AERMEC VMF-E1X Manuel D'utilisation Et D'installation page 15

The unit can begin ventilation some time
after start-up - usually up to 2'40" (pre-
heating function).
The delay is zero-set in units with an
electric heater.
• Anti-freeze protection
Controls on OFF position. The fan coil
can restart in heating mode (set point
12°C) if the ambient temperature falls
below 7°C and the temperature of the
water in the system is suitable.
In the fan coil networks, the Slave
fan coils can activate the anti-freeze
protection regardless of the settings on
the Master fan coil.
If the anti-freeze protection is active on the
Master fan coil, all the other Slave fan
coils will also adopt a set point of 12°C,
regardless of their ambient conditions.
• Ambient temperature probe
If the ambient temperature probe on the
Slave fan coils is faulty, the temperature
will be measured by the probe of the
Master.
• Ambient probe correction
To obtain a better ambient temperature
adjustment, the thermostat applies
special algorithms to correct the
ambient probe installed on the fan coil;
the probe is in contact with the housing,
and is therefore influenced by it.
The dynamic correction is a correction
algorithm of the ambient probe which
takes into account the particular
operation status of the fan coil in any
one moment. More precisely, there
are two possible cases of dynamic
correction:
- Dynamic correction A: in the case
of systems without a valve (or with a
downstream probe), the correction
depends on the water and ambient
temperatures.
- Dynamic correction B: in the case of
systems with a valve and an upstream
probe, the correction depends on the
Valve and on the Water and Ambient
temperatures. Unlike the previous
correction, this one uses different time
constants to calculate the appropriate
correction (because the housing is
influenced in a different way).
• Water probe
There is a water temperature probe in the
heat exchanger of the unit.
The Slave fan coil can work without the
water probe: if it is absent or faulty,
the temperature will be measured by
the Master probe alone. In this case,
ventilation is always enabled on the
Slave fan coil.
The water temperature probe can be
positioned downstream or upstream
from the shutoff valve, so also the dip-
switches on the board must be set. The
difference lies in the management of the
ventilation of the fan coils with valve.
Setting the dip-switch as a downstream
probe of the valve, ventilation start-
up (changeover) is dependent on the
temperature of the air in the room.
Setting the dip-switch as an upstream
probe of the valve, ventilation start-up
is dependent on the temperature of the
water in the system. With this setting,
the pre-heating function is activated,
and there is a ventilation start-up delay
of between 0" and 2'40".
To position the bulb on the delivery pipe
upstream of the valve, the standard
water probe must be replaced with the
VMF-SW probe accessory.
•Ventilation
3-speed ventilation can be controlled
both manually and automatically.
- Manual, with the selector in position
V1, V2 and V3. The fan is used with
on-off cycles at the selected speed.
- Automatic, with the selector on
AUTO. The fan speed is managed by
the thermostat, on the basis of the
ambient conditions and the fan coil
configuration.
Thermostat settings:
- 3-level thermostat, With the selector
on AUTO. The fan maintains the
speed relating to one of the three
predetermined steps, depending
on the difference between ambient
temperature and set point. Once it
has reached the set point, the fan will
switch off.
• Ventilation management
Ventilation settings:
- Continuous ventilation. Ventilation
is always active. The temperature is
controlled by intercepting the flow
of water to the fan coil. This function
requires the presence of a water valve
(accessory), and cannot be activated
simultaneously with the "modulated
output thermostat" option.
- Thermostat-controlled ventilation.
Ventilation switches off when the set
temperature is reached (set point).
• Valve adjustment logics
With the Thermostat-controlled
ventilation setting, the valve is managed
with the following logics:
- Heating - the valve is managed to
exploit the stack effect of the fan coil,
and to provide heat even with the fan
switched off. These settings also reduce
the number of valve openings and
closings; with hot water circulating
in the fan coil, a request from the
thermostat will produce ventilation
immediately.
- Cooling - to make the best use of the
unit's cooling capacity and perform a
more accurate check on the ambient
temperature, the valve opening does
not coincide with ventilation.
• External contact
The board offers the possibility of a
connection with an external contact.
With a closed external contact, the unit
is configured as in the thermostat OFF
position (except when the thermostat
is in the Anti-freeze Protection position
or when the ambient probe is absent
or faulty). This contact can be used
to manage inputs such as a remote
ON-OFF controlled, a presence sensor,
a window contact, a faulty circulation
pump signal, etc.
In fan coil networks, only the external
contact of the Master fan coil is
enabled. If the master input is closed,
all the slave fan coils of the network are
switched off.
• Microswitch contact
The board offers the possibility of a
connection with the Microswitch
contact located on the delivery fins.
With the fins closed, the fan coil is
100% OFF.
In fan coil networks, when the fin of the
Master fan coil is closed, ventilation
stops but the electronic thermostat
board and the other fan coils in the
network carry on working.
• "Sleep" energy saving function
Presence sensor to enable the "Sleep"
function from an external contact
(SP). The Sleep energy saving function
involves varying the ambient set-point
by 2 or 5 degrees (depending on the
settings) when there are no people in
the room.
In heating mode, the set point temperature
is lowered.
In cooling mode, the set point temperature
is raised.
To activate the Sleep function for energy
savings, you must connect a presence
sensor (with NO logic) to the SP
contact.
The function is not active in Anti-freeze
protection mode, or if the ambient
probe is faulty.
In fan coil networks, only the presence
sensor contact of the Master fan coil
is enabled. The setting of the Master
is sent to all the Slave fan coils in the
network.
• Emergency operation
In the event of a faulty ambient probe,
the electronic board can automatically
detect the problem and enable an
emergency program to avoid any
inconvenience for the user, who is
immediately informed of the fault (LED
indicator lights).
• Behaviour with a faulty water
temperature probe
Ventilation is always active.
The season change is made on the basis of
the difference between the setting made
and the actual ambient temperature.
If the actual ambient temperature exceeds
the Heating set point by a value equal
to the dead band, there is an automatic
swap to Cooling operation.
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