Dixell
Installing and Operating Instructions
rel.1.0 –07/03/2002 - cod.
1592013000
1592013000 XM440_460K GB
XM440K & XM460K
1/1
XM440K
XM460K
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.
2.
GENERAL DESCRIPTION
Models XM440K and XM460K are microprocessor based controllers suitable for applications on
medium or low temperature multiplexed cabinets made of up to 5 units. They 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. XM440K is provided with
3 relay outputs to control the solenoid valve, defrost - which can be either electrical or hot gas and the
lights while XM460K is also provided with a relay output to control the evaporator fans. 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 devoted to the Energy saving activation and the other configurable by means of
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 (XM460K)
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”.
4.
KEYBOARDS
There are 3 kind of keyboard available for the XM440K and XM460K controller:
T640: 6 Keys, horizontal shape (185x38mm).
V640: 6 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.
Only C443 keyboard
By holding it pressed for 5s set the instrument in Stand By
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.
Only T640 and V640 keyboards
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.
Only C443 keyboard
By holding it pressed for 3s the defrost is started.
Only T640 and V640 keyboards
Switch ON and OFF the instrument.
KEY COMBINATIONS
+
+
To lock and unlock the keyboard.
+
+
To enter the programming mode.
C443: 4 Keys, horizontal shape
