Dixell Temperature Controller - Selecta STOCKLOW LT Manual De Instrucciones

MANUAL DE INSTRUCCIONES
Digital controller for medium-low temperature
refrigeration applications
XW70LH
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.
Dixell Srl reserves the right to change the composition of its products, even without notice, ensuring the

same and unchanged functionality.
2. GENERAL DESCRIPTION
Model XW70LH, format 38x185mm, is microprocessor based controller, suitable for applications on
medium or low temperature ventilated refrigerating units. It has five relay outputs to control
compressor, fan, defrost, which can be either electrical or reverse cycle (hot gas) and light. The last
one can be used as auxiliary output or for alarm signalling. It could be provided with a Real Time
Clock which allows programming of up to 6 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 or PTC probe inputs, the first one for temperature control, the second one, to be
located onto the evaporator, to control the defrost termination temperature and to managed the fan.
One of the 2 digital inputs can operate as third temperature probe. The fourth probe is used to signal
the condenser temperature alarm or to display a temperature.
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 dIXEL 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.
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). If the RTC is present is controlled
by means of parameter "EdF":
with EdF=in the defrost is made every "IdF" time – standard way for controller without RTC.
-
with EdF = "rtc", the defrost is made in real time depending on the hours set in the parameters
-
Ld1..Ld6 on workdays and in Sd1...Sd6 in holidays;
Other parameters are used to control defrost cycles: 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 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.
1592036010 XW70LH GB r1.0 14.02.2014.docx
J
.P. SELECTA s.a.u.

7. Dixell temperature controller

Changing parameters may affect the correct operation of the equipment.
DO NOT modify the parameters if you are not completely sure.
Temper.
SET
Compr.
ON
Autovía A-2 Km 585.1 Abrera 08630 (Barcelona) España
e-mail: selecta@jpselecta.es - website: http://www.grupo-selecta.com
CÓDIGO 80412 REV 0
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.
3.3.2 Cyclical activation of the fans with compressor off.
When Fnc = c-n or c-Y (fans in parallel to 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, when the
compressor is off.
3.4 AUXILIARY OUTPUT CONFIGURATION
The functioning of the auxiliary relay (terminals. 20-21) can be set by the oA4 parameter, according
to the kind of application. In the following paragraph the possible setting:
3.4.1 oA4 = AUS: Auxiliary thermostat
I.E.. anti condensing heater) with the possibility of switching it on and off also by 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
By means of these 5 parameters the functioning of the auxiliary relay can be set.. The differential is
given by the SHy parameter.
The auxiliary relay can be switched on also by the AUX button. In this case it remains on till it's
manually switched off.
NOTE: Set Oa4 =AUS and ArP= nP (no probe for auxiliary output).
In this case the relay 20-21 can be activated only by pushing the AUX button of the keyboard.
3.4.2 oA4 = onF: On/off relay
In this case the relay is activated when the controller is turned on and de-activated when the controller
is turned off.
3.4.3 oA4 = db: Neutral zone regulation
With oA4 = db the relay 20-21 can control a heater element to perform a neutral zone action.
oA4 cut in = SET-HY
oA4 cut out = SET
3.4.4 oA4 = CP2: Second compressor
With oA4 = CP2, the relay 20-21 operates as second compressor: it 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.
3.4.5 oA4 = ALr: Alarm relay
With oA4 = ALr the relay 20-21 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 oA4 = HES: Night blind management during energy saving cycles
With oA4 = HES, the relay 20-21 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
Time
Pour afficher et modifier le point de consigne. Dans le mode programmation, permet de
sélectionner un paramètre ou de confirmer une opération.
Pour démarrer un dégivrage.
Pour afficher la température maximale enregistrée. Dans le mode programmation, permet
de naviguer dans la liste des paramètres ou d'augmenter la valeur affichée.
Pour afficher la température minimale enregistrée. Dans le mode programmation, permet
de naviguer dans la liste des paramètres ou de diminuer la valeur affichée.
Allume et éteint l'appareil, quand onF= oFF.
Allume et éteint la lumière, quand oA3= Lig.
To switch the auxiliary relay, with oA3 or oA4 = AUS
AUX
To switch the auxiliary relay, with oA3 or oA4 = AUS
KEY COMBINATIONS:
+

+
+
4.1 USE OF LEDS
Each LED function is described in the following table.
LED MODE
ON Compressor enabled
Flashing Anti-short cycle delay enabled
XW70LH
03/2021
To lock & unlock the keyboard.
To enter in programming mode.
To return to the room temperature display.
FUNCTION
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