3-9.5. LUBRICATING OIL PRESSURE SWITCH - MAINTENANCE INSTRUCTIONS.
a. The lubricating oil pressure switch is of the "break" type. The lubricating oil pressure switch is
calibrated to break contact when the lubricating oil pressure increases to 10 psi (7.03 gm cm ). The phrase
"10-BREAK" is stamped on the switch cover.
b. As the lubricating oil pressure increases when the engine starts, the diaphragm in the switch body
expands and forces the plunger upwards. Since the bottom of the adjusting screw bears against the plunger
and the adjusting screw is attached to the bracket which controls the upper breaker point arm, 'the arm is also
forced upwards. When the lubricating oil pressure increases to 10 psi (7.03 gm cm), the points separate. If
the lubricating oil pressure decreases to 10 psi (7.03 gm cm) during operation, the breaker point will close and
the alarm will sound.
An alarm will sound in the pilothouse.
This task covers:
INITIAL SETUP :
Special Environmental Conditions
General Safety Instructions
Start engine and operate
at idle speed.