Fuel System Concepts (Pre-Rezg_ And Rezx_/Rzx_ Models); Gas Fuel System Concept; Lp Liquid Withdrawal Fuel System Concept; Lp Gas/Natural Gas Conversion - Kohler Decision-Maker 1 Manual

9.2 Fuel System Concepts
(Pre-REZG_ and REZX_/RZX_
models)
9.2.1

Gas Fuel System Concept

The gas fuel system utilizes a fuel valve with solenoid to
control the fuel flow to the fuel regulator.
generator-mounted regulator reduces fuel pressure as
fuel passes to the gas mixer. See Figure 9-5. The gas
mixer controls the ratio of fuel to air under varying load
and speed conditions. Because the gas mixer receives
fuel in a gaseous state, it does not have to perform fuel
vaporization. When switching from natural gas to LP
gas or LP gas to natural gas, VERIFY THAT ENGINE
SPEED MEETS SPECIFICATIONS.
should compensate for different types of fuel and
maintain rated engine speed.
Carburetor/Gas Mixer Adjustment, for fuel adjustment
when changing fuel type. If engine speed is incorrect,
refer to the governor information to make adjustments.
1 2
1. Primary regulator (supplied by gas supplier or customer)
2. Pressure gauge
3. Solenoid valve
4. Secondary regulator
(shown inverted, position varies by model)
5. Gas mixer
Figure 9-5 Fuel Regulator and Valve, Typical
9.2.2 LP Liquid Withdrawal Fuel System
Concept
With the LP liquid withdrawal fuel system, the tank
directs liquid LP fuel under high pressure to a vaporizer.
The vaporizer converts the liquid fuel to a gaseous state
before sending it to the gas mixer. The system also
includes a fuel valve which shuts off the fuel flow when
the engine stops. See Figure 9-6.
166 Section 9 Gas Fuel Systems
The
The governor
See Section 9.5,
3 4 5
TP-5750-3
2
1
1. Gas mixer
2. Converter (vaporizer)
3. Solenoid valve
4. LP gas filter (supplied by gas supplier or customer)
Figure 9-6 LP Liquid Withdrawal System, Typical
9.3 LP Gas/Natural Gas
Conversion
9.3.1

Straight Gas Fuel System

Most models operate on either LP gas or natural gas fuel
by performing the fuel conversion procedure. Some
models require a different fuel kit when changing gas
fuels.
Fuel conversion may decrease generator set output and
affect exhaust emissions. Refer to the generator set
spec sheet for ratings.
By performing the fuel conversion, some models can
operate on either natural gas or LP gas fuel. The
conversion may require addition/removal of the fuel
regulator spring and retainer.
specific information regarding conversion options. See
Section 9.8, Engine Ignition Timing, for engine timing
information.
Generator
Set Model,
kW Engine
Ford
20
LRG-425
GM 3.0 L,
4.3 L, 5.0 L,
30- -125
5.7 L, 8.1 L,
8.1 L Turbo
Detroit Diesel
135- -180
Series 50
Detroit Diesel
200- -275
Series 60
400- -800 Waukesha
* Some models require new fuel kits for fuel conversion.
Figure 9-7 Fuel Conversion Data
3
TP-5700-6
See Figure 9-7 for
Spring Position
Additional
Natural LP
Adjustments
Gas Gas
and Comments
In Out See Section 9.8
Adjust fuel mixture
and timing. See
In Out
Sections 9.9, 9.10,
9.11, and 9.12
— — Natural gas only
— — Natural gas only
— — Natural gas only
TP-6356 4/12
4