Interrupted Pilot Diagram - CleaverBrooks CFC Operation, Service & Parts Manual

CB FALCON
Parameter
Purge rate proving
Lightoff rate proving
Pilot type
DBI time
Flame sensor type
Forced recycle interval time
FLAME REQUIRED.
FAILURE TO IGNITE OPTIONS:
• LOCKOUT
• COUNT RECYCLES, THEN LOCKOUT
• COUNT RECYCLES, THEN DELAY MM:SS
• RECYCLE (NO LIMIT)
STANDBY
= CLEAR THE FAILURE-TO-IGNITE
RETRY COUNTER
750-265
Table 31. Burner Control Safety Parameters. (Continued)
None, High Fire Switch, Fan Speed
This parameter determines the input used to confirm the purge rate has been reached. It is
unused and ignored if the Prepurge time is set to zero.
If set to None, the purge rate is commanded during prepurge but purge timing begins
immediately without waiting for any feedback.
If set to High Fire Switch then the HFS input must be on to prove the purge rate. Additionally,
if this is selected and HFS is already on upon exit from Standby then an additional 30 second
prepurge delay (indicating HFS jumpered) is enforced before the measured Prepurge time
begins. If the HFS opens during purge, the burner control will react as specified by the
equipment setup (typically by restarting or holding Prepurge).
If set to Fan Speed then the measured fan speed must be within the specified prepurge rate,
+/- 3% for 3 seconds before the rate is proven and the measured prepurge time begins. If the
fan speed later goes outside of the prepurge rate +/- 10% during purge, the burner control will
react as specified by the equipment setup (typically by restarting or holding Prepurge).
None, Low Fire Switch, Fan Speed
This parameter determines the input used to confirm the rate has been reached for lighting
the burner.
If set to None, the lightoff rate is commanded during ignition but is not checked.
If set to Low Fire Switch then the LFS input must be on to prove the lightoff rate. Additionally,
if this is selected and LFS is already on upon exit from prepurge then an additional 30 second
delay (indicating LFS jumpered) is enforced before the Ignition time begins. If the LFS opens
during ignition, the burner control will react as specified by the equipment setup (typically by
locking out).
If set to Fan Speed then the measured fan speed must be within the specified lightoff rate, +/
- 3% for 3 seconds before the rate is proven and Ignition begins. If the fan speed later goes
outside of the prepurge rate +/- 10% during ignition or MFEP, the burner control will react as
specified by the equipment setup (typically by locking out).
Interrupted, Intermittent, DBI, Direct Burner Ignition Pulsed
An interrupted pilot turns off at the end of the main flame establishing period (MFEP),
whereas an intermittent pilot remains on during the run period and thus there is no MFEP.
The third choice, DBI (direct burner ignition) indicates that there is no pilot and that the main
flame is lit directly using the igniter. The ignition time is fixed at 4 seconds whenever direct
burner ignition is selected.
None, 4 sec, 10 sec, 15 sec
Flame Rod, UV, UV with Spark Interference
Time, None
After scheduled time of continuous run, system is recycled, specifically if UV detector is used
to provide Safe Start.
IGNITER
PFEP
PREPURGE
4 1 , , 0 O
RECYCLE DUE TO
FAILURE TO IGNITE
RECYCLE DUE TO FLAME
FAILURE IN MFEP
Fig. 23. Interrupted pilot.
Comment
IGNITER MAY BE ON THROUGHOUT PFEP, OR ONLY DURING FIRST HALF.
PILOT
MAIN
RUN STABILIZATION
(MAY BE ZERO)
MFEP
R 1 S 5 5, 10, OR 15S
FLAME REQUIRED: LOCKOUT OR RECYCLE
RECYCLE DUE TO FLAME
FAILURE IN RUN
58
R U N P O S P T U R G E