Installation manual

Natural Gas Generator Set Installation Manual-GF Series

Doc. 17855, Rel. 03/2014

5-3

1. Air-Fuel Mixture Test Port

2. Solenoid Valve

3. Demand Regulator

4. Carburetor

5. Fuel Mixture Adjuster

6. Natural Gas Supply Pressure Test Port

7. Throttle Body/Governor Actuator

Figure 5-2 Natural Gas Fuel System (Typical)

5.7.2 Fuel System Components

Engine is equipped with one shut-off solenoid valve

and a demand pressure regulator. Gensets for

optional liquid withdrawal of propane are equipped

with a converter that vaporizes the fuel with hot

engine coolant. See Figure 5-2 for a typical fuel

system. A genset equipped for dual fuel, natural gas

and propane, has a gas mixer that serves both fuels.

A fuel pressure switch to detect loss of natural gas

pressure is provided for automatic changeover to

propane while the engine is running. Manual shut-off

valves are provided in each supply line for manual

changeover systems.

5.7.3 Fuel System Operation

During normal operation, the engine fuel/air ratio is

determined by the fuel trim valve operating in con-

junction with the oxygen sensor and the air/fuel

control module. Your authorized Cummins distributor

can monitor fuel system/oxygen sensor operation

using the service tool.

NG-00043