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Digital controller with off cycle defrost and auxiliary
XW20LR –XW20LRH
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.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.
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 XW20LR, XW20LRH, format 38x185mm, is a digital thermostat with off cycle defrost designed
for refrigeration applications at medium and low temperature. It has 2 relay outputs, one to control
compressor and the other (configurable) to control light, auxiliary or alarm. 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 three NTC or PTC probe inputs, the first one for temperature control, the second
one, to be located onto the evaporator and to control the defrost termination temperature. The third
probe is used to signal the condenser temperature alarm or to display a temperature. One of the 2
digital inputs can operate as fourth probe input.
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
Defrost is performed through a simple stop of the compressor. 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).
3.3 AUXILIARY RELAY CONFIGURATION - TERM.5-6/7, PAR. OA1
The functioning of the auxiliary relay (terminals. 5-6/7) can be set by the oA1 parameter, according to
the kind of application. In the following paragraph the possible setting:
3.3.1 Light relay - oA1= Lig
With oA1 = Lig, the 5-6/7 relay is set as light. It is activated by key or when i1F = dor.
3.3.2 Alarm relay - oA1= AUS
There are 2 possibilities:
a.
Activation via digital input (oA1 = AUS, i1F or i2F = AUS)
With oA1 = AUS and i2F or i1F = AUS the relay 5-6/7 is activated via digital input and remains ON
until the digital input is activated or is silenced by pressing any key.
b.
Auxiliary thermostat (es. anti-sweat heaters)
Parameters involved:
- ACH Type of regulation: heating/cooling;
- SAA Set point auxiliary relay
1592027520 XW20LR XW20LRH RTC GB r2.0 14.02.2014.docx
relay
Temper.
SET
Compr.
ON
- 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.
NOTE: Set oA1 =AUS and ArP= nP (no probe for auxiliary output).
In this case the relay 5-6/7 can be activated only by digital input with i1F or i2F = AUS.
3.3.3 On/off relay – oA1 = onF
In this case the relay is activated when the controller is turned on and de-activated when the controller
is in stand-by mode.
3.3.4 Neutral zone regulation
With oA1 = db the relay 5-6/7 can control a heater element to perform a neutral zone action.
oA1 cut in = SET-HY
oA1 cut out = SET
3.3.5 Second compressor
With oA1 = CP2, the relay 5-6/7 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 relays are
switched off at the same time.
3.3.6 Alarm relay
With oA1 = ALr the relay 5-6/7 operates as alarm relay. It is activated every time an alarm happens.
Its status depends on the tbA parameter:
With "tbA = y", the relay is silenced by pressing any key.
With "tbA = n", the alarm relay remains on until the alarm condition recovers.
3.3.7 Night blind management during energy saving cycles
With oA1 = HES, the relay 5-6/7 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
4.1 XW20LR:STANDARD FRONTAL PANEL
4.2 XW20LR: STEEL FINISHING
4.1 XW20LRH
Time
: 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 switch the instrument off, if onF = oFF.
To switch the light, if oA1 = Lig.
KEY COMBINATIONS:
+
+
+
4.2 USE OF LEDS
Each LED function is described in the following table.
LED
MODE
ON
Compressor enabled
Flashing Anti-short cycle delay enabled
XW20LR – XW20LRH
To lock & unlock the keyboard.
To enter in programming mode.
To return to the room temperature display.
FUNCTION
1/5
Related Manuals for Emerson dixell XW20LR
Summary of Contents for Emerson dixell XW20LR
- Page 1 - SHy Differential for auxiliary relay - ArP Probe for auxiliary relay Digital controller with off cycle defrost and auxiliary - Sdd Auxiliary output off during defrost relay By means of these 5 parameters the functioning of the auxiliary relay can be set. XW20LR –XW20LRH NOTE: Set oA1 =AUS and ArP= nP (no probe for auxiliary output).
-
Page 2: Max & Min Temperature Memorization
6.6.2 HOW TO MOVE A PARAMETER FROM THE HIDDEN MENU TO THE MODE FUNCTION FIRST LEVEL AND VICEVERSA. Defrost enabled Each parameter present in the HIDDEN MENU can be removed or put into “THE FIRST LEVEL” (user Flashing Drip time in progress level) by pressing “SET + n ”. -
Page 3: Digital Inputs
dtE Defrost termination temperature: (-50÷50 °C/ -58÷122°F) (Enabled only when EdF=Pb) sets If the nPS activation in the did time is reached, switch off and on the instrument to the temperature measured by the evaporator probe, which causes the end of defrost. restart normal regulation. -
Page 4: Installation And Mounting
8.8 HOLIDAY DEFROST (i1F or i2F = HDF) –ONLY FOR MODELS WITH RTC 13. HOW TO USE THE HOT KEY This function enabled the holiday defrost setting. 13.1 HOW TO PROGRAM A HOT KEY FROM THE INSTRUMENT (UPLOAD) 8.9 ON OFF FUNCTION (i1F or i2F = onF) Program one controller with the front keypad. -
Page 5: Default Setting Values
16. CONNECTIONS Label Name Range Value Level ILE* Energy Saving cycle start during workdays 0 ÷ 23h5 dLE* Energy Saving cycle length during workdays 0 ÷ 24h0 ISE* Energy Saving cycle start on holidays 0 ÷ 23h5 dSE* Energy Saving cycle length on holidays 0 ÷...