16
Operation in Run Mode
Start-up Sequence
When a fuel selection is made, and the ‘burner select’ signal is given, the burner will start up. The
control unit will run through the sequence described below.
No
Name
Description
0, 1
INITIALIZE
The unit has just been powered up. If there are no faults,
the unit will immediately proceed to status 3.
Otherwise, it jumps to status 2.
2
SAFETY SHUTDOWN
There is a safety critical fault present which is preventing
the burner from being fired safely.
All drives (motors and inverters) are driven to their close
(P0) positions. The safety shutdown output (PC1-2) and
controlled shutdown output (PC3-4) are both open circuit.
See Faults and fault finding section.
3
BURNER OFF
The safety shutdown output (PC1-2) is closed but the
controlled shutdown output (PC3-4) is open, preventing
the burner from firing.
The unit will proceed to status 4 if:
— Burner select input (PC12) is off (EK5 = 0)
— High/low initiate input (PC11) is off (EK4 = 0)
—þMeasured value below low control limit (EK14 = 1)
If the burner select input (PC12) is on for more than 3
seconds, the unit will go to status 2 with F56.
All drives (motors and inverters) are driven to their close
(P0) positions.
4
WAIT FOR PURGE
The safety shutdown output (PC1-2), the controlled shut
down
output (PC3-4) and the ignition prove output are all closed.
The unit will proceed to status 5 if:
— A valid profile is selected using PC13, 14 and/or 17
— Burner select input (PC12) is on (EK5 = 1)
— High/low initiate input (PC11) is on (EK4 = 0)
— All drives (motors and inverters) are driven to their close
(P0) positions.
5
PROVE CLOSE
The safety shutdown output (PC1-2), the controlled shut
down
(P0) POSITIONS
output (PC3-4) and the ignition prove output are all closed.
All selected motors are driven fully down, and 4mA is output
to the inverters.
The unit will proceed to status 6 if:
— All drives have stopped moving and match their close
(P0) positions to within ±5° (or ±55 for inverters).
— Burner select input (PC12) is on (EK5 = 1)
— High/low initiate input (PC11) is on (EK4 = 1)
— The inverter stop time (option parameter 22.4) has expired
If the burner select (PC12) or high/low initiate (PC11) inputs
are turned off or the profile selection (PC13, 14 and/or 17) is
changed, the unit returns to status 3.
