Section 4 Controller Troubleshooting; Sequence Of Operation; Start; Run - Kohler 5ERKM Service Manual

4.1 Sequence of Operation

This section describes the controller sequence of
operation during the generator start, run, stop, and fault
shutdown modes and describes the relay testing
procedures. Use this section as a starting point for
controller fault identification. Use the LEDs on the
controller circuit board to assist in the troubleshooting
process. An illuminated LED indicates that the
respective relay is receiving power; the LED does not
indicate whether that relay is energized or working
properly. Unfold and use the wiring diagram in
Section 8.5 to follow the sequence of operation in this
section.
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7
6
1. PBIIIE voltage regulator
2. K20 relay
3. K25 relay
4. Controller circuit board
5. Fuses
6. Start/stop switch
7. Hourmeter
Figure 4-1 Controller
TP-6079 3/00

Section 4 Controller Troubleshooting

4.1.1
Press the start/stop switch to the START position to
close the start/stop switch between N and 47 (local or
remote).
The K2 relay energizes and LED2 illuminates. The
normally open K2 contacts close energizing the K3 relay
(LED3 lights), fuel pump (FP), choke heater (CHTR),
antidiesel solenoid (ADS), ignition (IGN), hourmeter
(HR), and the main field (FP and FN).
Flashing of the main field occurs when the K2 contacts
close.
The normally open K3 contacts close energizing the
K20 relay. The normally open K20 contacts close,
2
energizing the starter relay (SR). The SR normally open
contacts close energizing the starter motor (SM).
3
4.1.2
The bridged rectifier (BR1) receives AC voltage
(12--15 volts) through the B1 and B2 windings of the
stator.
4
The K1 relay energizes (LED1 lights).
The normally open K1 contacts close maintaining
voltage to the K2 relay, allowing the function of the fuel
pump (FP), choke heater (CHTR), antidiesel solenoid
(ADS), ignition (IGN), and hourmeter (HR).
The normally closed K1 contacts open, ending the
flashing by preventing battery voltage to the main field
(+) and (--).
The K6 relay energizes. The normally open K6 contacts
close, latching the K6 relay on. The normally closed K6
contacts
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engagement by disabling the the K3 relay.
The K3 relay deenergizes (LED3 off). The K3 contacts
open, deenergizing the K20 relay. The K20 contacts
open, deenergizing the starter relay and starter motor.
At the same time the K1 relay energizes, the time delay
GM11919
for the K5 relay starts. After 5--10 seconds, the K5 relay
energizes (LED 5 lights).
The normally open K5 contacts close permitting the
function of the engine safety shutdown switch.

Start

Run

open, preventing
Section 4 Controller Troubleshooting
inadvertent starter
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