Dc Electrical System - Westerbeke 8.0 KW-60Hz SBEG Operator's Manual

DC ELECTRICAL SYSTEM
ALTERNATOR
The charging system consists of a DC belt driven alternator
with a voltage regulator, an engine DC wiring harness, a
mounted DC circuit breaker and abattery Witll connecting
cables. Because of the use of integrated circuits (IC's), the
electronic voltage regulator is very compact and is mounted
internally or on the back of the alternator.
1. Start the engine.
2. After the engine has run for a few minutes, measure the
starting battery voltage at the battery terminals using a
multimeter set on DC volts.
a. If the voltage is increasing toward 14 volts, the alterna·
tor is working; omit Steps 3 through 8 and go directly
to "Checking the Service Battery" on the'next page.
b.Ifthe voltage remains around 12 volts, a problem
exists with either the alternator or the charging circuit;
continue with Steps 3 through 8 .
..---.
#10 REO BATTERY CONNECTOR
STARTER
oo:J
MUlTIMETER
_......-to
COM
#16
51 AMP ALTERNATOR
SEE WIRING DIAGRAM
FOR WIRE CONNECTIONS.
#12
QlArv "m
GROUND ATSTARTER
ALTERNATOR TROUBLESHOOTING
A
WARNING:
A failed alternator can become very
hot. Do.not touch until the alternator has cooled down.
Use this troubleshooting section to determine if a problem
exists with the charging circuit or with the alternator. If it is
determined that the alternator or voltage regulator is faulty,
have a qualified technician check it.
The alternator charging circuit charges the starting battery
and the service battery. An isolator with a diode, a solenoid
or a battery selector switch is usually mounted in the circuit
to isolate the batteries so the starting battery is not discharged
along with the service battery. If the alternator is charging the
starting battery but not the service battery, the problem is in
the service battery's charging circuit and not with the alterna·
tor.
Testing the Alternator
A
CAUTION:
Before starting the engine make certain
that everyone is clear of moving parts! Keep away from
sheaves and belts during test procedures.
A
WARNING:
When testing with
a
multimeter:
DC and AC circuits are often mixed together in marine
applications. Always disconnect
a
shore power cord,
isolate DC and AC converters, and shut down the engine
before perfonning DC testing. No AC tests should be
made without
a
proper knowledge of AC circuits.
8
TESTING THE STARTING
BATTERY/ALTERNATOR
(ENGINE RUNNING)
STARTING BATTERY
-=
GROUND
3. Turn off tile engine. Inspect all wiring and connections.
Ensure that the battery tenninals and the engine ground
connections are tight and clean.
A
CAUTION:
To avoid damage to the battery
charging circuit, never shut off the engine battery
switch when the engine is running!
4. If a battery selector switch is in the charging circuit,
ensure that
it
is on the correct setting.
S. Tum on the ignition switch, but do not start the engine.
6. Check the battelY voltage. If tlle battery is in good condi·
tion, tile reading should be 12 to 13 volts.
TESTING THE
ALTERNATOR VOLTAGE
(IGNITION ON • ENGINE OFF
@:[J
0
COlI
+
MULTI METER
)8
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STARTIN G BATTERY
Engines & Generators
- GROUND
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