Kohler COM7.5, Service Manual

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TP-6120 5/02 27 Section 4 Component Testing and Adjustment
4.5.1 Fuel Regulators
The typical gaseous fuel system uses two regulators.
The primary regulator reduces the line pressure to an
allowable inlet pressure for the secondary regulator.
The fuel supplier provides and maintains the primary
regulator. The secondary regulator is factory-installed
on the generator set and is designed for a maximum inlet
pressure of 2.7 kPa (6 oz./in.
2
) or 280 mm (11 in. water
column).
Do not try to adjust the fuel pressure, fuel mixture, or
engine speed using the fuel lock-off. See Figure 4-6 for
the location of the fuel lock-off.
The fuel lock-off
prevents fuel flow when the engine is not operating.
Checking the Fuel Pressure
Use a gauge or manometer to check the fuel pressure at
the secondary regulator inlet. See Figure 4-6. Measure
the fuel pressure with the generator set running at full
load. The fuel pressure should be 178--280 mm (7--11
in. water column) or 1.7--2.7 kPa (4--6 oz./in.
2
). Contact
the fuel supplier if the inlet pressure is not within the
specified range.
Note: Do not attempt to adjust the fuel mixture or engine
speed by adjusting the regulators.
5
1. Dual-fuel block
2. Secondary pressure regulator
3. Fuel inlet
4. Fuel lock-off (Do not adjust.)
5. Fuel metering valves
6. Inlet pressure check location (plug)
tp6120
2
1
3
6
4
Figure 4-6 Secondary Regulator (with fuel block)
4.5.2 Fuel Solenoid Valve
The fuel solenoid valve is a 12 VDC valve energized by
lead 70 when the generator set controller is in the crank
or the run mode. The fuel solenoid valve is supplied by
the enclosure manufacturer.
4.5.3 Fuel Conversion
A dual-fuel block with two fuel metering valves allows
field conversion between natural gas and LP vapor.
Have the fuel conversion procedure performed by
trained and qualified personnel.
Note: The fuel metering valves are factory-sealed to
comply with applicable emission standards and
to provide the best possible hot and cold starting.
The manufacturer ships the generator set with the fuel
system set for natural gas. To convert to LP gas, use the
following procedure to move the fuel line from the
natural gas outlet port to the LP outlet port in the
dual-fuel block (or from the LP outlet to the natural gas
outlet to convert from LP to natural gas). See Figure 4-7
for the LP and natural gas fuel connection and fuel block
locations. Also see the service views in Section 1.4.
1. Fuel block
2. Fuel metering valves
3. LP and natural gas outlet ports
4. Fuel inlet port
1
3
2
photos5--4
4
Figure 4-7 Fuel System (shown mounted on the
shipping bracket)