Kohler Power Systems 8RESV Service Manual page 72

Problem Possible Cause
Brush connection
Low output
or
excessive
drop in
voltage,
continued
Low engine speed
causing voltage
roll-off
AC output circuit
No output
breaker open
voltage
Alternator or control
system
Controller
Open wiring,
terminal, or pin in
buildup circuit
Brushes
Rotor slip rings dirty
or corroded
Rotor (open,
grounded, or
shorted windings)
Stator (open,
grounded, or
shorted windings)
Aux. winding circuit
breaker tripped
W/D = Wiring Diagram(s) (Section 7 )
I/M = Generator Set Installation Manual
* RDC2 controller settings can be checked and adjusted using the controller user interface or using a personal computer running SiteTech
software. DC2 controller settings can only be changed using SiteTech.
72 Section 4 Troubleshooting
Test
Check for loose brush
connections.
Check for loose brush mounting.
Check the resistance through the
brushes. Resistance through the
brushes should be low, 0.1--0.2
ohms without meter lead
resistance.
Check system voltage, system
frequency, and engine model
settings.
Check engine speed setting.
Engine problem.
Check for AC voltage on the
generator side of circuit breaker.
If there is AC voltage on the
generator side of the breaker,
then a problem in the load circuits
is causing the line circuit breaker
to trip.
Perform separate excitation
procedure to isolate the problem
to the alternator or the control
system.
Check the controller settings.
Troubleshoot the controller as
described in Section 4.12.
Check wiring.
Inspect brushes.
Check for brushes sticking in
brush holder or broken brush
spring.
Check that brush holder is
securely mounted.
Check slip ring condition.
Check voltage and continuity as
described in Section 5.5.
Check voltage and continuity as
described in Section 5.4.
Check the breaker in the service
access area of the controller.
If breaker trips again, check
stator.
S/S = Generator Set Specification Sheet
Engine S/M = Engine Service Manual
Corrective Action
Tighten loose brush connections.
Tighten mounting screws.
Replace brushes if they show
uneven wear or are worn to
one-half their original length.
Change the controller settings if
not correct. *
Adjust engine speed setting.
Troubleshoot the engine.
Check for and correct short
circuits or overloading on the load
side before resetting the circuit
breaker.
Troubleshoot the alternator or
control system components as
described below and elsewhere in
this table.
Adjust controller settings.
See Section 4.12.
Replace wiring as necessary.
Replace brushes if worn.
Replace brush spring or brush
assembly.
Tighten brush holder screws.
Clean slip rings as described in
Section 5.6. Machine slip rings if
necessary.
Repair or replace rotor if indicated
by the tests.
Repair or replace the stator if
indicated by the test results.
Reset breaker.
If breaker trips again, check
stator.
O/M = Generator Set Operation Manual
Reference
Section 5.7
Section 3.3
Engine S/M
—
Section 5.3
Section 3.3
Section 4.12
Section 7 W/D
Section 5.7
Section 5.7
Section 5.7
Section 5.6
Section 5.5
Section 5.4
Figure 4-2
Section 5.4
TP-6881 7/15