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(5) Close the pilot manual valve slowly. The pilot flame will gradually grow small-
er. Continue to close the manual valve until the flame detector can not detect the
flame.
Record the gas pressure immediately before the flame relay turns OFF and the
combustion lamp is lit up.
(6) Open the manual valve for the pilot slowly to adjust the pressure to a level
immediately before the combustion lamp goes off. Then, press the ignition
switch again to ignite the pilot.
(7) Release the ignition switch.
Open the manual valve for the main burner and check that the main burner
ignites smoothly within one second after the valve is opened.
(8) Try different gas pressures between the minimum and maximum levels, igniting
the main burner five or six times. Make sure that the main burner ignites
smoothly every time.
(9) If the main burner does not ignite properly, the reason is probably that the pilot
flame is too small. Increase the size of the pilot flame, and carry out the follow-
ing adjustment:
• Either slightly take the monitor line of the flame detector away from the axis
of the pilot flame, or stop the iris down to correct the visible flame size. (Set
the flame size so that the main pilot ignites smoothly at the minimum flame
sensitivity.)
(10) After making this adjustment, repeat steps 5 to 8, and make sure that main
burner ignition is reliable.
(11) When this test is completed, return the manual valve for the main burner to its
fully open position. Check that the flame signal is appropriate.
(12) If any limit switch has jumper cables attached, disconnect them to return the
limit switch to its previous state.
Chapter 3. ADJUSTMENTS FOR TRIAL OPERATION
