38
The setpoint followed by the central heating delivery probe will be calculated using the
following formula:
T
ch
[°C] = [( T
room
[°C] – T
ext
[°C]) * dc/10 ] + T
room
[°C]
T
ch
: central heating setpoint calculated by the system
T
room
: room temperature set by the user
T
ext
: external temperature measured by the probe
dc: dispersion coefficient of the building, set using the parameter
idx:
002
.
Examples of curves with T
room
set to 20°C and JP7 = 0
Examples of curves with T
room
set to 20°C and JP7 = 1
HEATING REQUEST
When the room thermostat (TA) contact is closed, or following a request by the weekly
program, if the board is in winter mode the system pump is activated only if the primary
exchanger temperature is higher than the temperature set using parameter
idx:
006
. If
the temperature value detected by the primary exchanger probe is lower than the delivery
setpoint, the triacs are switched on in sequence based on the required power. This only
happens after a time that can be set using the parameter
idx:
005
, to allow, for
example, the opening of any zone valves. The instantaneous power of the boiler and the
control of the G1÷G4 triacs is through the PID regulator. If the request of the internal
sanitary water storage tank with probe (
JP8
= 0 and
P8
= 0) is activated at the same time,
only commands G1, G2 and G3 are activated, to avoid exceeding the nominal boiler
output (6, 12 or 18 kW). At the end of the request the circulator remains powered for a time
equal to the value set using the parameter
idx:
004
.
INTERNAL STORAGE TANK REQUEST (JP9 = 0 and P8 = 0)
Stand-by or with simultaneous heating request:
In this case, if the temperature detected by the storage tank probe (SB) is below the
storage tank setpoint -1°C, the G5 command for the storage tank heater is activated.
When the temperature detected by the storage tank probe is higher than the storage tank
setpoint, the G5 command is deactivated. The activation of G5 causes G4 (2 kW) to switch
off, so that the maximum total consumption of the system is always 6, 12 or 18 kW
(depending on the model).
20
25
30
35
40
-20
-15
-10
-5
0
5
10
15
20
35 30 25 20
15
10
8
5
Text [°C]
Tch [°C]
28
33
38
43
48
53
58
63
68
73
-20
-15
-10
-5
0
5
10
15
20
35 30
25
20
15
10
8
5
Text [°C]
Tch [°C]
