Dixell
Installing and Operating Instructions
rel.1.0 –07/03/2002 - cod.
1592013010
1592013010 XM470K GB
XM470K
1/6
XM470K
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
SAF
E
TY 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 XM470K is microprocessor based controllers suitable for applications on medium or low
temperature multiplexed cabinets made of up to 5 units. It can be inserted in a LAN of up to 5 different
sections which can operate, depending on the programming, as stand alone controllers or following the
commands coming from one of the other sections. XM470K is provided with five relay outputs to control
the solenoid valve, defrost - which can be either electrical or hot gas - the evaporator fans, the lights,
and an auxiliary output. They are also provided with three NTC probe inputs, one for temperature
control, one to control the defrost end temperature of the evaporator and the third, optional, for the
display. There are two digital inputs (free contact) one for the start of an energy saving cycle and one
fully configurable by parameter.
Two LAN output allows an easy connection between the controllers and a TTL connector for quick
programming by means of an Hot Key is also available. Direct serial output RS485 ModBUS-RTU
compatible and internal RTC are available as options.
3.
CONTROLLING LOADS
3.1
THE SOLENOID VALVE
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 solenoid valve is opened and then closed when the temperature reaches the set point value again.
In case of fault in the thermostat probe the opening and closing of the solenoid valve are timed through
parameters “COn” and “COF”.
3.2
DEFROST
Two defrost modes are available through the “tdF” parameter: defrost with electrical heater and hot gas
defrost. The defrost interval is control by means of parameter “EdF”: (EdF = rtc) the defrost is made in
real time depending on the hours set in the parameters Ld1..Ld8 on workdays and in Sd1…Sd8 in
holidays; (EdF = in) the defrost is made every “IdF” time, (EdF=Sd) the interval “IdF” is calculate through
Smart Defrost algorithm (only when the SOLENOID VALVE is ON and the evaporator temperature is
bigger than “SdF” parameter).
At the end of defrost the drip time is controlled through the “Fdt” parameter.
The starting of a defrost cycle can be operated locally (manual activation by means of the keyboard or
digital input or end of interval time) or the command can come from the Master defrost unit of the LAN.
In this case the controller will operate the defrost cycle following the parameters it has programmed but,
at the end of the drip time, will wait that all the other controllers of the LAN finish their defrost cycle
before to re-start the normal regulation of the temperature.
Every time any of the controller of the LAN begin a defrost cycle it issue the command into the network
making all the other controllers start their own cycle. This allows a perfect synchronisation of the defrost
in the whole multiplexed cabinet
3.3
CONTROL OF EVAPORATOR FANS
The fan control mode is selected by means of the “FnC” parameter:
C-n = running with the solenoid valve, OFF during the defrost;
C-y = running with the solenoid valve, ON during the defrost;
O-n = continuous mode, OFF during the defrost;
O-y = continuous mode, ON during the defrost;
An additional parameter “FSt” provides the setting of temperature, detected by the evaporator probe,
above which the fans are always OFF. This can be used to make sure circulation of air only if his
temperature is lower than set in “FSt”.
3.4
AUXILIARY OUTPUT
The auxiliary output is switch ON and OFF by means of the corresponding button on the keyboard.
4.
KEYBOARDS
There are two kind of keyboard available for the XM470K controller:.
T840: 8 Keys, horizontal shape (185x38mm).
V840: 8 Keys, vertical shape (64x100mm).
To display and modify target set point; in programming mode it selects a parameter or
confirm an operation.
By holding it pressed for 3s when max or min temperature is displayed it will be erased.
By pressing it when the current time is displayed, it allows the User to re-set the current time
and three holidays.
To see the max. stored temperature; in programming mode it browses the parameter codes
or increases the displayed value.
By holding it pressed for 3s the give access to the “Section” menù.
To see the min stored temperature; in programming mode it browses the parameter codes or
decreases the displayed value.
By holding it pressed for 3s the current time is displayed and it permits the User to enter
Energy saving, Defrost and Clock parameter menu.
By holding it pressed for 3s the defrost is started.
By pressing it when the current time is displayed, it allows the User to set defrost times.
Switch ON and OFF the cold room light.
By holding it pressed for 3s Energy Saving function is started or stopped.
By holding it pressed for 6s, the Holiday function is started or stopped.
By pressing it when the current time is displayed, it allows the User to set Energy Saving
times.
Switch ON and OFF the auxiliary output.
Switch ON and OFF the instrument.
KEY COMBINATIONS
+
To lock and unlock the keyboard.
+
To enter the programming mode.
+
To exit the programming mode.
4.1
USE OF LEDS
Each LED function is described in the following table.
LED
MODE
Function
ON
The SOLENOID VALVE is running
FLASHING - Programming Phase (flashing with LED
)
- Anti-short cycle delay enabled
