Kohler 8.5RES Service Manual page 32

Troubleshooting Chart, continued
Problem Possible Cause
AC output circuit breaker
No output
open
voltage
Alternator or control
system
Aux. winding fuse F1
blown.
SCR module
Controller
Open wiring, terminal, or
pin in buildup circuit or
SCR module circuit
Brushes
Rotor connections
Rotor slip rings dirty or
corroded
Rotor (open, grounded,
or shorted windings)
Stator (open, grounded,
or shorted windings)
Flash relay (K3) on RIB
(ADC 2100)
Flash relay (K3) on
controller board
(ADC-RES)
Exhaust system leaks
Noisy
operation
Engine not running
smoothly
Broken or damaged
vibromount(s)
Loose or vibrating sheet
metal/housing
Exhaust piping or air
inlets/outlets not
securely installed
Excessive
engine/generator
vibration
32 Section 3 Troubleshooting
Corrective Action
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. Check for and correct short circuits or overloading on the
load side before resetting the circuit breaker.
Perform separate excitation procedure to isolate the problem to
the alternator or the control system. Then troubleshoot the
alternator or control system components as follows.
Check fuse F1 and replace if blown. If fuse blows again, check
stator.
Check auxiliary winding fuse F1.
Replace SCR module and test voltage.
Check controller settings. Check wiring and connections.
Before replacing controller, replace SCR module and check
voltage.
Check continuity.
Inspect brushes and replace if worn.
Check for brushes sticking in brush holder or broken brush
spring.
Check for open circuit in rotor connection circuit (leads FN and
FP to SCR and RIB).
Check slip ring condition.
Check voltage and continuity.
Check voltage and continuity.
Check flash LED on RIB.
Check fuse F2 and troubleshoot RIB.
Check fuse F2.
Check flash LED1 on controller board. If LED1 indicates power
to K3 but relay does not operate, replace controller circuit board.
Check and replace as necessary.
See Generator set operates erratically in this table.
Check and replace as necessary.
Retighten screws, replace rivets.
Inspect for loose parts and secure if necessary.
Check, rotor, crankshaft, bearing, etc. (disassembly of engine
and/or alternator may be required).
Reference
—
Section 6.2
Section 6.3
Section 6.13
Section 6.8
Section 4.5 or .
Section 6.8
Sections 6.13
Section 8
Section 6.6
Section 6.6
Section 8
Section 6.4
Section 6.4
Section 6.3
Section 4.8
Section 5.7
Section 2.6
—
Section 7
—
Section 2.6
Section 7
Engine S/M
TP-6196 10/09