Initial Checks - Kohler 24RCL Manual

a. This low voltage signal initiates the activator
circuit, which allows 12 VDC input voltage on
leads 55A to flow through the activator board
and to F1--F2 field winding. The alternator
creates voltage in the stator leads and AC
voltage begins to build.
See the alternator service manual, TP-6878,
for detailed information on the alternator
operation.
b. When the RDC2 controller senses that the
engine has reached 750 RPM, the RDC2
controller ends the crank sequence by
dropping power to lead 71, opening the P10
contact, and disconnecting the starter motor.
c. The RDC2 controller will maintain an active
signal on the 3B--5B input to the activator
board, calling for more AC voltage until the
target voltage is achieved.
The ativator board continues to flash the field
using input voltage on lead 55A until
approximately 25 VAC is detected. Once the 25
VAC is detected, the activator board no longer
needs input voltage and removes the voltage
on lead 55A by energizing the P16 flash relay
and opening the P16 contact.
When the RDC2 controller senses the target
voltage on leads V7 and V8, the internal voltage
regulator will transition to a pulse width
modulated signal on 3B--5B to maintain target
voltage.
6. The ECM controls the ignition and throttle to
maintain 1800 RPM.
7. The RDC2 controller monitors alternator voltage
and frequency, annunciates warnings and issues
shutdowns, and monitors the engine sensors
either directly or through CAN communication.
8. Once the engine is running, the ECM controls the
fuel control valve through lead 22 to achieve
stoichiometric combustion.
9. The RDC2 controller monitors the coolant
temperature and switches the radiator fans (RF1
and RF2) from low speed to high speed by
energizing the K2 and K3 relays and changing the
power supply from 6 VDC to 12 VDC.
10. Once the O2 (HEGO) sensor heats up and the
coolant temperature reaches a predetermined
level, the ECM transitions to a closed loop mode,
delivering air and fuel based on O2 sensor input
and engine sensor data. The ECM continues to
control the fuel control valve through lead 22.
62 Section 5 Troubleshooting
11. While monitoring
temperature, the RDC2 controller turns the engine
compartment fan on low speed (6 VDC) by
energizing the K4 relay and on high speed
(12 VDC) by energizing the K5 relay.
12. During shutdown, the controller removes power to
lead 70 and opens the P15 contact.
The ECM no longer receives 12 VDC on inputs
P26-3 and P26--65, the CAN bus stops transmitting
data, and the generator set returns to a
non-running state.

5.3 Initial Checks

When troubleshooting, always check for simple
problems first. Check for the following common
problems before replacing parts:
Loose connections or damaged wiring.
D
Blown fuses. See Section 5.3.2.
D
Dead battery.
D
Inadequate fuel supply.
D
primary or secondary
connections to the fuel solenoid valve, a damaged or
closed fuel shutoff valve, an empty LPG fuel tank, or
other problems with the fuel supply. Check the fuel
supply pressure to the generator set.
Section 6.7, Fuel Systems.
Fault shutdown. Check for a fault message on the
D
controller display. Section 5.6 describes the warning
and shutdown fault messages. If a fault message is
displayed, identify and correct the cause of the fault
condition. Then reset the controller.
Incorrect controller settings. Always check the
D
controller settings before replacing the controller.
See Section 3.3.1 for controller settings. Refer to the
operation manual for instructions to check and
change the controller settings from the controller
keypad, or use a personal computer and Kohlerr
SiteTecht software.
the engine compartment
Check for damaged
fuel regulators, loose
TP-6907 5/16
See