Emerson Dixell XRi77CX Installing And Operating Instructions

Digital controller for variable speed compressors
XRi77CX
1. GENERAL WARNING............................................................................................................................. 1
2. GENERAL DESCRIPTION..................................................................................................................... 1
3. CONTROLLING LOADS......................................................................................................................... 1
4. VARIABLE SPEED COMPRESSOR CONTROL ............................................................................... 1
5. PULL DOWN ............................................................................................................................................ 2
6. DUAL MAP FEATURE .........................................................ERROR! BOOKMARK NOT DEFINED.
7. FRONT PANEL COMMANDS ............................................................................................................... 2
8. MAX & MIN TEMPERATURE MEMORIZATION ................................................................................ 2
9. MAIN FUNCTIONS.................................................................................................................................. 2
10. PARAMETERS ........................................................................................................................................ 3
11. DIGITAL INPUTS ..................................................................................................................................... 4
12. RS485 SERIAL LINE – FOR MONITORING SYSTEMS .................................................................. 5
13. INSTALLATION AND MOUNTING ....................................................................................................... 5
14. ELECTRICAL CONNECTIONS ............................................................................................................. 5
15. HOW TO USE THE HOT KEY............................................................................................................... 5
16. ALARM SIGNALS .................................................................................................................................... 5
17. TECHNICAL DATA.................................................................................................................................. 5
18. WIRINGS .................................................................................................................................................. 5
19. 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 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.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 XRi77CX, 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 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 an 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
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.
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.
-
EdF=rtC: the defrost is real time controlled, depending on the hours set in the parameters
-
Ld1...Ld6 (for workdays).
Other parameters are used to control defrosting cycles: the maximum length (MdF) and defrosting
modes: timed or controlled by the evaporator's probe (P2P).
RNC-2014-034 XRi77CX GB r1.0 07.03.2014.docx
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 CYCLIC 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 RELAY CONFIGURATION (PAR. oA0, oA1, oA2, oA3)
The functioning of the configurable relays (terminals 1-2 and 1-7-8) can be set by the oA1 and oA2
parameters, according to the kind of application. In the following paragraph the possible setting:
3.4.1 LIGHT RELAY
With oAx=LiG the related relay operates as light output.
3.4.2 AUXILIARY RELAY
Relay activation by digital input 1 or digital input 2 (oAx=AUS, i1F or i2F=AUS): with oAx=AUS
and i1F, i2F=AUS the AUX relay is switched on and off by digital inputs.
3.4.3 ON/OFF RELAY (OAX = ONF)
When oAx=onF, the related 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 oAx=db the related relay can control a heater element to perform a neutral zone action.
oAx cut in = SET-HY

 oAx cut out = SET
3.4.5 ALARM RELAY
With oAx=Alr the related relay 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 stay on until the alarm condition recovers.
3.4.6 SECOND COMPRESSOR
If oAx=CP2, it will work as second compressor output. The anti-short cycle parameter AC1 gives the
possibility to desynchronize the compressor activations.
3.4.7 SECOND DEFROST OUTPUT
If oAx=dF2, it will work as second defrost output.
NOTE: It is also possible to manage 2 different and independent defrost by using special parameter
map. Please refer to Dixell to activate this function.
3.4.8 NIGHT BLIND MANAGEMENT DURING ENERGY SAVING CYCLES
With oAx=HES, the related relay operates to manage the night blind: the relay is energised when the
energy saving cycle is activated by digital input or frontal button.
3.4.9 HEATER FOR WATER DRIPPING
If oAx=Het, the related output will work as heater for water dripping during and after any defrost.
3.4.10 REGULATION OUTPUT
If oAx=inV, the related output will work as regulation output and will stay active as soon as the
regulation request is running.
4. VARIABLE SPEED COMPRESSOR CONTROL
The controller is able to drive variable speed compressor with frequency control input. The HOTKEY
port is able to issue a frequency signal from 30 to 200Hz, duty cycle=50%. A special cable (CAB-
KXV1) is used to connect the frequency output of the controller to the frequency input of the
compressor. One of the available relays can be set as oAx=inV in order to control the condenser
fan. In this case the fans will be activated only when the regulation is running.
NOTE: in case of using an inverter compressor, it must be controlled ONLY from the frequency
output. DO NOT USE ANY RELAY TO CONTROL THE COMPRESSOR POWER SUPPLY.
4.1 CABLE FOR FREQUENCY OUTPUT
CAB/KXV1
4.2 PARAMETERS
The following parameters are used to set the regulation:
HY1 Differential for proportional band: (0.1 to 25.5°C; 1 to 45°F)
PMi Lower speed limit (in percentage): (0 to PMA)
PMA Upper speed limit (in percentage): (Pmi to 100%)
XR77CX
The wiring polarity follows:
WHITE  GND (-)
GREEN  FREQ (+)
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