EVCO S.p.A.
c-pro 3 OEM HRV | Application handbook ver. 4.0 | Code 144CP3OHE404
page 108 of 138
8.4
3-point control of water coils
In addition to modulating and on-off regulation, a 3-point control can also be set using two digital opening control outputs and the closing of the water valve. To enable
this control, both opening and closing relays of the relevant coil must be configured.
To correctly control the water valve, it is necessary to set the following parameters:
-
time taken by the valve to switch from 0% to 100% (parameters
Pb44
for the first coil,
Pb46
for the second coil,
Pb48
for the pre-heating coil,
Pb51
for the
re-heating coil).
-
maximum time to maintain the end-of-run signal on the relays (parameters
Pb45
for the first coil,
Pb47
for the second coil,
Pb49
for the pre-heating coil,
Pb52
for the re-heating coil).
-
minimum variation: if greater than 0, the command to the relays is given only when the actual variation on the control ramp exceeds the set value. This
parameter is the same for all 4 coils (parameter
Pb50
).
Every time the controller is switched on or the power is reset after a black-out, the valve is realigned; for the entire run time (plus any time the signal is maintained for
the end of the run), the valve is closed and the control is interrupted. Once the run time has elapsed, the control will return to its normal operating state. This is neces-
sary to ensure that the valve is correctly positioned.
In the pages related to the coil status, the current state of the water valve will be displayed which can be one of the following, the equivalent displays for c-pro 3 OEM
HRV and EVJ LCD and EPJ LCD is shown in brackets:
1.
Disabled:
the valve is disabled. While in this state you will see the symbol “---” on the user interface.
2.
Closed:
the valve is closed (value 0.0%). In this state, you will see “Closed” (CLOS) displayed on the user interface.
3.
Opening:
the valve is opening. In this state, you will see “Opening” (OPnG) displayed on the user interface.
4.
Open:
the valve is fixed and open at a specific value. In this state, you will see “Open” (OPEn) displayed on the user interface.
5.
Closing:
the valve is closing. In this state, you will see “Closing” (CLnG) displayed on the user interface.
6.
Alignment:
the valve is aligned due to start-up or when power is restored. In this state, you will see “Allin.” (ALIn) displayed on the user interface.
8.5
Second coil
The second coil is always a heating coil and it can be water or electric.
There are 3 types of control that can be configured for the water coil:
- modulating by configuring an analogue output as "Vmix second coil”
- with 3 points by configuring 2 digital outputs, one as “coil 2 opening” and one as “coil 2 closing”. For the information on how it works, please refer to the previous
section.
- on-off by configuring a digital output as “On-Off coil 2”.
If the coil is electric, please refer to the specific sections (8.10.1 and successive)
If the first coil functions in heating mode, the second will be used to integrate the heat, in which case regulation is according to the settings for parameters
PB21
(neu-
tral zone) and
PB22
(differential). The second coil will never be active unless the first coil is regulating to 100% of its capacity.
If the first coil is working in cooling mode and there is no dedicated coil for re-heating, the second coil will act as a re-heating coil in the dehumidification phase to
compensate for any excessive drop in temperature.
In this case, the second coil controls based on the primary control parameters
PB01
(differential) and
PB03
(neutral zone).
If the machine is working in cooling mode and the second coil is a heater coil, the mid-season function will be active, that being a heating phase using heaters if the
temperature falls below the regulation setpoint, in which case parameters
PB23
(neutral zone) and
PB24
(differential) will have effect.
