Guardian Technologies 004988-4 Manual De Usuario

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5
1.6 GENERATOR 
FUEL 
SYSTEM
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.
  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.
1.7  ENGINE PROTECTIVE DEVICES
The engine has several safety switches which cause 
the engine to automatically shut down under the 
following conditions: low oil pressure, high coolant 
temperature, engine overspeed, low coolant level or 
overcrank (Figure 1.3).
Figure 1.3 - Engine Protective Devices
LOW OIL
PRESURE
SWITCH
SWITCH
COOLANT
TEMPERATURE
HIGH
LOW COOLANT
LEVEL SWITCH
1.7.1  LOW OIL PRESSURE SWITCH
This switch is normally-closed (N.C.) but is held open 
by engine oil pressure during engine running. Should 
operating oil pressure drop below about 8-10 psi (55-
68 kPa), the switch contacts close, the engine shuts 
down automatically, and the low oil pressure LED is 
turned ON (Figure 1.4).
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Figure 1.4 - Low Oil Pressure Switch
NOTE:
The Low Oil Pressure, High Coolant Temperature 
and Low Coolant Level are not monitored for the 
first 10 seconds of engine run time.
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
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 tempera-
ture/low coolant level LED (Figure 1.6 on page 6).
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Section 1 - General Information
Liquid-cooled 30 kW Generators