Service manual
BE
TROUBLESHOOTING
NOTE:
AC
GENERATOR
TROUBLESHOOTING
MUST
BE PERFORMED WITH ENGINE OPERATING
AT
60
HER1Z.
PROBLEM
PROBABLE
CAUSE
No
AC
voltage
output
at
no
load.
Residual
voltage
produced
at
no
load
15
-
20
vOlls
AC.
Low
AC
vO.llage
output
at
no
load
60
-100
VAC.
High
AC
output
voltage
150
VAC
or
higher.
Unstable
voltage
output.
AC
voltage
drop
under
load
60
·100
volts
AC.
r--·----------,
EXCITER
STATOR
1.
2.
3.
1.
2.
1.
2.
1.
1.
1.
Short
or
open
in
the
main
stator
winding.
Shorted
pozi-resistor
on
exciter
rotor.
Four
or
more
shorted
or
open
diodes
on
exciter
rotor.
Blown
6
AMP
buse
fuse
auxiliary
circuit
feed
to
AVR.
Faulty
voltage
regulator
Open
or
shorted
diodes
in
exciter
rotor
1
to
3
diodes.
Open
or
shorted
exciter
rotor
winding
Faulty
voltage
regulator.
STB
pod
on
regulator
needs
adjustment.
Diode(s)
on
exciter
rotor
breaking
down
when
load
is
applied
(inductive)
1-3
diodes.
r-----~----------,
RED
L_
§
....
>-
I I
I I
I
EXCITER
I
ROTOR
FIELD
ili~
I I
:
ROTOR
:
rIDJ
__
..J
I I
L
_____
~-~--------
_________
.J
w
=
....
CD
REGULATOR
ret!
CI
areen
~
"now
.....
~eIIz
... lIIIIp
I
~
~
1---
- -
--1
1
I
STATOR
:
I
AUX
1
______
I
RED
RED
BLUE
YELLOW
Engines & Generators
68
4.
Short
or
open
in
exciter
stator
winding.
5.
Short
or
open
in
rotating
field
winding.
3.
Shorted
or
open
main
stator
auxiliary
winding.
3.
Faulty
voltage
regulator.
2.
Faulty
voltage
regulator.
RED
RED
REO
®
W2
FUSE
U1
GREEN
NOTE:
This
fuse
may
be
located
.
on
the
regulator.
V1
BLACK