Temperature Regulation - AERMEC WMT21 Manuel D'installation

When the fan motor is proportional driven, for the same purpose of cooling
the heater down, it is possible to set on parameter C14 a minimum speed
that will be maintained when the electric heater is on.
In case the cut-off temperature function is used in this system, the fan will
never be inhibited while in heating mode, since the electrical heater will be
turned on in advance instead.
ECONOMY FUNCTION
The "Economy" function allows to temporary set an energy saving
mode through a reduction of the actual setpoint temperature by a step
(configurable) when in heating mode, or increasing it by the same step
when in cooling mode.
The value for this reduction step is set with parameter P18: when this is
set to 0.0 the Economy function is actually disabled. The Economy mode is
activated by the " " button, as described in the "Description of controls"
section.
The Economy mode can be remotely activated in centralised mode,
even for multiple thermostats, using the inputs to terminals 3 or 4 (see
parameters C17 and C18).
Since the thermostat is sensitive to signal status changes and not to the
level, use the " " button to change the activation status of the Economy
function, even when it is forced by the centralised signal. When the
Economy function is activated (" " icon on), the fan speed is limited to
the first or to the value set on parameter C11 for fans with a proportional
control.
DIRTY FILTER WARNING FUNCTION
Fan-coils and other devices including a fan are often equipped with a
filter for the air in the suction path, which needs a periodical maintenance
and cleaning or replacement. This regulator can warn the user when the
maintenance has to be made, provided the "Dirty filter warning" function
has been enabled.
The function is activated by setting the time-to-maintenance on parameter
P25. The thermostat will count the fan operation time and when the
threshold set in P25 (per 100 hours) is reached, the "
on the display. Once the filter has been cleaned, to reset the warning and
the time counter keep the " " button pressed for 10 seconds, until the "
" filter icon disappears from the display.

TEMPERATURE REGULATION

This device can drive in a proportional way both valves and fan in order
to control room temperature with the highest comfort and energy saving.
Nonetheless each different environment needs a different set for some
parameters in order to get an accurate regulation.
Parameters responsible for the regulation accuracy are:
- Proportional band: C03 and C04
- Integral time: C05 and C06
For each of the settings two parameters are available, because the user
is allowed to set different values for heating and cooling mode. The
proportional band in °C or °F is the difference between the setpoint
value and room temperature that ensures the valve is fully opened by the
regulator and/or turns on the fan at the maximum speed.
The narrower the proportional band, the fastest is the regulator to
counteract temperature variations in the room. Yet a too "narrow" value
for this parameter can result in room temperature oscillations or system
instability.
A too "wide"value could result in the impossibility to reach the setpoint
temperature in the room. When the integral time is set to zero, no integral
action is made and therefore the regulation is purely proportional (P type).
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" filter icon blinks