Beretta POWER PLUS Installation Instruction page 52

Managing the heating demand in the high temperature circuit by analogue input (Par. 14=2 or 3)
The room thermostat in the high temperature circuit is ignored for the heating demand, and the input signal is used to
calculate the output or the system set point.
There is just one analogue input (see terminals 13-14 on the wiring diagram on page 34) on the Master board and this
can also be used for the low temperature circuit (Par.22). The analogue input cannot be used for both the circuits.
ANALOGUE INPUT FOR HEAT OUTPUT, PAR. 14=2 (PAR. 22=2 FOR LOW TEMPERATURE CIRCUITS)
The demand for the high temperature (low temperature) circuit is made according to the following rules:
0-2Vdc: No demand from the high temperature (low tem-
perature) circuit
2-9Vdc: 2-9Vdc: the demand for heat is converted into
an output demand for each Slave. An input of 2V
corresponds to minimum output, 9V to maximum
output (Par.15). Between 2V and 9V the output is
calculated linearly. The hysteresis for the end of
the demand is 0.2V and therefore the demand is
active above 2V and ends below 1.8V.
The burner starts when:
Outlet Temp. ≤ Setpoint_Ch_high (Par.1) – Ch_
high_mod_hist_on (Par.19)
(Outlet Temp. ≤ Setpoint_Ch_low (Par.3) – Ch_
low_mod_hist_on (Par.26))
The burner stops when:
Outlet Temp. > Setpoint_Ch_high (Par.1) +
Ch_high_hist_off (Par.20)
52
(Outlet Temp. > Setpoint_Ch_low (Par.3) + Ch_
low_hist_off (Par.27))
ANALOGUE INPUT FOR TEMPERATURE, PAR. 14=3 (PAR. 22=3 FOR LOW TEMPERATURE CIRCUITS)
The demand for the high temperature (low temperature) circuit is made according to the following rules:
0-2Vdc: No demand from the high temperature (low tem-
perature) circuit
2-9Vdc: the demand for heat is converted into an output
requirement for each Slave, by the PID_CH_high
(PID_CH_low) algorithm. 2V corresponds to a set
point of T_Ch_high_foot, Par. 18 (T_Ch_low_foot,
Par. 24), 9V to a set point of Setpoint_Ch_high,
Par.1 (Setpoint_Ch_low, Par.3). Between 2V and
9V the set point is calculated linearly. The hyste-
resis for the end of the demand is 0.2V and the-
refore the demand is active above 2V and ends
below 1.8V.
The burner starts when:
Outlet Temp. ≤ Setpoint_ch_high (Par. 1) – Ch_
high_hist_on (Par 19)
(Outlet Temp. ≤ Setpoint_ch_low (Par. 3) – Ch_
low_mod_hist_on (Par.26))
The burner stops when:
Outlet Temp. > Setpoint_ch_high (Par. 1) +
Ch_high_hist_off (Par. 20)
(Outlet Temp. > Setpoint_ch_low (Par. 3) +
Ch_low_hist_off (Par. 27)).
250
200
150
100
50
0 1 2 3 4 5
Voltage (Volt)
90
80
70
60
50
40
30
20
10
0 1 2 3 4 5
Voltage (Volt)
6 7 8 9 10
6 7 8 9 10