Yanmar 3YM30, Service Manual

Page: 218 / 231

12. Electrical System
197
12.7 Warning devices
12.7.1 Oil pressure alarm
If the engine oil pressure is below 0.01-0.03 MPa (0.1-0.3 kgf/cm
2
, 1.42-4.26 lb/in.
2
), with the main
switch in the ON position, the contacts of the oil pressure are closed by a spring and the lamp is
illuminated through the lamp J oil pressure switch J ground circuit system. If the oil pressure is normal,
the contacts of the switch are opened by the lubricating oil pressure and the lamp remains off.
Rated voltage 12V
Operating pressure
0.04-0.06 MPa
(0.4-0.6 kgf/cm
2
)
Lamp capacity 5 W
Fuse
Oil pressure
(Oil pressure alarm circuit)
Battery
Main switch
Alarm buzzer
Pilot lamp
Oil pressure switch
(Oil pressure switch)
Spring
Oil pressure
Contacts
Lube oil pressure
switch
Cylinder block
Lube oil filter