AERMEC VMF-E19 Manual Del Usuario página 27

VALVE ON/OFF FUNCTION
If a shut-off valve is installed (dip1 ON), the position of the probe can be managed both upstream and downstream of the valve
itself (on the standard position available in the heat exchanger). The difference between the two options lies in how ventilation is
managed. If the water probe is upstream of the valve (dip2 ON) or isn't installed, there is an exchanger pre-heating function that
enables the fan 2'40'' after the first opening of the valve.
For this exchanger pre-heating function, the valve in question is Y1 in the case of a 2-pipe system (dip5 Off) or Y2 with a 4-pipe
system (dip5 On). The fan inhibition time is then calculated automatically according to how long the valve has remained closed; in
this way, it can vary from a minimum of 0' 00'' to a maximum of 2' 40''. This ventilation enabling delay in relation to the opening of
the valve is reset if the electric heater is enabled, the purpose being to guarantee greater safety for the user.
The figure below indicates the valve operating logic if the thermostat is used with thermostat-controlled ventilation logic or modulated
logic. As you can see, in HEATING mode the valve is used by exploiting the capacity of the terminal to dispense heat even when
ventilation is disabled (stack effect). On the one hand, this takes advantage of the stack effect, and on the other it avoids the
continuous opening and closing of the valve (that takes a few minutes to respond), which means the water in the terminal is always
circulating during normal operation.
In COOLING mode, thermostat control of the valve is not synchronised with that of the fan. This helps take full advantage of the cooling
capacity of the machine, and ensures more precise room temperature control.
If the thermostat uses continuous ventilation, the valve operating logic is as shown below:
MODULATING VALVE OPERATION
For hydronic systems requiring a variable flow rate in the secondary circuit, the VMF thermostats can manage modulating valves thanks
to the VMF-MOD expansion.
230V AC input for VMF-FCL
board
Outputs for valve control
Vou1
GND
Heating setting
Valve
Heating setting
Valve
Vou2
+24[V]
GND
Cooling setting
Dead band
Cooling setting
Valve
Dead band
AVMFE19LJ 2011 - 5779300_05
Valve
Dip switches for selecting the
modulating valve activation curves
Humidity probe input
VMF-MOD expansion
VMF-E19 thermostat
27