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IDJULJ 1207 - 6339500_00
12°C, independent from their ambient
conditions.
During the anti-freeze protection opera-
tion the fan coil units are always forced
to work in heating mode.
In the case that the water temperature
sensor is absent or if continuous venti-
lation, the fan is always enabled.
In the case that the valve is present with
water sensor mounted upstream, the
pre-heating of the heat exchanger is
still carried out.
• Ambient temperature sensor
The ambient temperature sensor is not
required on the slave because they can
use the sensor on the master, although
the ambient temperature sensor can be
used on the slave to avoid the creation
of a micro-climate.
If the ambient temperature sensor on the
slave fan coil unit is faulty then in its
absence the temperature read by the
master sensor is used.
If the ambient temperature sensor on the
master fan coil unit is faulty then the
slave fan coil units not fitted with sen-
sor will operate in emergency mode,
whilst the fan coil units fitted with
ambient temperature sensor will con-
tinue to operate normally.
• Water temperature sensor
The unit is equipped with a water tem-
perature sensor in the heat exchanger.
The fan coil unit can operate without
water sensor, and if absent (or faulty)
the ventilation is always enabled.
-
Installation in TTL network
The slave fan coil unit can operate
without water sensor, and if absent
(or faulty) the temperature reading is
taken from the sensor on the master, in
which case the slave fan coil unit ven-
tilation is always enabled.
-
Installation with valve
To position the bulb of the water tem-
perature sensor on the outlet tube
upstream
of the valve, the standard
water sensor must be substituted with
the accessory sensor VMF-SW.
The water temperature sensor can be
positioned
downstream
or
upstream
of the control valve, and as a conse-
quence the dip-switch on the board
must be set. The difference consists in
the control of ventilation of the fan coil
units with valve.
Setting the dip-switch as
sensor down-
stream
of the valve the ventilation is
started based on the ambient air tem-
perature.
Setting the dip-switch as
sensor
upstream
of the valve the ventilation is
started based on the water temperature
of the system. This setting activates the
pre-heating function and delayed start-
ing of the ventilation, variable between
0” and 2’40”.
• Ambient sensor correction
To obtain the best ambient temperature
control the thermostat applies correc-
tive algorithms of the ambient sensor
mounted on the fan coil unit, which is
influenced by being mounted in con-
tact with the casing.
The dynamic correction is a corrective
algorithm of the ambient sensor which
takes into account the operating status
of the fan coil unit. There are two pos-
sible dynamic corrections available:
-
Dynamic Correction B:
for systems
w i t h o u t va l ve ( o r w i t h s e n s o r
d o w n s t r e a m ) t h e c o r r e c t i o n
depends on the water and ambient
temperatures.
-
Dynamic Correction A:
for systems
with valve and sensor upstream the
correction depends on the valve and
the water and ambient temperatures.
Wi t h r e s p e c t t o t h e p r e v i o u s
correction, this uses different time
constants in calculating the correction
to be applied (because the casing is
affected differently).
• Ventilation
The three speed ventilation can be con-
trolled both manually and automati-
cally.
-
Manual,
selecting the speed V1, V2
and V3. The fan is cycled on-off at the
selected velocity.
-
Automatic,
with selector in AUTO
position. The speed of the fan is con-
trolled as a function of the ambient
conditions and the configuration of the
fan coil unit.
Thermostat settings:
-
3 level thermostat.
AUTO selection. The ventilation speed
is maintained between the 3 prede-
termined settings as a function of the
difference between the ambient tem-
perature and the set point. Once the
set point is reached the ventilation is
switched off.
-
Modulating capacity thermostat.
AUTO selection. The ventilation car-
ries out alternating velocity cycles as
a function of the difference between
the ambient temperature and set point.
Once the set point is reached the ven-
tilation is switched off. This setting is
not compatible with continuous venti-
lation control.
• Ventilation Control
Ventilation settings:
-
Continuous ventilation.
The ventilation
is always enabled. Temperature control
is through interruption of the water
flow to the fan coil unit.
WARNING: This function requires
the water valve (accessory) and can-
not be activated at the same time as
the Modulating capacity thermostat
option.
-
Thermostatic ventilation.
The ventila-
tion is switched off on reaching the set
temperature (set point).
• Valve control logic
With the settings
Thermostatic ventila-
tion
or
Modulating capacity thermo-
stat
the valve is controlled with the
following logic:
-
Heating
, the valve is controlled to
exploit the stack effect of the fan coil
unit and distribute heat even with the
ventilation switched off. These settings
reduce the number of valve openings
and closings, circulating hot water in
the fan coil unit, and at the demand of
the thermostat, ventilation is immedi-
ate.
-
Cooling
, to best exploit the cooling
capacity of the unit and effect more
accurate control of the ambient tem-
perature, the opening of the valve is
phase-shifted with respect to the ven-
tilation.
• External contact
An external contact is available on the
board to connect to. With the external
contact closed the unit is configured as
in the OFF position of the thermostat
(except in the case of the thermostat
being in Anti-freeze protection or that
the ambient thermostat is absent or
faulty). This contact can be used to as
an input from a remote ON-OFF sig-
nal, occupancy sensor, window con-
tact, circulating pump failure signal,
etc.
In networked fan coil units only the
external contact of the master is ena-
bled. When the input to the master is
closed all the slave fan coil units on
the network are switched off.
• Emergency function
In the case of an ambient sensor failure
the electronic board is capable of
automatically detecting it and adopt
and emergency function, in order to
avoid discomfort to the user whilst
signalling the fault (illumination of the
LED).
- Operation with water temperature
sensor failure
The ventilation is always enabled.
The enabling of operating mode is as a
function of the difference between the
set temperature and the ambient tem-
perature.
If the ambient temperature exceeds an
interval equal to the dead band set in
heating then it goes to cooling mode.
If the ambient temperature drops an
interval equal to the dead band set in
cooling then it goes to heating mode.
- Operation with ambient temperature
sensor failure
Selector in OFF/Aux position:
- ventilation is switched off
- valve is closed
Selector in AUTO, V1, V2, V3 position:
- valve is always open
- ventilation carries out On/Off cycles
of variable durations as a function
of temperature setting position. The
maximum duration of the cycle is
5'20".
