AERMEC WMT21 Manuel D'installation page 57

P03 and P04: these parameters set which outputs are controlled.
When in heating mode parameter P03 is used, when in cooling mode P04 is
used instead. Each parameter sets whether temperature is to be regulated
through valves, fan, or both. When valves only is chosen, the fan will be
turned on even after temperature has reached the setpoint; when fan only
is chosen the valve will be powered even after temperature has reached
the setpoint.
In systems with an electric heater, these parameters cannot inhibit the
valve outputs because these outputs are driven according to the specific
system type.
P05: This parameter tells the thermostat which kind of fan motor need to
be driven: an EC motor on the 0-10V proportional output or a three-speeds
fan motor on the three relay outputs.
Also it is possible to select a "reverse action" for the proportional fan
output, like the valve outputs, it will give a 0V to turn on the motor at top
speed and 10V to turn it off.
P06 and P07: These parameters tell the thermostat which kind of valve
will be wired to the heating output and the cooling output, respectively.
The thermostat can be configured to control NO or NC (normally open or
normally closed) ON/OFF valves or 0..10V proportional valves.
In case of 0..10V proportional valve the following kind of action can be
configured:
Direct action: means that the thermostat provides 0V at the output to
close the valve and 10V to open it.
Reverse action: means that the thermostat provides 10V at the output to
close the valve and 0V to open it.
P08: This parameter sets the type of the sensor used for the acquisition of
the delivery water temperature.
When set to value 0 or 1 we mean that a sensor is used for the acquisition
of the water temperature, properly wired to terminals 13 and 14: when
1 is set, the temperature value can also be displayed, according to the
user choice. In case 0 is set, the information coming from the temperature
sensor is still used for the regulation purpose, even if its value can not
be displayed.
When set to value 2 we mean that a bimetallic thermostat will be
connected to terminals 13 and 14 to perform only the cut-off temperature
function when in heating mode.
P09: This parameter enables the room "de-stratification" function. With
this function the fan is turned on, at its lowest speed, for about 1.5
minutes every 15 minutes.
The function is only active when the fan should be turned off according to
the room temperature regulation.
P10: In case of a black-out the thermostat remembers its latest state
and when the power returns, it restarts with the same settings (on/off,
heating/cooling, etc.). Anyway, in some situations it is requested that the
thermostat restarts to a know state (i.e. always OFF or always ON). This
can be accomplished by setting parameter P10 to "2" (always restart from
"ON ") or "3" (always restart from "OFF").
P11: Room temperature sensor selection.
This parameter sets whether the temperature sensor used for regulation
has to be the internal one in the thermostat or the external one (optional).
P12: With this parameter a slight correction (offset) for the acquired room
temperature can be set. Actually it could happen that in some installations,
due to the sensor location (either internal or external) the temperature
readout is not accurate.
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