BCU 480 · Edition 06.07
46
Manual mode
5 .8
For convenient setting of the burner or analysing faults.
The parameter display is not available in Manual mode. Man-
ual mode can be accessed only if the unit was not in Fault
state before switching off The following times/functions are not
active in Manual mode: start-up attempts, restart, minimum
combustion time and cycle lock.
If the Reset/Information button is pressed for 2 s during switch-
on, the BCU reverts to Manual mode. Two dots blink on the
display.
In this operating mode, the burner control unit operates inde-
pendently of the status of the inputs (apart from the pre-purge
input and the safety interlocks. These are of higher priority and
will be processed first).
Each time after the button is pressed again, the BCU moves
to the next section of the program sequence and stops there.
Briefly pressing the Reset/Information button (< 1 s) displays
the relevant Manual mode step. When the operating position
is reached (program status
4
(Operation, pilot burner) or
8
(Operation, main burner)), the flame signal is indicated
instead of the program parameter after approx. 3 s. If there
is flame simulation during the start-up, the flame signal is
displayed immediately.
On units with air valve control, the air valve can be opened and
closed repeatedly by pressing the button during operation.
Manual mode can be terminated by switching off the BCU
(On/Off button).
Manual mode limited to 5 minutes
5 .8 .1
Parameter 34
Parameter 34 determines when Manual mode is terminat-
ed.
Parameter 34 = 0: Manual mode is not limited in time. If this
function has been selected, operation of the furnace may
be continued manually in the event of failure of the central
control system.
Parameter 34 = 1: Manual mode ends automatically five min-
utes after the last time the button was pressed. The BCU then
moves abruptly back to start-up position/standby.
Parameters
