Parameter 51. Type Of Heat Request; Connect At/Bt - Beretta EXCLUSIVE GREEN 25 CSI Installation And User Manual

PARAMETER 51. Type of heat request

IF AN AMBIENT THERMOSTAT IS CONNECTED TO
THE BOILER, SET PARAMETER 51 = 0 (graph 2).
The ambient thermostat makes a heat request when its
contact closes, while it stops it when its contact opens.
Though delivery temperature is automatically calculated
by the boiler, the user may manually override it. By
modifying HEATING on the user interface, the HEATING
SET POINT will no longer be available but just a value
that can be set from +5 to -5°C as required. Modifications
to this value do not directly change delivery temperature
but affect the calculation made to automatically determine
its value by modifying the reference temperature of the
system (0 = 20°C).
For boilers fitted with the S.A.R.A. BOOSTER function,
if the AMBIENT THERMOSTAT remains closed for a long
time, the boiler automatically increases the delivery tem-
perature which is added to the effect of the temperature
control function. When the AMBIENT THERMOSTAT
opens, the boiler automatically returns to the value
determined by the TEMPERATURE CONTROL function.
GRAPH 1
THERMOREGULATION CURVES
100
90
80
70
60
50
40
30
20
20 15 10 5
EXTERNAL TEMPERATURE (°C)
P21 = MAXIMUM HEATING SET POINT
P22 = MINIMUM HEATING SET POINT

CONNECT AT/BT

In case of using CONNECT AT/BT, accessory supplied
on request, the boiler gives the possibility to choose 2
thermoregulation curves:
- OTC 1 CH (parameter 45) for a direct system
- OTC 2 CH (parameter 47) for a mixed system.
Even in case of second circuit (2CH) the curve depends
on the external minimum project temperature (on the
geographical area, therefore) and on the delivey project
temperature (on the type of system, therefore); the
installer must to put attention to calculate it using the
following formula:
rated delivery T - 20
P. 47 = 10 x
20- rated min. external T
Parameters 31 and 32 offrono la possibilità di definire il
massimo e il minimo set-point riscaldamento del secon-
do circuito.
To correct the curve in this configuration, please refer to
the instructions supplied with the accessory.
40 37,5 35 32,5 30 27,5 25 22,5
20
17,5
15
P. 21
12,5
10
40
7,5
5
2,5
P. 22
0 -5 -10 -15 -20
IF A PROGRAMMABLE TIMER IS CONNECTED TO
THE BOILER, SET PARAMETER 51 = 1 (graph 3).
When the contact is closed, the heat request is made by
the delivery probe on the basis of the external tempera-
ture in order to maintain the rated ambient temperature
at the DAY level (20 °C). When the contact opens, it does
not stop the heat request but reduces (parallel shift) the
temperature curve to the NIGHT level (16 °C). Though
delivery temperature is automatically calculated by the
boiler, the user may manually override it.
By modifying HEATING on the user interface, the
HEATING SET POINT will no longer be available but
just a value that can be set from +5 to –5°C as required.
Modifications to this value do not directly change delivery
temperature but affect the calculation made to
automatically determine its value by modifying the
reference temperature of the system (0 = 20 °C for DAY
level; 16 °C for NIGHT level).
GRAPH 2
TEMPERATURE CURVE CORRECTION
90
80
70
60
50
40
30
+ 5 C
0 C
20
- 5 C
10
30 25 20 15
EXTERNAL TEMPERATURE (°C)
GRAPH 3
PARALLEL NIGHT REDUCTION Riduzione notturna PARALLELA
90
80
DAY
70
Curva climatica GIORNO
temperature curve
60
50
40
30
20
10
20 15 10 5
EXTERNAL TEMPERATURE (°C)
27
10 5 0 -5 -10 -15
NIGHT
Curva climatica NOTTE
temperature curve
0 -5 -10 -15
Temperatura Esterna
-20
-20