Westerbeke 7.0 KW BGC -60Hz Technical Manual page 141

NOTE: Three numbered capacitor connections exist: #7, #8, and #9; and two hertz connections, #50
and #60 for the 4.5 BCG and 7.0 BCG. There is only one hertz connection for the 7.0 BCGA - that is
the #60.
Unplug any other connections from the capacitor(s) noting their position on the capacitor.
We want to measure the resistance value of the complete group of exciter windings. Place one of your
ohmmeter leads on the #9 connector and the other on the #50 or the #60 for the 7.0 KW BCGA and
note the value.
Check to make sure there is no continuity to the ground/generator case from either of the two leads.
Also, check that no continuity exists between these exciter leads and any of the main stator winding
leads on the AC terminal block (refer to paragraph B). If continuity is found here, a fault exists between
these two winding groups.
1. Capacitor (Field Testing of the Capacitor[s])
One capacitor is used in the 4.5 and 7.0 KW BCGA generator sets, and two
capacitors in series are used in the 7.0 KW BCG generator set.
With a capacitor meter, test the capacitor following the instructions found with
the meter, and compare the results with the value shown on the capacitor.
When a capacitor meter is not available, follow the simple field test below.
a. Unplug connections from the capacitor. (NOTE: Mark on the connections
so they can be reinstalled correctly.)
Field Testing Capacitor(s)
b. With a jumper, short across the two connections on each capacitor that the two leads in step a were
unplugged from. This will make sure the capacitor is discharged as it should be at shutdown.
c. With your ohmmeter set on the high R scale, place its plus ( +) lead on one capacitor connection
and the negative (-) lead on the other capacitor connection. A resistance should be read and should
rise slowly as the meter attempts to charge the capacitor. This indicates a presumably good
capacitor.
d. Indications of a defective capacitor:
1. Zero resistance - no rise in resistance value (shorted capacity).
2. Infinite resistance - (open capacitor).
3. No continuity should
be
found between the capacitor's connections and the capacitor's
case or base.
137 Westerbeke Generators