AUTOFLAME Mk8 MM, Техническое руководство, Страница: 41 / 98

2 Flame Safeguard
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MM Application Possibilities
2 FLAME SAFEGUARD
2.1 Burner Control Sequence Diagrams
The time to achieve safety shutdown where a fault is detected is within 4 seconds. The resulting
safety shutdown state is defined by the shut-off valve terminals being de-energised.
The maximum flame failure response time is 1 second.
Diagram Notes
If VPS is not optioned on the fuel selected, the VPS phases are bypassed.
Point idle – this phase is set at power up when no fuel selected on exit from lockout.
Point recycle – this phase is set on exit from firing and post purge if VPS has not operated after
burner run.
Point post purge – this phase is set only if post purge is optioned.
Point standby – this phase is set if VPS has operated after burner run.
Normal lockout is reset when either the mains lockout reset input is set for 2 seconds or the display
screen lockout reset button is pressed for 2 seconds.
Prolonged lockout reset is set if either the mains lockout reset input or display screen lockout reset
input is set for 10 or more seconds. Normal lockout is set on exit from permanent lockout reset after
20 seconds and is reset in the normal way.
Blue waveforms indicate required condition. Values above/below waveform are time in seconds that
the state must be continuously incorrect after which a lockout is set. If the waveform is not bold then
the status is not important.
The following burner control sequence diagrams are shown with example timings:
• 3 second window (±1 second) for UV detection for simulated flame
•
1 second window for UV loss for flame failure
•
3 second window (±1 second) for CPI loss for CPI input wrong state/ no CPI reset
• 3 second window (±1 second) for air switch loss for no air proving
The Mk8 MM and Mini Mk8 MM has the following default timings:
Burner control default timings Seconds
Flame failure response time < 1
Time to achieve safety shutdown < 4
Time to achieve lockout < 1