dixell XH460L Operating Instructions

Dixell
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.
ON
OFF
• 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 SET_RH+dbH
value. Outputs are disabled when humidity comes back to the SET_RH value.
1592002910 XH460L GB R1.0 18.05.04
Operating instructions
Set point

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 >
SET_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 >
SET_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 >
SET_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
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.
XH460L
1592002910
PROVING HOLDING
(optional)
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