Bc Generator Troubleshooting; Exciting The Generator; Main Stator Residual Voltage - Westerbeke 6.5 MCG Service Manual

BC GENERATORS TROUBLESHOOTING
NO AC VOlTAGE OUTPUT
EXCITING THE GENERATOR
To quickly determine a short or an open in the main stator
winding, excite the generator with 12 VDC using one exciter
winding group to accomplish this.. ·
The AC voltage that the generator will produce measured
between the line and neutral during excitation
wi~l
be very
low.
NORMAL AC VOLTAGE DURING
12
VOC EXCITATION:
12-16VOLTSAC [ : . 1-{)
2~
3---Q
~::::
6--0
MAIN STATOR
EXCITING PROCEDURE
Locate one of the exciter winding groups in the generator.
Unplug all connections from both capacitors. Connect 12
VDC across the winding using' the winding end connection, ·
Winding group between #50Hz and
#9.
~ERM~
50Hz 60Hz
7 8 9 9
Jl
7
60Hz 50Hz
• • • • • • J.. • •
12 VOLT OC-t-
REACTION DURING EXCITATION
(Unit running - 12 VDC applied to winding)
NORMAL VOLTAGE DURING EXCITATIIN IS 12 ·16 ·voLTS AC
1. A very low AC output and loading of the drive engine
and a growling boise from the generator end.
This indicates a shorted stator winding to ground or the
stator windings
are
shorted to each other. Isolate the
winding groups and verify a short to ground. No
continuity should be found between the two isolated
stator winding groups.
2. No reaction from the generator or drive engine. No AC
output.
70
This is an indication of an open in one of the main statbr
winding groups. Isolate the winding groups and verify
and open winding.
No Continuity between Isolated Stator Winding Groups
M~
65 432 1
·! ! !
~
TEST EACH OF THE WINDING LEADS
INO/V/OUALLY AS SHOWN
· THERE SHOULD BE NO
GONT/NUITY BETWEEN LEADS
No Continuity between Isolated Stator Windings and Ground
MM\
6~
432 , ,
!·! .
! 6 6 :
~UND
TEST EACH WINDING 'rO CASE GROUND
MAIN STATOR RESIDUAL VOLTAGE
Line to Neutral 4- 6 VAC
(This indicates good stator windings)