3.9
FUMES PRESSURE SWITCH
vers. BF-BFT (fig. 16)
The pressure switch is calibrated by the
manufacturer at the following values:
5.3 - 6.3 H
O for vers. "25 BF - 25 BFT"
2
3.6 - 4.6 H
O for vers. "30 BF"
2
4.6 - 5.6 H
O for vers. "20 BF - 35 BFT"
2
which can guarantee boiler functioning also
with aspiration and discharge pipes of the
maximum length allowed.
The value of the signal to the pressure swit-
ch is measured by a differential pressure
gauge connected as indicated in fig. 16.
3. 1 0
HEAD AVAILABLE TO SYSTEM
(fig. 17)
Residual head for the heating system is
shown as a function of rate of flow in the
graph in fig. 17. The speed of the modula-
ting pump is set as default (installation
parameter PAR 13=1).
600
500
400
300
200
100
0
106
200
400
600
velocità max pompa
velocità min. pompa
30-35 BF /GG MT 30-35 PLUS
20 BFT
25 BF/BFT/GG MT 25 PLUS
25 BF/BFT/GG MT 25 PLUS
25-30 OF
25-30 OF
800
1000
PORTATA (l/h)
FLOW RATE (l/h)
Fig. 16
1200
Fig. 17