Lpg Liquid Withdrawal Fuel System Concept; Natural Gas And Lpg Conversion; Fuel System Changeover Kits (Dual Fuel) - Kohler Decision-Maker 3000 Operation

3.6.2 LPG Liquid Withdrawal Fuel
System Concept
With the LPG liquid withdrawal fuel system, pressurized
liquid LPG fuel passes from the tank to a vaporizer. The
vaporizer converts the liquid fuel to gas before sending it
to the fuel mixer. The system also includes a fuel valve
that shuts off the fuel flow when the engine stops.
Contact an authorized service distributor/dealer for
availability.
1 2
1. Primary regulator (supplied by gas supplier or user)
2. Pressure gauge
3. Solenoid valve (UL--listed models require 2 solenoid valves)
4. Secondary regulator
5. Fuel mixer
Figure 3-2 Fuel Regulator and Valve, Typical
3.6.3

Natural Gas and LPG Conversion

Most models operate on either natural gas or LPG fuel
by performing the fuel conversion procedure. A hang
tag on the fuel regulator may provide additional
conversion setup information. Fuel conversion may
decrease generator set output. Refer to the respective
generator set spec sheet for ratings based on fuel
selection. Changing fuel does not alter the emissions
compliance of the generator set engine. Consult your
local generator set distributor/dealer for additional
information.
Note: If a gas-fueled model has the fuel type changed
(LPG to natural gas or natural gas to LPG), order
a new nameplate from an authorized distributor/
dealer with the updated ratings and attach to the
generator set.
To change the fuel type, change the electrical
connections to the engine ECM. The engine ECM has
fuel tables and spark advance curves programmed for
both natural gas and LPG. The information following, in
Figure 3-3, and in Figure 3-4 generally apply to all
models and all fuels. Be sure to review the respective
wiring diagram for your specific model for possible
special applications.
TP-6694 7/11
3 4 5
TP-5750-3
Natural Gas Operation
D
Disconnect lead 65 from lead N5.
D
Disconnect lead 73B from the fuel valve.
D
Connect lead 73A to the fuel valve.
LPG Vapor Operation
D
Disconnect lead 73A from the fuel valve.
D
Connect lead 73B to the fuel valve (LPG vapor).
D
Connect lead 65 to lead N5 (ground).
LPG Liquid Withdrawal Operation
D
Disconnect lead 73A from the fuel valve.
D
Connect lead 73B to the fuel valve (LPG liquid
withdrawal).
D
Connect lead 65 to lead N5 (ground).
Auto Changeover Natural Gas/LPG Vapor
Operation
D
Disconnect lead 65 from N5.
D
Connect lead N5 to LFP2 relay common terminal.
D
Connect lead 73A to the fuel valve (natural gas).
D
Connect lead 73B to the fuel valve (LPG vapor).
Eng. Natural LPG
ECM Gas Vapor
QCON--7
73A (NG fuel
valve)
N5 not used 65
73B not used
65 not used N5
63 LFP1--NC low fuel pressure sensor (if used)
70E2 P6--B (15 amp fuse)
Figure 3-3 Gas Fuel Electrical Connections
3.6.4 Fuel System Changeover Kits
(Dual Fuel)
Automatic Changeover
A changeover fuel system kit provides automatic
changeover from natural gas to LPG vapor.
primary and backup fuels each have a fuel valve. The
primary fuel is natural gas; the backup fuel is LPG
vapor. Before starting, both fuel valves are closed.
When the generator set starts, the primary fuel valve
opens. The primary fuel line has a pressure switch in
series with a relay connected to the start/run circuit.
When the primary fuel pressure drops below 0.6 kPa
2
(1.4 oz./in. ) or 6.4 cm (2.5 in.) water column , a relay
opens the backup fuel valve and closes the primary fuel
valve. When the primary fuel pressure rises above 0.6
2
kPa (1.4 oz./in. ) or 6.4 cm (2.5 in.) water column, the
generator set uses the primary fuel.
authorized service distributor/dealer for kit availability.
Section 3 Scheduled Maintenance
LPG Auto
Liquid Changeover
QCON--7
not used
(NG fuel valve)
65 LFP2--COM
QCON--10 (LPG fuel valve)
N5 not used
Contact an
The
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