1592034020 XR77CHC EN r1.0 2019.01.31
XR77CHC
2/7
8
CONDENSER FAN
8.1
GENERAL DESCRIPTION
The condenser fan is can be managed by dedicated control. To enable it, a condenser probe must be
selected by using par.
FAC
. Here follows the description of all the related parameters:
•
FAC
: to select the condenser fan probe
•
St2
: to select the condenser fan deactivation setpoint
•
HY2
: differential for condenser fan activation
•
FCC
parameter it can be selected the condenser fan working mode:
o
FCC=C-n:
condenser fan will switch ON and OFF with the compressor and
will
not run during defrost
o
FCC =o-n:
condenser fan will run even if the compressor is off, and will not run
during defrost
o
FCC =C-Y:
condenser fan will switch ON and OFF with the compressor and will
run during defrost
o
FCC =o-Y:
condenser fan will run continuously, also during defrost.
9
DEFROST
Two defrost modes are available through the
tdF
parameter: defrost through electrical heater
(
tdF=EL
) and hot gas defrost (
tdF=in
).
The defrost interval depends on the presence of the RTC (optional). The internal RTC is controlled by means
of the
EdF
parameter:
•
EdF=in:
the defrost is made every
idF
time
–
standard way for controller without RTC.
•
EdF=rtC:
the defrost is real time controlled, depending on the day enabled in the parameters
dd1
…
dd7
and the hours set in the parameters
Ld1...Ld6
.
Other parameters are used to control defrosting cycles: the maximum length (
MdF
) and defrosting modes:
timed or controlled by the evaporator’s
probe (
P2P
).
•
At the end of defrost dripping time is started, its length is set in the
Fdt
parameter. With
Fdt=0
the
dripping time is disabled.
9.1
SYNCHRONIZED DEFROST
This defrost function requires:
-
To set a digital input of any controller as
ixF=dEF
-
To connect (by wire) all digital inputs set as
ixF=dEF
A maximum number of 20 controllers can be used in this configuration.
The Synchronized defrost mode is enabled by par.
SYd=SYn
. After any defrost request (received by RTC,
timed by par.
idF,
manually by defrost button or by digital input set as dEF), all controllers will activate their
own defrost phase. When a controller ends its proper defrost phase, it releases the defrost line and load its
dripping time. At the end of the dripping time the normal regulation will restart. The other controllers follow the
same logic.
9.2
RANDOM DEFROST
A random defrost mode can be enabled by par.
Syd=rnd
. After any defrost request (received by RTC or timed
by par.
idF
) a random delay will be added. At the end of the added delay the defrost will start. The random
function lead to desynchronize the start of the defrost phases in those cases where more than a cabinet is
installed in the same “island”. The maximum defrost delay is linked to the following parameters:
-
Mdf
=maximum time for any defrost
-
ndE
=delay multiplier
by the following formula:
MAX_DEFROST_DELAY =
Mdf*ndE
(min)
For example: if
ndE=10
and
Mdf=20 min
, the total interval to complete the defrost phase will be 200 min
(worst case).
NOTE:
-
take care about the interval of time available for defrost. It must be used for selecting both
MdF
and
ndE
values
the higher is the
ndE
value and the better is the result in terms of desynchronization. On the other side, the
longer will be the total interval of time required to complete defrosts
10
DIGITAL OUTPUT CONFIGURATION
Depending on the model, one or more digital outputs (relays) can be configurated with one of the following
functionalities.
10.1
CONFIGURABLE OUTPUT
10.1.1
LIGHT OUTPUT
With
oAx=LiG
the relay operates as light output.
10.1.2
DIGITAL OUTPUT ACTIVATION
The auxiliary output can be managed by
digital inputs
(oAx=AUS, i1F or i2F=AUS):
with
oAx=AUS
and
i1F, i2F=AUS
the output is switched on and off following the linked digital input status.
10.1.3
AUXILIARY THERMOSTAT
The auxiliary regulator can be used to manage the auxiliary output. Here follow the involved
parameters:
•
ACH:
kind of regulation for the auxiliary relay:
Ht
= heating;
CL
=
cooling
•
SAA:
set point for auxiliary relay
•
SHY:
differential for auxiliary relay
•
ArP:
probe for auxiliary relay
•
Sdd:
auxiliary output off during defrost
10.1.4
TIMED ACTIVATION
The following parameters can be used to define fixed activation and deactivation intervals.
•
btA:
base time for auxiliary output activation and deactivation intervals
•
Ato:
auxiliary activation interval
•
AtF:
auxiliary deactivation interval
10.1.5
GENERAL NOTES
if
oAx=AUS
and
ArP=nP
(no probe for auxiliary digital output) the AUX output can be managed:
•
by digital input if
i1F=AUS
or
i2F=AUS
•
by auxiliary button (if set as
AUS
)
•
by serial command (Modbus protocol)
•
by fixed interval of time if
Ato>0
and
AtF>0
(if
Ato=0
or
AtF=0
the auxiliary output is disabled)
10.2
ON/OFF OUTPUT (OAX = ONF)
When
oAx=onF
, the output is activated when the controller is turned on and de-activated when the
controller is turned off.
10.3
DEAD BAND REGULATION
With
oAx=db
the output can be used to control, for example, a heater element. It is used to implement
a dead band regulation. If so:
•
oAx=db
cut in is
SET-HY
•
oA1=db
cut out is
SET
10.4
ALARM OUTPUT
With
oAx=ALr
the output operates as alarm output. It is activated every time an alarm happens. Its
status depends on the
tbA
parameter: if
tbA=Y
, the output is deactivated by pressing any key.
If
tbA=n
, the alarm output stays on until the alarm condition recovers.
10.5
ACTIVATION DURING ENERGY SAVING CYCLES
With
oAx=HES,
the output is activated when the energy saving cycle begins.
11
FRONT PANEL COMMANDS
Press to display target set point and the real set point. When in programming mode,
it selects a parameter or confirms an operation
(
AUX/DEF
) Programmable button, see par.
LGC
and
LG2
(
UP
) In programming mode it browses the parameter codes or increases the
displayed value. Other functions related to par.
UPC
and
UP2
(if available)
(
DOWN
) In programming mode it browses the parameter codes or decreases the
displayed value. Other functions related to the par.
dnC
and
dn2
(if available)
(
ONOFF
) Keep it pressed for 3 sec to switch on and off the device
KEYS COMBINATION
+
To lock or unlock the keyboard
+
To enter in programming mode
+
To return to room temperature display
ICON
MODE
MEANING
On
Compressor enabled
Flashing
Anti-short cycle delay enabled (
AC
parameter)
On
Light output enabled
On
Ventilator output enabled
Flashing
Ventilator delay after defrost
,
On
Measurement unit
Flashing
Programming mode
On
Energy saving mode active
On
An alarm condition is present
Flashing
Start-up operations are pending
On
Auxiliary output is activated
On
Bluetooth connection enabled
11.1
SET POINT MENU
The
SET
key gives access to a quick menu where it is possible to see:
•
the set point value
•
the real set point value (
rSE
)
Push and release the
SET
key five times or wait for 60 sec to return to normal visualization.
11.2
CHANGE THE SETPOINT
1.
Push the
SET
key for more than 3 sec to change the Set point value;
2.
The value of the set point will be displayed and the “°C” LED starts
blinking;
3.
To change the Set value, push the
UP
or
DOWN
button.
4.
To memorise the new set point value, push the
SET
button again or wait for 60 sec.
