AERMEC WMT21 Manual De Instrucciones página 56

down the keys " " and "" until the display shows "Con", then hold
down the two keys "" and "" for a few seconds, until the display
returns to the usual screen.
DESCRIPTION OF MAIN CONFIGURATION PARAMETERS
The main installer configuration parameters are shown in table 1 and
explained below.
P01: System type selection.
2 pipes system: when configured for a two-pipes system the controller
drives only one valve, wired at the "heating" valve terminal, both when
heating and when cooling, as the same valve is going to control either hot
or cool water flow.
See wiring diagram in Fig. 12a and Fig. 12b.
In case of a two-pipes system without valve, and therefore with no wirings
at the valve output terminal, make sure to set parameters P03 and P04 to
"fan control" in order to get an effective regulation.
4 pipes system: when configured for a four-pipes system the controller
drives both valves outputs in order to activate either the hot water or
the cooling one according to the actual requirements of the controlled
environment.
See wiring diagram in Fig. 12c and Fig. 12d.
Electric heater system: the regulator is configured to control a system
equipped with an electric heater: see the section "Electric heater system"
for more details.
Integrating electric heater system: the regulator is configured to control
a system equipped with an electric heater: see the section "Integrating
electric heater system" for more details.
P02: This parameter sets the way how the controller switches from the
cooling mode (summer) to the heating mode (winter) and vice versa.
The switching can be either manual or automatic:
Manual: The user manually sets the heating or the cooling mode.
Automatic: The controller automatically switches from the heating to the
cooling mode or vice-versa.
This automatic operation is different according to the system type as set
with parameter P01.
In case of a 4-pipes system or an "electric heater" system, the thermostat
operates with a neutral zone. Therefore it activates heating or cooling
according to the set point temperature.
In case of a 2-pipes system or an "integrating electric heater" system,
the controller operates a changeover according to the delivery water
temperature.
When the delivery water temperature is low (that is below the threshold
set with parameter C01) the controller switches to cooling mode.
On the opposite side, when this temperature is high (that is above the
threshold set with parameter C02) the controller switches to heating
mode. In case the supply temperature is neither too low nor too high the
operating mode is kept unchanged, and can be manually changed.
When the delivery water sensor is not installed or it is not properly
working, no automatic selection is performed and only the manual
switching is allowed.
Remote selection: In a building with several regulators all inputs can be
wired together for a remote selection coming from the central heating
room. On C17, C18 and C19 parameters it is possible to choose the input
and the mode (normal or reversed) to be associated to the "remote heating/
cooling" selection.
In the wiring diagrams it is shown a wiring example for a remote heating/
cooling selection.
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