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T e c h n i c a l N o t e b o o k . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
T e c h n i c a l T r a i n i n g
The gas valve :
The gas valve is designed around a stepper motor controlling a variable valve.
This mechanism has two gas safety solenoid valves powered with low voltage (24 V DC) :
• one on the gas valve inlet (EVS1),
• the other on the stepper motor (EVS2) to ensure that the gas flow is completely cut off even if the motor has not had
the time to close (e.g. after a power cut).
The stepper motor (Vm) controls the flow rate by opening or closing the regulating valve.
EVS2
EVS1
Vm
regulating valve
Burner pressure
restrictor into the gas inlet