Beretta Power Plus Box 1001 EXT, Installation Manual

Page: 26 / 40

26
3
DHW_Priority
DHW priority (parameter 9)
0 = Shifting priority A
The purpose of shifting priority function A is that the system
can also serve heating if the heating demand is low.
The system responds to the heating demand if:
(Setpoint_Ch - 50°C) < Temp_collettore < (Setpo
1°C)
Setpoint_Ch = Setpoint of the high or low temperature
circuit depending on demand.
1 = Shifting priority B
The purpose of shifting priority function B is that the system
never stops the heating service for too much time.
The system responds to the heating demand if:
(SetpoT_Tank_extra) - 50°C < Temp_collettore <
(Setpoi T_tank_extra) + 1°C
T_tank_extra = Par. 10 = preset to 30°C.
2 = Absolute priority (only DHW service)
Preset to 0.
9 .3 Heat control setting
1
Attenuation_High
HIGH TEMPERATURE circuit attenuation function
(parameter 21)
There are 2 cases:
- Fixed point operation Par. 14=0
- Operation with climatic control Par. 14=1.
FIXED POINT OPERATION, PAR. 14=0
With the high temperature circuit attenuation disabled,
Par21=0 when the high temperature circuit thermostat is
closed, the heating demand is activated. When opened,
the system turns off.
The Master control unit activates the high temperature
circuit pump PZ1 and the system pump PZ2 (if parameter
P34=0).
On the Master control unit it is possible to set the high
temperature circuit setpoint, Setpoint_T_CH_High = Par.
1, preset to 70°C and settable from 10°C to T_CH_high_
limit=Par 17, which is in turn preset to 80°C. The setpoint
used will be the one set with parameter 1.
The burner is on when:
Manifold temperature <=Setpoint – ignition hysteresis.
Ignition hysteresis can be set, CH_High_hyst_on = Par. 19,
preset to 7°C, can be set between 0 and 20°C.
The Master control unit converts the heat demand into
power demand for each slave control unit.
The burners are off when:
Manifold temperature >=Se shut-off hysteresis .
Shut-off hysteresis can be set (CH_High_Hyst_off=Par. 20,
preset to 3, can be set between 0 and 20°C).
With the high temperature circuit attenuation parameter,
Par. 21≠0, the high temperature thermostat contact
is ignored and a heat demand is present for the high
temperature circuit when:
Manifold temperature <=Setpoint – ignition hysteresis
The heat demand stops when:
Manifold temperature >=Se shut-off hysteresis .
The setpoint in this case coincides with the value set for
parameter 1 (Setpoint_t_ch_high) if the high temperature
thermostat contact is closed, whereas it is calculated as the
value set for parameter 1 less the attenuation (Setpoint_t_
ch_high-Attenuation_high) if the contact is open.
OPERATION WITH CLIMATIC CONTROL, PAR. 14=1
If the high temperature circuit attenuation is equal to 0 ,
Attenuation_high=Par. 21=0, its behaviour is the same as
the previous paragraph, with the exception that the setpoint
is calculated based on the outdoor temperature.
If the outdoor temperature = Tout_min=Par. 37, preset to
0°C, then setpoint =setpoint_T_Ch_high.
If the outdoor temperature = Tout_max=Par. 38, preset
to 18°C, then setpoint T_ch_high_ foot=Par. 18, preset to
50°C.
The setpoint is calculated linearly between the 2 outdoor
temperature values.
Preset to 0.
2
Attenuation_Low
LOW TEMPERATURE circuit attenuation function
(parameter 25)
This paragraph is similar to the previous paragraph for the
low temperature circuit.
There are 2 cases:
- Fixed point operation Par. 22=0
- Operation with climatic control Par. 22=1.
FIXED POINT OPERATION, PAR. 22=0
With low temperature circuit attenuation disabled, Par. 25=0
at the closure of the low temperature circuit thermostat,
heating demand is activated. When opened, the system
turns off.
The Master control unit activates the low temperature
circuit pump if the parameter for the third pump is set to
1 (P34=1).
On the Master control unit, it is possible to set the low
temperature circuit setpoint, Setpoint_T_CH_Low = Par.
3, preset to 40°C and can be set between 10°C and T_
CH_low_limit=Par. 23, which in turn is preset to 50°C. The
setpoint used will be the one set with parameter 3.