Emerson dixell XR70D Installing And Operating Instructions

Digital controller with defrost and fans management
XR70C– XR70D – XR72C
CONTENTS
1. GENERAL WARNING ___________________________________________ 1
2. GENERAL DESCRIPTION _______________________________________ 1
3. CONTROLLING LOADS _________________________________________ 1
4. FRONT PANEL COMMANDS _____________________________________ 1
5. TEMPERATURE ALARM AND ITS DURATION RECORDING (HACCP) ___ 1
6. MAIN FUNCTIONS _____________________________________________ 2
7. PARAMETERS ________________________________________________ 2
8. DIGITAL INPUT ________________________________________________ 3
9. INSTALLATION AND MOUNTING _________________________________ 3
10. ELECTRICAL CONNECTIONS ____________________________________ 3
11. HOW TO USE THE HOT KEY_____________________________________ 3
12. ALARM SIGNALS ______________________________________________ 3
13. TECHNICAL DATA _____________________________________________ 4
14. CONNECTIONS _______________________________________________ 4
15. 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.
• 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
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
Models XR70C and XR72C, 32x74 mm format, and XR70D, DIN rail format, are a
microprocessor based controllers, suitable for applications on medium or low
temperature ventilated refrigerating units. They have three relay outputs to control
compressor, fan, and defrost, which can be either electrical or reverse cycle (hot
gas). XR70C and XR70D have a fourth relay for alarms signalling. XR72C has a
fourth relay to pilot a second compressor.
They are also provided with two NTC or PTC probe inputs, one for temperature
control, the other, to be located onto the evaporator, to control the defrost
termination temperature and to managed the fan. The instrument is fully
configurable through special parameters that can be easily programmed through
the keyboard.
3. CONTROLLING LOADS
3.1 COMPRESSOR
In case of fault in the thermostat probe the start and stop of the compressor are
timed through parameters "COn" and "COF".
ND
3.2 2 COMPRESSOR MANAGEMENT – XR72C ONLY
The relay of the second compressor is activated in parallel with the relay of the first
compressor, with a possible delay set in the AC1 parameter. Both the
compressors are switched off at the same time.
1592007261 XR70C-D XR72C GB r1.0 25.08.2014
connections before any kind
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.
XR70C – XR70D - XR72C
3.3 DEFROST
Two defrost modes are available through the "tdF" parameter: defrost through
electrical heater (tdF = EL) and hot gas defrost (tdF = in). Other parameters are
used to control the interval between defrost cycles (IdF), its maximum length (MdF)
and two defrost 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 FSt parameter.
With FSt =0 the dripping time is disabled.
3.4 CONTROL OF EVAPORATOR FANS
The fan control mode is selected by means of the "FnC" parameter:
FnC = C_n:
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
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".
3.4.1 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.
Functioning: if the difference of temperature between the evaporator and the
room probes is more than the value of the Fct parameter, the fans are switched on.
With Fct=0 the function is disabled.
4. FRONT PANEL COMMANDS
of
XR70C – XR72C
SET: To display target set point; in programming mode it selects a parameter or
confirm an operation.
(DEF) To start a manual defrost
o (UP): To see the last temperature alarm happened; in programming mode it
browses the parameter codes or increases the displayed value.
n (DOWN) To see the last temperature alarm happened; in programming mode it
browses the parameter codes or decreases the displayed value.
KEY COMBINATIONS:
o + n To lock & unlock the keyboard.
SET + n To enter in programming mode.
SET + o To return to the room temperature display.
4.1 USE OF LEDS
Each LED function is described in the following table.
LED MODE
ON Compressor enabled
Flashing
-Programming Phase (flashing with
- Anti-short cycle delay enabled
ON Defrost enabled
Flashing
- Programming Phase (flashing with
- Drip time in progress
ON Fans enabled
Flashing Fans delay after defrost in progress.
ON An temperature alarm happened
5. TEMPERATURE ALARM AND ITS DURATION
RECORDING (HACCP)
Instruments signal
and record
temperature alarms,
together with their
duration and max
value reached. See
drawing:
fans will switch ON and OFF with the compressor and not
fans will switch ON and OFF with the compressor and run
FUNCTION
)
Ex. High temperature alarm
Temperature
Max
X
Temperature
ALu
X
High temp. alarm
Safe food zone
Set
ALL
Low temp. alarm
Alarm duration
XR70D
)
X
Time
1/4