Question 5Steam Plants - Assistant Engineer

70% to pass

While trying to light off a burner on a semi-automated boiler, you note that the fuel oil solenoid valve at the burner will not stay open. Which of the following conditions could cause this problem?

AThe fuel oil pressure at that burner is too high.
BThe solenoid coil is energized causing the valve to remain closed.
CThe forced draft air supply has failed.
DThe flame scanner is adjusted for excessive time delay in the ignition trial circuit.
AI Explanation

The correct answer is C) The forced draft air supply has failed. If the forced draft air supply has failed, the lack of air flow to the burner would prevent the fuel oil solenoid valve from staying open. Without the proper air/fuel ratio, the burner would be unable to sustain combustion, causing the solenoid valve to close. The other options are incorrect because: A) High fuel oil pressure would not prevent the solenoid valve from opening. B) The solenoid coil being energized would keep the valve open, not closed. D) Ignition trial circuit timing issues would not affect the solenoid valve operation.

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