Setting The Temperature Controller - Beretta POWER PLUS Installation Instruction

Setting the Temperature Controller

1 Attenuation_High
Attenuation function for the HIGH TEMPERATURE circuit (parameter 21)
Two cases are possible:
- Operation with fixed set point, Par. 14=0
- Operation with climate control Par. 14=1.
OPERATION WITH FIXED SET POINT, PAR. 14=0
With attenuation in the high temperature circuit disabled, Par21=0, when the thermostat in the high temperature
circuit closes, the heating demand is signalled. When opening, the system stops.
The Master controller starts the pump in the high temperature circuit PZ1 and the loop pump PZ3, if the parameter
for the third pump is set to 0 (Par. 34=0), otherwise the third pump remains off.
The set point for the high temperature circuit can be set on the Master controller, Setpoint_T_CH_High = Par. 1, pre-
set to 70°C, in the range from 10°C to T_CH_high_limit=Par 17, in turn pre-set to 80°C.
The set point used will be the value set for parameter 1.
The burner is on when:
Manifold Temperature <=Set point – Start hysteresis.
The start hysteresis can be set, CH_High_mod_hyst_on = Par. 19, pre-set to 7°C, between 0 and 20°C.
The Master controller converts the heating demand into an output requirement for each slave controller.
The burners are off when:
Manifold Temperature >=Set point + Stop hysteresis.
The stop hysteresis can be set (CH_High_mod_Hyst_off=Par. 20, pre-set to 3, between 0 and 20°C).
48
When the attenuation in the high temperature circuit parameter is enabled, Par. 21≠0, the contact on the high tem-
perature thermostat is ignored, and a demand for heat in the high temperature circuit is present when:
Manifold Temperature <=Set point – Start hysteresis
The demand for heat stops when:
Manifold Temperature >=Set point + Stop hysteresis.
The set point in this case coincides with the value set for parameter 1 (Setpoint_T_CH_High), if the contact of the
high temperature thermostat is closed, while it is calculated as the value set for parameter 1 minus the attenuation
(Setpoint_T_CH_High-Attenuation_high) if the contact is open.
OPERATION WITH CLIMATE CONTROL, PAR. 14=1
If the attenuation in the high temperature circuit parameter is equal to 0, attenuation_high=Par. 21=0, the behaviour
is the same as in the previous paragraph, except the set point is calculated according to the outside temperature.
If the outside temperature = T out_min=Par. 37, pre-set to 0°C, then set point =setpoint_T_Ch_high
If the outside temperature = T out_max=Par. 38, pre-set to 18°C, then set point = T_CH_high_ foot=Par. 18, preset
to 50°C.
Between the two outside temperature values, the set point is calculated linearly.
Pre-set to 0.