Section 1 - General Information
Guardian
1.6 GENERATOR FUEL SYSTEM | Figure 1.4 - Low Oil Pressure Switch |
The unit has been factory tested and adjusted using a natural gas fuel system. If propane (LP) gas is neces- sary, contact an authorized service dealer.
Fuel pressure for a natural gas set up should be five inches to 14 inches of water column (0.18 to 0.5 psi) at all load ranges.
Fuel pressure for an LP vapor set up should be 11 inches to 14 inches of water column (0.4 to 0.5 psi) at all load ranges.
NOTE:
A seperate gas line and regulator may be needed to assure proper gas pressure to the generator. Improper gas pressure can cause hard starting and affect engine durability.
NOTE:
The Low Oil Pressure, High Coolant Temperature and Low Coolant Level are not monitored for the first 10 seconds of engine run time.
Gaseous fuels such as natural and LP (propane)
!gas are highly explosive. Even the slightest spark can ignite such fuels and cause an explo- sion. No leakage of fuel is permitted. Natural gas, which is lighter than air, tends to collect in high areas. LP gas is heavier than air and tends to settle in low areas.
1.7ENGINE PROTECTIVE DEVICES
The engine has several safety switches which cause the engine to automatically shut down under the fol- lowing conditions: low oil pressure, high coolant tem- perature, engine overspeed, low coolant level or over- crank (Figure 1.3).
Figure 1.3 - Engine Protective Devices
1.7.2 HIGH COOLANT TEMPERATURE SWITCH
This normally open (N.O.) thermostatic switch has sensing tip which is immersed in captive coolant. Should coolant temperature exceed about 230°F (110°C), the switch contacts close. This causes the engine to shut down automatically and turns on the high coolant temperature/low coolant level LED (Figure 1.5).
Figure 1.5- High Coolant Temperature Switch
LOW OIL PRESURE SWITCH
LOW COOLANT LEVEL SWITCH
HIGH
COOLANT 
TEMPERATURE
SWITCH
1.7.1 LOW OIL PRESSURE SWITCH
This switch is
1.7.3 LOW COOLANT LEVEL SWITCH
Should engine coolant level drop below the level of the high coolant temperature switch, it is possible for the engine to overheat without automatic shutdown. To prevent such overheating without automatic shut down, the engine has a low coolant level sensor. If the engine coolant drops too low, the engine automatical- ly shuts down and turns on the high coolant temper- ature/low coolant level LED (Figure 1.6 on page 6).
Generac® Power Systems, Inc. 5