Additional Functions - AERMEC VMF-E19 Manual Del Usuario

ADDITIONAL FUNCTIONS

ENABLING VENTILATION
The figure indicates the activation thresholds of the ventilation according to the water temperature also shows showing season changeover
(water side) but also the ventilation enabling thresholds in Heating mode (Minimum value check) and Cooling mode (Maximum value check).
Depending on the setting of Dip 4, Normal band (heating enabling at 39°C, cooling enabling at 17°C) or Reduced band (heating enabling at 35°C,
cooling enabling at 22°C) is selected.
The absence of a water probe for 2-pipe systems prevents not only season operating changeovers but also Minimum water temperature checks in
Heating and Maximum water temperature checks in Cooling, so ventilation is always active.
In the case of a 4-pipe system with just one water probe, the probe is only used to check the Minimum ventilation value in Heating mode. If you
also want to check the Maximum value in Cooling mode, a probe must be installed on the cold water coil as well (the VMF-E19 thermostat can
manage two water probes).
AMBIENT PROBE CORRECTION
If the probe is on the user interface, no correction will be made to the temperature value measured. If the probe is on the machine, a correction is
applied:
The possible corrections (on the basis of the operating mode and the type of thermostat configured) as follows:
ANTI-FREEZE PROTECTION
The anti-freeze protection function makes sure the ambient temperature never falls to freezing values (even when the selector is OFF). If the
temperature falls below 7°C, the thermostat works in HEATING with a set value of 12°C and AUTO ventilation (as long as the water temperature
allows it). If there is no water probe, or continuous ventilation is enabled, the fan is always active. If there is a valve and an upstream water
probe, or no water probe, the heat exchanger undergoes a pre-heating cycle in any case. The thermostat quits anti-freeze mode when the
ambient temperature rises above 9°C.
MICROSWITCH LOGIC
The microswitch can have several separate functions depending on the position of Dip 8 (SW1) and Dip 1 (SW2):
DIP 8 OFF (Dip 1 SW2 OFF: fan coils without radiant plate)
The function of the microswitch is to completely disable the fan when it is open (in mechanical terms, this means the closed position of the fin). If
the electric heater is active, there is a post-ventilation cycle when the microswitch is opened (fin closed) to prevent it from overheating. (This is
the only situation where ventilation is enable even with the microswitch open).
DIP 8 ON (Dip 1 SW2 OFF: fan coils without radiant plate)
The function of the microswitch is that of season changeover. This mode is necessary for the FCX/FCZ DualJet fan coils, or in all applications where
you want the season changeover to be activated via an external contact managed by a centralised system.
Dip 8
OFF
OFF
ON
ON
DIP 1 SW2 ON
For fan coils that manage the radiant plate, the function of the microswitch is to disable ventilation.
EXTERNAL CONTACT LOGIC
The use of the thermostat envisages an external contact that, when closed, switches the thermostat OFF (except when the thermostat is in anti-
freeze mode or the ambient probe is faulty). This contact may be useful, for example, for managing inputs such as a window contact, faulty
circulating pump, etc.
SLEEP FUNCTION
The Sleep function on the VMF-E19 thermostat is available if the thermostat is interfaced with a presence sensor (with normally open logic)
connected to its SP input.
In practice, this function varies the fan coil adjustment setting if there is nobody in the room in question (lowering the value if heating mode is
active, or increasing it if cooling mode is active). The purpose is to ensure energy savings. More specifically, if the VMF-E19 thermostat board is
connected to a presence sensor, the SP input logic is as follows:
Corrected probe value = Measured probe value – Correction
Heating
Cooling
Function
External enabling
External enabling
External season changeover
External season changeover
External contact input
Closed
Open
SP input
Dip 7 Off
Open
Closed ∆ = 5°C
Fixed = 0.0°C
Fixed = -1.5°C
Microswitch input Machine status
Closed
Open
Closed Cooling mode
Open Heating mode
Machine status
OFF
ON
Heating
Dip 7 On Dip 7 Off
∆=0 ∆=0 ∆=0
∆ = 2°C ∆ = -5°C
AVMFE19LJ 2011 - 5779300_05
(no correction)
ON
OFF
Cooling
Dip 7 On
∆=0
∆ = -2°C
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