Yanmar 3YM30, Service Manual

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12. Electrical System
189
12.4 Alternator standard, 12V/60A
The alternator serves to keep the battery constantly charged. It is installed on the cylinder block by a
bracket, and is driven from the V-pulley at the end of the crankshaft by a V belt.
The type of alternator used in this engine is ideal for high speed engines with a wide range of engine
speeds. It contains diodes that convert AC to DC, and an IC regulator that keeps the generated voltage
constant even when the engine speed changes.
12.4.1 Specifications
Yanmar code 128271-77200
Model of alternator LR160-741 (HITACHI)
Model of IC regulator SA-A (HITACHI)
Battery voltage 12V
Nominal output 12V/60A
Earth polarity Negative earth
Direction of rotation
(viewed from pulley end)
Clockwise
Weight 4.2 kg
Rated speed
5000 min
-1
Operating speed
1,050-18,000 min
-1
Speed for 13.5V at 20°C
1050 min
-1
or less
Output current for 13.5V
56A or more/ 5000 min
-1
Regulated voltage 14.4
±
0.3V (at 20°C, voltage gradient, -0.01V/°C)