88
the earth or badly worn and must be
replaced. The electronic board is faulty.
In the case of a sudden lack of voltage, the
burner will immediately switch off. When
voltage returns, the boiler will automatically
start up again.
3.8
HEAD AVAILABLE
TO SYSTEM (fig. 14)
Residual head for the heating system is
shown as a function of rate of flow in the
graph in fig. 14.
Portata
(l/ h)
(mbar)
0
PREVALENZA
400
800
1200
778
748
730
701
1600
2000
2400
2800
3200
3600
4000
662
611
555
498
432
353
272
4082
258
PORTATA (l/h)
0
600
500
3000
2500
2000
1500
1000
PREV
A
LENZA RESIDU
A (mbar)
500
400
100
200
300
700
800
3500
4000
Fig. 14
RESIDU
AL
HEAD (mbar)
FLOW RATE (l/h)
Residual head
(mbar)
Flow rate
(l/h)