EVCO S.p.A.
EV3 MVC & EVD MVC
| Application manual ver. 2.2c | Code 1443DMVCI224
page 56 of 74
If parameter C48 is set to 0 temperature regulation takes priority over dehumidifying; in this situation if the regulation temperature
falls below the setpoint - band/2 the dehumidifier request is inhibited. This parameter can be used to limit excessive cooling caused by
dehumidification, for example if a post-heating coil is not present.
10.10.3
Humidification
If the winter cycle is activated the relative humidity in the room is likely to be quite low. To guarantee comfort in these conditions too,
the regulator is able to manage an ON-OFF humidifier, which is activated if the humidity percentage falls below the setpoint - band
(C46 - C47), provided that a
Humidifier
digital output is configured and the
Humidity probe
is configured and not in alarm mode. The
humidifier is switched off when the humidity rises above the setpoint C46.
If the
Supply probe
is also configured, the humidifier is switched off to avoid condensation, if the supply temperature falls below the
C49 limit.
10.11
External air limitation
This regulation is active only if the
Supply probe
has been configured and the function is enabled (C60).
In both summer and winter cycles, if the external temperature is particularly extreme (very high in summer and very low in winter) it is
possible for the regulation setpoint not to be reached even with the heating or cooling resources at their maximum power.
In this situation external air limitation comes into play and, by reducing the quantity of external air, it limits this problem.
This function helps to maintain the room temperature even in very difficult environmental conditions.
When the regulation temperature is outside the neutral zone with heating/cooling resources at 100%, the external air limitation
function first closes the mixing chamber damper down to its minimum aperture (C07) and then reduces the fan speed down to the
minimum speed (C06) using regulation in the incremental neutral zone with the usual parameters for the temperature regulation
(C39/C40) in progress (heating or cooling).
If the temperature reaches the regulation setpoint, the regulation “is reversed” by first gradually resetting the fan speed to normal and
then opening the damper to its normal aperture.
N.B.: this function will make use of whatever resources are installed on the machine. For example, for units without dampers, the
heating/cooling power will first be maximized (depending on the active function) and then the fan speed will be reduced; for units
without dampers or treatment coils, the speed of the fans will be controlled directly.
11
INTERNAL STATUS
Status table
specific values for the temperature probes:
3276.4: Disabled
-3276.8: Error
specific values for the pressure probes:
327.64: Disabled
-327.68: Error
Specific analogue output values
- 1: Disabled
Digital input and output values
- 1: Disabled
0: OFF
1: ON
Label
Visibility default
min
max
UM
description
Status
Status
S01
U
0
1
Unit status
0: ON
1: Stand-by
2: Stand-by from time band
3: Stand-by from DI
S02
U
Time bands
0: OFF
1: ON
