Battery Charger· Testing - Westerbeke 6.5 MCG Service Manual

TESTING THE BATTERY CHARGING CIRCUIT
THE CHARGING SYSTEM
Westerbeke's low profile generators are equipped with a
battery charge controller that is powered from a separate
winding in the generator. The battery charget controller is an
encapsulated, solid-state unit that supplies a DC charging
voltage to the generator's starting
batterywhil~.the
generator·
is operating.
Charging Voltage: 13.0 - 13.4 Volts DC
Charging Amperage: 0 -12Amps DC
BATTCRYCHARGER(f.C.)
Testing the Battery Charging Circuit
NOTE:
The battery charging circuit is totally separate from
the.
AC
o~tput
of the generator. The gene"rator output affects
the circuits output, but not the-reverse.
A
sepal.ite group of stator windings supplies AC voltage to a
bridge rectifier which converts the AC current
to
sppply the
charging unit. The unit senses the needs of the starting
battery and supplies a DC charge when one is needed.
If
you
suspect that the unit is faulty
(if
the battery's charge is low),
check the charging circuit and it's components( see TESTING
THE BATTERY CHARGER). Check
all
connections for
cleanliness and tightness including the ground before
replacing the I.C. charger.
NOTE:
lVhen the generator is first started, the charger will
produce a low charging rate. This. charging rate will rise as
the generator is operated.
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A
wARNING:'
The. Integral battery charge controller is
factory adjusted and sealed. Tampering
with the potentiomBtBr scrBw voids .the
charging systems warranty.
Testing the Battery Charger
To test the battery charger, put a multimeter between the
positive ( +) and negative (-) leads to the battery. It should
indicate 13.0V to 13.4V with the engine running. If only the
battery voltage is indicated, check that the battery charger
tenninal connections are tight. With the unit running. test
between the(+) and(·) on the battery charger (as illustrated)
for 13.0V to 13.4V. If no charge is indicated, replace the
charger.
1.
Bridge Rectifier
Normal AC voltage running to the rectifier (while the
engine is operating at 1800
rpm)
is measured across the
two AC connections on the bridge rectifier. (As
illustrated).
AC voltage running to the bridge rectifier (approximate):
No-load off the
gener~tor
16.0 volts AC
Full-load off the generator 17.5 volts AC
Normal DC voltage running·out
of
the reetifier (in volts
DC) is meas'ured across the two DC connections of the
bridge rect{fier; that is
+
and -.
DC voltage running from the bridge rectifier
·(approximate):
No-load otT the generator
17.0 volts DC
Full-load.off.tlie generator
18.5
volts-D~
2. AC \Vinding: 0.4
ohm
Liftthe two AC wire leads off the bridge rectifier and
measure, the resistance between these two leads with an
ohmmeter.
It
should measure 0.14 ohm. No continuitv
should exist between these two leads and the ground ~r
the main AC stator windings.
Testing the Bridge Rectifier
a. Set the meter on Ohms sca1e. ·
b. Connect the positive ( +) lead from the meter to point #4.
c. Taking the negative (-) lead, momentarily touch points #1, #2,
#3, and #5. There should be no Ohm value registered on the
meter.
d. Remove the positive (+}lead from point #4 and connect the
negative.(-) lead to it. Momentarily touch points'#l, #2 and
#3. the Ohm meter should register an arbitrary ohm value at
each point it touches. ·
e. Leaving the negative (-) lead oil point #4, touch point #5 with
the positive (+)lead. The meter should register no Ohm
value. · ·
, f. Place the positive ( +) lead on point
#1
and the negative (-)
lead on point #3. Th3e meter should register an Ohm value. .
Reverse these connections and the meter should register
an Ohm value.
If the rectifier falls any of the previous test&B through E;
the rectifier' is defective.- replace.
#2
.BRIDGE
RECTIFIER
l"'MTIWESTERBEKE
#4.
· f
Engln'es
&
GeneratQrs
47