Commissioning – Flame Scanner Tests 3-51
FlexFit – Linkageless Control – Revision 1.0
PREFERRED
UTILITIES MFG CORPORATION
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Note that if a position (purge or ignition) needs to be veried, the FlexFit will continue to hold for "P1.2.7 HOLD Alarm Delay"
seconds. At the end of this time, the common alarm horn will sound. If the purge or ignition position has not been veried by the
allowed "P1.2.8 HOLD Lockout Delay" time, the FlexFit will lockout.
Prior to verifying the purge or ignition points, the technician can ne-tune any of the positions as desired by adjusting and
storing that point.
Parameter "P2.5.6 FGR Servo Check Mode" on page 4-70 controls the action of the FGR servo during the servo check proce-
dure. The options are "Closed then Open" or "Open then Closed". The action is usually determined by how the burner manufacturer
wants the position of the FGR damper during the burner purge. To minimize the time it takes for purge to start, this should be set so
the servo check nishes as close as possible to the FGR servo purge position. E.g. if the FGR servo is closed during purge, then the
"P2.5.6 FGR Servo Check Mode" should be set to "Open then Closed".
WARNING
When the commission mode is enabled, all fuel and air outputs to the burner
servos and VSDs are in manual. To ensure safe, efcient combustion, the techni-
cian must use a portable combustion analyzer and visual observations to monitor
stack oxygen, carbon monoxide, NO
X
and smoke emissions, and ame stability.
After the purge position is veried the purge timer will start. At the end of purge, the servos and VSDs will move to the ignition
position and the display will read "Holding: Ignition Position Unveried". Enter the Verify Points sub-menu and verify this position by
pressing ENTER and the display located below S will read "Ignition Position Veried".
After the ignition position is veried, the pilot will energize, (see below for "Flame Scanner Tests") and if a ame is detected, the
sequence will proceed to MTFI. Should pilot and main ame ignition be successful, the servos and VSDs will remain in the ignition
position until that point is stored as the rst point on the combustion curve. Note that this point in the curve does not necessarily
represent the minimum ring rate, nor does it have to be at the same excess air level as at light-off. Prior to storing this rst point on
the combustion curve, the air can be adjusted to a different, more desirable operating excess air level. If the air setting is different
at this rst point versus the ignition position, after the MTFI and at the release to modulate state, the fuel will stay in place and the
air servos and VSDs will adjust to their appropriate curve points. Twenty (20) seconds is allowed for the VSD or air-related servos to
adjust to the curve point. If they fail to do so, a lockout will result.
If either the pilot or main ame did not light, the FlexFit will lockout on ame failure. The purge and ignition points will not have
to be veried again unless the positions in the commission sub-menu are changed. Press the reset push button and the burner
sequence will start again. If the ignition position needs to be adjusted to establish a better pilot or main ame light off, the ignition
position will again need to be veried prior to the start of the PTFI.
Flame Scanner Tests
WARNING
It is the responsibility of the commissioning technician to verify proper operation
of ame detecting equipment and proper ame stability. Every installation is dif-
ferent and the procedures below may need to be modied for your situation.
Pilot Test Hold
The technician can hold the FlexFit in the ignition position to perform a pilot turndown test or to make a ame scanner sighting
adjustment. Navigate to Main Menu > Tuning > Pilot Test Hold to change this option from OFF to ON. When the testing is complete,
change the parameter back to OFF. The sequence will then continue to MTFI. Pilot test hold does not prevent ame failure lockouts.
Pilot Flame Test (Non-DSI Burners)
1. Manually close the main fuel supply valve.
2. Place the FlexFit into Pilot Test Hold. (Navigate to Main Menu > Tuning > Pilot Test Hold to change this option from OFF
to ON).
3. Start the burner by placing the burner switch in ON.
4. If the burner fails to complete purge and move to the PFTI state, verify the proper operation and wiring of all start (recycling)
and running (lockout) switches/interlocks.
5.
Note
If using a self-checking ame scanner, the ame intensity signal
will uctuate every time the amplier does a self-check.
At the start of PTFI, verify that a pilot ame is present and the ame intensity signal is at least 1.25 VDC (≥25%).
Hint
The purge time will not
start until all servos are
at their purge position. To
shorten the wait before
the purge timer starts,
set the purge position of
the fuel servo to an open
position. The fuel servo
will go to the ignition
position at the same time
as the VSD and dampers.
Note
Pilot test hold is ignored
if direct spark ignition
(DSI) is being used.
Note
Ensure the pilot train is
free of air. If the pilot line
and ame scanner appear
to be adjusted properly,
but you can not get a pilot
to light, try cycling the
burner a few times to clear
air from the pilot train.
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