Bentone B 70-3, Installation And Maintenance Instruction

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32
Bentone
10.3 Explanation of the different sequence modes
1. Operation
This is the control unit voltage supply.
2. System test
In this status mode, the control unit undergoes
an internal test to verify correct functionality of the
hardware and software.
3.
Preconditions for burner start-up
The control unit verifies that the air pressure switch
is in the depressurised position and a test of the
fuel cut-off valve is carried out.
4. Heating requirement
The operating thermostat closes and voltage is
supplied to connection 5 so that the control unit
can start the burner.
5. Pre-purge begins
The control unit starts the fan. Connections 6 and
7.
6. Damper motor opens
Control unit connection 9 sends a command to the
damper motor to run at Max. mode. The control
unit detects that the damper motor’s end position
switch indicates successful transition to the Max.
load mode by supplying voltage to the connection
8 input. The control unit also performs a test
to ensure that the air sensor detects airflow by
monitoring connection 14.
7. Pre-purge
The combustion chamber is ventilated.
8. Damper motor closes
Following pre-purge, the control unit closes
connection 10. The control unit detects that
the damper motor is in the Low Load mode by
supplying voltage to connection 8 on the control
unit.
9. Ignition on
The control unit supplies voltage to the ignition
transformer by activating connection 16.
10. Fuel on The control unit activates the fuel valve by
supplying voltage to connections 17 and 18 as well
as to direct ignition systems.
11. Flame indication
Ignition transformer turns off. The flame signal is
tested during this stage. If no flame is detected,
the burner enters Lockout mode.
12. Operating mode
Once a flame is stable, the control unit transitions
to Operating mode. There must be a flame signal.
Voltage is supplied to connection 20.
13. Shutdown
Shutdown occurs when the heating requirement
is met and power is cut off to the operating
thermostat connection 5 . The control unit closes
the fuel valves by cutting off power to outputs
18 and 20. The fan post-purges the combustion
chamber.
14. Lockout
The control unit enters lockout mode when an
internal or external fault is detected. The reset
button and the remote-reset connection can be
used to disable Lock mode. However, the control
unit will revert to lockout mode if the fault is not
rectified.
Burner Lockout
When lockout occurs, the LEDs indicate the cause. The control unit status is
saved in the memory, even in the event of a power outage. By pressing the
manual reset button on the control unit or remote reset.