A1.4.3 Spark Ignition Duration
The 'pre-ignition' spark time starts 2 seconds before the oil valve
opens (the start of the 5 second 'safety time' period).
The 'post-ignition' spark time ends 3 seconds after the end of the
safety time period, i.e. 8 seconds after the oil valve opens.
The ignition spark is present throughout the 'safety time' period (5
seconds) making a total spark ignition period of 10 seconds.
A1.4.4 Burner Recycle Function
In event of flame failure during burner operation the control box
will allow the burner to recycle and repeat the start-up sequence
for the burner to attempt to re-fire. This can occur up to a total
of three attempts to re-fire the burner. If it fails a fourth time in
operation it will cause a burner lockout and the reset push-button
indicator LED will be RED.
A1.4.5 Burner Lockout
In the event of a burner lockout:
If the reset button is pressed four times in succession, without the
burner being restarted, pressing the reset a fifth time will 'lock' the
reset button. The reset button will flash red and will not respond
to being pressed, i.e. it will no longer operate to attempt to restart
the burner. This is intended to stop the burner reset from being
repeatedly pressed and does not necessarily indicate a fault with
the control box.
If this condition occurs, switch the boiler ON/OFF switch (located
on the boiler control panel) to OFF. Wait for 5 seconds and then
switch it back to ON. The burner reset button should now function
as expected.
Before continuing to press the reset button, the cause of the
original burner lockout, e.g. lack of fuel, no ignition, etc. must be
identified and rectified.
A1.4.6 Post Purge Function
This function allows air flow through the burner for a pre-set time
after the burner flame is switched off (on the loss of demand for
the burner to fire).
The loss of demand from either the heating system controls,
or boiler temperature control, interrupts the switched live to the
burner resulting in the fuel supply being shut off and the flame
stopped. The permanent supply to the burner maintains the fan
operation for a short period to provide the post purging of the
burner and boiler prior to the burner re-firing again.
The post-purge function does not operate:
a) After a burner lockout has occurred
b) If the heat demand is interrupted during the pre-purge period.
However, the post-purge function will operate if the heat demand
is interrupted:
c) During the safety time period (i.e. immediately after burner
ignition)
d) During normal operation of the burner
If the UV cell detects any extraneous light or flame during the pre-
purge period the burner will go to ‘lockout’ after 25 seconds.
If there is a new heat demand during the post-purge period, the
post-purge function is halted (the fan stops) and a new burner
operating cycle starts.
! NOTE !
In the case of continuous ignition sequence recycling
after flame failure, or heat demands close to one another,
the maximum number of cycle repetitions of the ignition
transformer is one attempt every minute.
! NOTE !
After 8½ minutes of continuous burner operation the
control box regains one attempt to re-fire (should it be
required).
If the power supply to the boiler is disconnected and then
reconnected, when the next heat demand is applied to the
burner all three possible attempts to re-fire are restored.
Page 62
Appendix A1: RDB BLU Burner Information
