Question 28General Subjects - Assistant Engineer
70% to passIf an air compressor is fitted with a hand-off-auto (H-O-A) control station, what statement concerning operation is true?
AIn the hand mode, the compressor will run continuously with unloading.
BIn the hand mode, the compressor will cycle on and off.
CIn the auto mode, the compressor will run continuously with unloading.
DIn the off mode, the compressor will cycle on and off.
AI Explanation
The correct answer is A) In the hand mode, the compressor will run continuously with unloading. In the hand mode of an air compressor with an H-O-A control station, the compressor will run continuously without cycling on and off. The unloading feature allows the compressor to operate without building up pressure, which prevents overloading the system. The other options are incorrect because: B) In the hand mode, the compressor would not cycle on and off; C) In the auto mode, the compressor would cycle on and off based on system demand, not run continuously; and D) In the off mode, the compressor would not be running at all, not cycling on and off.
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