Beretta Power Plus Box 1002 P INT, Installation Manual

Page: 31 / 44

31
Mix delivery temperature (°C)
20 30 40 50 60
Valve closing-opening (s)
-4
-3
-2
-1
0
1
3
25 35 45 55
2
Open
Close
default Par. 31 = 10
Fig. 34
Safety functions of the Slave cards
If the delivery temperature > 90°C for 5s, the slave card is
blocked (no. 46).
If the return temperature > 80°C for 5s, the slave card is
blocked (no. 47).
If the flue gas temperature > 80°C for 5s, the slave card
is blocked (no. 48) and the fan operates for 10 minutes at
maximum.
The Slave card is able to protect the primary exchanger
from the hazards of low water circulation both using a flow
switch as well as checking the difference between the de-
livery and return temperatures.
Checking ∆ T uses the parameter ∆ T_max (preset to 35°C)
and limits the burner power as follows:
- if ∆ T_max -5°C > ∆ T > ∆ T_max –10°C = burner mod-
ulated
- if
∆
T_max >
∆
T >
∆
T_max –5°C = burner at minimum
- if ∆ _T > ∆ _T_max = burner off.
Furthermore, the presence of a sensor stops the exchanger
if the pressure inside the combustion unit goes below 0.5
bar.