Ferroli SUN M3 Instrucciones De Uso, Instalación Y Mantenimiento página 38

Minimum gas pressure switch setting
The task of the minimum gas pressure switch is to prevent the burner starting or to stop it if it is in ope-
ration. If the gas pressure is not the intended minimum, it must be set 40% lower than the gas pressure
value in operation with the maximum rate of flow.
Ionization current test
The minimum value of 1μA must be observed with no great swings.
Flame supervision with ionization is accomplished by making use of the conductivity and rectifying effect
of the flame. The flame signal amplifier only responds to the DC current component of the flame signal.
A short-circuit between ionization probe and ground causes the burner to initiate lockout.
Legend
C Electrolytic capacitor 100...470 μF; DC 10...25 V
ION Ionization probe
M Microammeter, Ri max. 5000 Ω
38
fig. 11
Measuring circuit
1
LME...
fig. 12
Cod. 3540G431 - 11/2007 (Rev. 00)
SUN M3 - M6
M
C
ION
EN