AERMEC WMT21 Manuel D'installation page 55

When an integral time different from zero is set the resulting regulation is
made of a Proportional plus an Integral action (P + I type).
The smaller the integral time, the greater the influence of the integral action
and vice-versa: with a greater integral time the resulting integral action is
softer. A too soft or null integral action could result in the impossibility
to reach the setpoint temperature, meanwhile a too strong integral
action could possibly generate oscillations in the room temperature. It is
necessary to adjust these parameters according to the actual environment
in which the regulator is installed to get the best regulation accuracy.
The proportional control of the valves can only take place when they are
controlled by the 0..10V outputs. Proportional control cannot take place if
using ON/OFF valves, they will be driven either always ON or always OFF
with hysteresis set on parameter P19.
The fan will be proportional driven only when it is set in automatic speed
(AUTO). The fan speed will be proportional regulated (P + I) even when the
fan motor is a three speeds one.
The distance between the three speed stages is calculated dividing
by three the proportional band and rounding down. For example if the
proportional band is 2°C, the distance between stages will be 0.6°C.
INSTALLER CONFIGURATION
Installer configuration defines the thermostat operation and allows to
adapt it to the different types of plants and systems. To access the
configuration menu, simultaneously press the " " e "" buttons for a
few seconds until "COn" (configuration) appears on the display.
Once entered in configuration menu, pressing " " scrolls through the
various parameters, identified with P and the parameter number, from
P01 to P25. The configuration end is displayed with "End". Press " "
again to save the configuration and and return to normal operation.
Press the " " button, at any time, to exit from the configuration menu
without saving the changes.
When scrolling the parameters pressing button " " or "" or ""
displays its current value.
To change the value, when it is displayed, press button "" or "".
To prevent unauthorised access to the configuration remove the internal
jumper (JP5) shown in Fig. 6. Any attempt to access the configuration
will display the flashing " " icon.
The installer configuration consists of two lists of parameters:
- main parameters P01 to P25 (table 1)
- extended parameters C01 to C23 (table 2)
The extended parameters C01-C23 allow an advanced thermostat
configuration.
When the display shows "COn" at configuration start or "End" at
configuration end, press the " " button to access the extended
parameters.
INSTALLER CONFIGURATION RESET
In order to reset the installer configuration, so that all parameters are reset
to the factory default values, enter the configuration mode by holding
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