Dixell
Operating instructions
1592002910
1592002910 XH460L GB R1.0 18.05.04
XH460L
1/5
XH460L
TEMPERATURE AND HUMIDITY CONTROLLER
FOR FREEZING – PROVING CABINETS
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
The
XH460L,
38x185
format, is a microprocessor controller, designed for freezing and proving cabinets-
units. It controls both humidity and temperature. It has 6 output relays to control compressor, heating
elements, defrost, fan de-humidifier and humidifier. It has 2 NTC inputs one for thermostat the other one
for defrost. It’s also present a 4÷20mA input for humidity. There is one digital input (free contact)
configurable by parameter. An output allows the user to programme the parameter list with the
“Hot
Key”.
3.
TEMPERATURE REGULATION
The temperature regulation is performed through neutral zone using compressor and heater output
relays.
Set point
OFF
ON
•
Heating
output: CUT IN is “SET_T-dbt”, CUT OUT is when the temperature reaches the set point.
•
Compressor
output CUT IN is “ SET_T +dbt”, CUT OUT is when the temperature reaches the set point.
3.1
DEFROST
Two defrost modes are available through the “
tdF
” parameter: defrost with electrical heater or hot gas.
The defrost interval is control by means of parameter “
EdF
”: (EdF=in) the defrost is made every “
IdF
”
time, (EdF=Sd) the interval “IdF” is calculate through Smart Defrost algorithm (only when the compressor
is ON).
To
disable
the defrost set the
MdF
parameter to
zero
Humidity regulation during a defrost depends on the
Hud
parameter.
With
Hud=no
humidity regulation is disabled.
Con
Hud=yES
humidity regulation is performed also during a defrost.
4.
HUMIDITY REGULATION
The humidity regulation is performed through neutral zone, by humidifying dehumidifying actions.
Humidity control can be disabled setting the SET_RH to “nu” value. In this case only the temperature
control is perform.
4.1
HUMIDIFYING ACTION
The humidifying action is done enabling the humidifier relay when the humidity is lower than the
“SET_RH-dbH” value.
The relay is switch off when humidity reaches the set values.
4.2
DEHUMIDIFYING ACTION WITHOUT DEHUMIDIFIER RELAY (OA1 DIFFERENT FROM DEH) -
STANDARD
In this case the dehumidifying action is performed by setting the following parameters in this way:
tHu = c-H kind of dehumidifying by means of heating and compressor relays
oA1 different from dEH:
The heating and compressor outputs are activated together when humidity is higher than dbH
value. Outputs are disabled when humidity comes back to the SET_RH value.
4.2.1 Relation between cooling, heating and dehumidifying
1.
If is simultaneously present a request of cooling (temp>SET_T+dbt) and dehumidifying (RH >
dbH): the cooling action has the priority over the dehumidifying action: only the
compressor relay is energised till the SET_T is reached at this point also the heating relay is
enabled.
2.
If is simultaneously present a request of heating (temp< SET_T-dbt) and dehumidifying (RH >
dbH): the dehumidifying action has the priority over the heating action: both the
compressor and the heating relays are energised till the humidity set is reached at this point only
the heating relay is enabled.
4.3
DEHUMIDIFYING ACTION WITH DEHUMIDIFIER RELAY (OA1 = DEH)
The configurable relay is used,
(XH460L terminals 3-4)
setting the parameter
oA1 =dEH.
NOTE:
the LIGHT button is not more available;
Two kinds of de-humidifying are available:
4.3.1 Dehumidifying action with ONLY de-humidifier relay
By setting the parameter
tHu
=
db
the de-humidifying action is performed by enabling the de-humidifier
relay when the humidity is higher than SET_RH
+ dbH.
The relay is switch off when humidity comes back to the SET_RH value.
4.3.2 Dehumidifying action with de-humidifier and compressor relays
By setting the parameter
tHu
=
cHu
the de-humidifying action is performed by enabling the de-humidifier
and compressor relays together. when the humidity is higher than SET_RH
+ dbH.
The relays are switched off when humidity comes back to the SET_RH value.
If is simultaneously present a request of cooling (temp>SET_T+dbt) and dehumidifying (RH >
dbH): the cooling action has the priority over the dehumidifying action: only the compressor
relay is energised till the SET_T is reached at this point also the de-humidifier is enabled.
5.
FA NS
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 continuously, but not during defrost
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
6.
FREZING –PROVING CYCLE
FREEZING
PROVING
HOLDING
(optional)
The diagrams displays a typical freezing and proving cycle with the holding phase.
FREEZING PHASE
lasts for the T1 time, usually without humidity control
PROVING PHASE
lasts for the T2 time, both temperature and humidity are controlled.
The end of the proving phase is signalled by the internal buzzer and by the “End” message on the
display.
After
the
PROVING PHASE
the behaviour of the controller depends on the parameter
trc,
according to
the following settings:
trc
=
co
controller maintains the set points of the proving phase (
HOLDING)
trc
=
in
controller stop the regulation at all.
trc
=
cL
controller performs the freezing and proving phase till is stopped manually.
trc
=
cLE
as (
trc
=
cL
) plus at the end of each cycle the
End
label is displayed and the buzzer
is switched on.
6.1
HOW TO SET THE DURATION OF THE FREEZING AND PROVING CYCLE
1.
Push the
CLOCK
key, the display shows on the bottom display the “tM1” message, while the
“hourglass” start flashing.
2.
Push again the
CLOCK
the duration of the freezing phase is shown, hh:mm.
3.
To set the duration push the
UP
and
DOWN
keys.
4.
Push again the
CLOCK
to confirm the time and pass to the setting of the proving phase: the “tM2”
message is displayed.
5.
Push the
CLOCK
key to see its duration and use the
UP
and
DOWN
keys to set it.
6.
Confirm the value by pushing again the
CLOCK
key and pass to the humidity display.
NOTE:
If the phase length is modified during a cycle, the modification is performed also in the next cycle.
6.2
HOW TO SET THE TARGET HUMIDITY OF THE FREEZING AND PROVING CYCLE
1.
Push the
SET_RH
key, the display shows on the bottom display the “SH1” message, while the “set
” icon starts flashing.
2.
Push again the
SET_RH
the humidity set point of the freezing phase is shown. Set it using the
UP
and
DOWN
keys. To
disable
the humidity control during the freezing phase set it to “
nu
”.
3.
Push again the
SET_RH
to confirm the value and pass to the setting of the proving phase: the
“SH2” message is displayed.
4.
Push the
SET_RH
key to see its value and use the
UP
and
DOWN
keys to set it.
