Wacker Neuson HI750 Series Operator's Manual page 61

HI750
State
Trial-for-
ignition
Ignition
carryover
Burner-motor-
off-delay
ghi_tx001258gb_FM10.fm
The trial-for-ignition state immediately follows the valve-on-delay state.
During this state:
■
The fuel shut-off valve is opened (energized).
■
Pressurized fuel atomizes at the burner nozzle.
■
The atomized fuel is ignited by the electrodes.
■
The burner fires and the flame is monitored by the cad cell.
■
If flame is detected, the burner control moves to the ignition carryover
state.
If flame is not detected within 15 seconds:
■
The burner control enters the lockout state.
■
Power is disconnected from the fuel shut-off valve, electrodes, and
the burner motor.
The ignition carryover state starts as soon as the flame is established.
During this state:
■
The fuel shut-off valve is open (energized).
■
Pressurized fuel atomizes at the burner nozzle.
■
The atomized fuel is ignited by the electrodes.
■
The electrodes stay powered for up to 10 seconds after flame is
sensed.
When the ignition carryover state has elapsed:
■
The ignition transformer is shut off.
■
The burner control enters the run state.
If the flame is lost during the ignition carryover state:
■
If the lockout time has not expired, the burner control returns to trial-
for-ignition state.
■
If the lockout time has expired, the burner control enters the recycle
mode.
The run state starts and continues once the ignition carryover state has
Run
elapsed. During this state:
■
The fuel shut-off valve is open (energized).
■
Pressurized fuel atomizes at the burner nozzle.
■
The flame is monitored by the cad cell.
When the setpoint is reached (call for heat satisfied), the burner control
enters the burner-motor-off delay state.
If the flame is lost during the run state:
■
The burner control enters the recycle mode.
The burner-motor-off-delay state starts immediately after the setpoint is
reached, i.e., the call for heat has been satisfied. The time of this state
is 30 seconds. During this state:
■
The output contacts of the temperature controller open, interrupting
the circuit between the terminals labeled "T".
■
The fuel shut-off valve closes (de-energizes).
■
The burner motor runs until the burner-motor-off delay expires, then
the burner motor turns off.
■
The burner control returns to the idle mode.
If the cad cell detects flame during the burner-motor-off-delay state:
■
The burner control goes into the standby state.
Action or Function
61
Operation