking;
3. To change the Set value push the 9or 8 arrows within 10s.
4. To memorise the new set point value push the SET key again or wait 10s.
6.3 HOW TO START A MANUAL DEFROST
Push the DEF key for more than 2 seconds and a manual defrost will
start.

Summary

General Warning and Safety Precautions

Read Before Use

Important notes for safe and correct usage of the instrument, keeping the manual accessible.

Safety Precautions

Critical safety measures including voltage checks, avoiding moisture, and disconnecting power before maintenance.

General Description and Controls

Product Overview

Details the XR20CX digital thermostat's format, features, and primary applications in refrigeration.

Front Panel Commands

Explains the function of front panel buttons (SET, DEF, UP, DOWN) and LEDs for operation.

Core Functions: Loads, Setpoint, and Defrost

Controlling Loads

Describes how the thermostat manages the compressor based on temperature differentials.

Setpoint Management

Instructions on viewing and changing the temperature setpoint and initiating manual defrost.

Temperature Monitoring and Main Functions

Max & Min Temperature

Procedures to view and reset the maximum and minimum recorded temperatures.

Main Functions Overview

Guides on viewing and modifying the setpoint and starting a manual defrost cycle.

Parameter Configuration

Regulation and Display Parameters

Details parameters for temperature regulation, probe calibration, and display settings.

Defrost and Alarm Parameters

Configuration settings for defrost cycles, temperature alarms, and delays.

Digital Input and Connectivity

Parameters for digital input functions, serial line, and optional outputs.

Digital Input Functions and Operations

Specific Digital Input Modes

Configuring digital inputs for door switch, alarms, pressure switch, defrost, and mode inversion.

Energy Saving and Polarity

Enabling energy saving mode and setting digital input polarity (open/close contact).

Installation, Connections, and Hot Key Usage

Installation and Electrical

Guidelines for mounting the unit and making electrical connections safely.

Hot Key Programming

Instructions for uploading configuration to the Hot Key and downloading from it.

Alarm Signals, Messages, and Technical Data

Alarm Recovery and Messages

Details on how alarms are signaled, recover, and explains other instrument messages.

Technical Data

Comprehensive technical specifications including housing, power, and environmental ratings.

Connections and Default Settings

Wiring Diagrams

Specific connection diagrams for 8A and 20A compressor models.

Default Setting Values

A table listing all parameters with their default values for easy reference.

dixell XR20CX Specifications

General

Control Type	ON/OFF
Storage Temperature	-30 to 85°C
Resolution	0.1°C
Accuracy	±0.5°C
Front Panel Protection	IP65
Power Consumption	3VA max
Protection Rating	IP20
Weight	Approx. 100g
Power Supply	230Vac ±10%
Inputs	1 NTC sensor
Display	LED
Relative Humidity	20 to 85% (non-condensing)
Dimensions	32 x 74 x 60 mm