22
Stage
no.
Stage name
Description
15.
Moving to low fire
Once the AUTO signal is received the fuel and air motors are moved
from their ignition positions to their low fire positions. These positions
may or may not be the same as the ignition positions. The ‘ignition
prove’ terminal PE7 (low-fire-switch) is switched off.
If the fuel/profile select input is removed (PE9, 10, 11 or 12), the
control will immediately move to status 1.
Once the drives have reached their low fire positions, and an AUTO
signal is received (PA10 - PA11), the control will advance to status
16.
IF Option 23.0 (warming limit) is enabled, drive will remain at low fire
until time set by Option 23.0 expires.
NOTE : terminal PE7 will always be OFF during status 15.
16.
Modulation
(EK33)
Once the fuel and air motors reach their low fire positions, they are
modulated according to the demand placed on the burner.
In this burner status the ‘high-fire-switch’ and ‘low-fire-switch’ outputs
(PE8 & PE7) will come on at high and low fire respectively and may
be used for indication purposes.
If a ‘HIGH’ input is provided by closing PA9 – PA11, this control will
move to status 17.
If the ‘AUTO’ input is removed by opening PA10 – PA11, this control
will modulate down to low fire then jump to status 15. Note : Terminal
PE7 will not be energised in this case. This may be used to provide a
low fire post purge, or a low fire hold function.
If the fuel/profile select input is removed (PE9, 10, 11 or 12), the
control will immediately move to status 1.
If this control wishes to turn the burner off (there is no call for heat, for
example), it will open the ‘controlled shutdown’ relay, removing power
from PE3. It will remain in modulation status however, until one of the
conditions above is met.
17.
Move to post-
purge
The selected motor(s) are moved to their purge positions all others
are moved to their closed positions. When the drives have all
stopped, the control will move to status 18.
18.
Post-purge
The controller confirms all required drives are at their purge positions,
and gives a ‘purge proved’ signal by providing (line voltage) to
terminal PE8 (high-fire-switch).
The control will remain in this status until the burner controller signals
the end of pre-purge by breaking PA9 – PA11 (‘HIGH’ input), or the
fuel/profile select input is removed (PE9, 10, 11 or 12). In either case,
the control will immediately move to status 1.
Summary of Contents for PPC6000 Series
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