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Chapter 5. Trial Operation and Adjustment
Note
•
When turn-down test or communication setting mode is used, pilot burner
combustion continues and there is no limitation on the pilot burner ignition
time. Therefore, the smallest effective pilot flame can be easily determined.
(5) Turn off the power switch, return the main valve to its normal state
(open the manual cock) and then turn on the power switch again. After
prepurge, pilot burner combustion begins, followed by main burner
combustion. If the main burner does not ignite, turn off the power switch
immediately. In this case the pilot flame is too small, so it must be increased.
After increasing the pilot flame, change the position of the flame detector so
that its monitoring angle is slightly away from the pilot flame monitoring axis.
(6) Changing the gas pressure between minimum and maximum, repeat steps (1)
to (5) to check if the main burner ignites without fail.
Handling Precautions
•
If it is necessary to repeat this test, in order to prevent an explosion, stop
all combustion equipment devices each time the test is finished, and
completely discharge unburned gas or fuel that has accumulated in the
chamber, ducts, and flues.
•
Before starting the pilot turn-down test in turn-down test or
communication setting mode, shut off the gas to the main burner by
closing the manual cock or disconnecting the wiring.
z
Safety shutoff check
•
Interlock check
During burner combustion, simulate the operation of each type of interlock and
check if this device is locked out or stops. Then, restart the burners and check for
proper ignition.
•
Pilot ignition failure check
Close the manual gas cock. Turn on the start input of the burners to begin
operation. After prepurge, pilot burner ignition is attempted. Since the manual
cock is closed, however, the pilot burner does not ignite and lockout occurs.
After confirming the above behavior, open the manual cock. Turn on the RESET
switch, restart the burner and check if it ignites normally.
•
Flame failure check
Close the manual gas cock while the burners are operating. After the flame failure
response time elapses, the pilot valve and main valve close and lockout occurs.
After confirming the above behavior, open the manual cock. Turn on the RESET
switch, restart the burner and check if it ignites normally.
•
Power loss (power failure) check
Turn off the power switch during burner operation in order to stop combustion.
After waiting for a while, turn the power back on. Then, turn on the start input to
restart the burners, and check that they ignite properly.
