Azbil AUR890 Series, Руководство пользователя

Страница: 47 / 62

39
Chapter 5. Trial Operation and Adjustment
„
Pilot turn-down test
WARNING
Make sure that the pilot turn-down test is done properly.
If the flame detector is able to detect a pilot flame that is too small to ignite the main burner, and if
there is a flame failure of the main burner, this device will not be able to recognize the flame failure.
As a result, fuel will continue to be supplied, resulting in an explosion hazard.
Before doing the pilot turn-down test, always make sure that all manual fuel valves are closed.
If the pilot turn-down test must be repeated, stop the combustion equipment completely each time
and discharge all of the unburned gas and oil from the fuel chamber and flue. Failure to discharge
unburned gas may result in an explosion hazard.
After completing the pilot turn-down test, turn off the power switch to turn off the power supply.
Make sure to return all test jumpers and limit or controller settings to their original values.
Resuming normal operation without returning the settings to their original values, etc., may
damage the equipment or cause a gas leak or explosion.
CAUTION
The pilot turn-down test should be carried out by an experienced specialist possessing knowledge
and skills pertaining to combustion equipment and combustion safety.
The purpose of this test is to determine the smallest possible pilot flame that will
reliably ignite the main burner.
Before and after this test, make sure to measure the flame voltage and confirm that
it is 2.0 V or more.
(1) Turn off the power switch and stop all the equipment.
(2) Close the main valve (by removing one side of the wiring to the main valve or by
closing the manual cock) to cut off the gas to the main burner. The pilot valve
remains in its normal state.
(3) Turn on the power switch. If the start input is on, the ignition sequence begins
after the pre-purge, as soon as the pilot valve is opened.
(4) After the pilot burner ignites, turn the pilot valve (manual cock) down until
the burner controller extinguishes the flame. Mark the position of the manual
cock at the time when the flame is extinguished. Then, press the reset switch
to reset the error and restart it. Turn the manual cock back until just before the
previously marked position (so that more gas is output).
(5) Turn off the power switch, return the main valve to the normal state and then
turn on the power switch again. After the pre-purge, pilot burner combustion
begins and then main burner combustion begins.
If the main burner does not ignite, turn off the power switch immediately.
The pilot flame is too small, so it must be increased. In that case, correct the
installation location of the flame detector so that the monitoring angle of the
flame detector is slightly away from the pilot flame monitoring axis.