Generac 004912-0 - Manual (Page 7)

Generac ® Power Systems, Inc. 5
1.5 MAIN CIRCUIT BREAKER
The generator’s main circuit breaker is included with
the unit. The breaker for each unit is described in
Figure 1.2.
1.6 GENERATOR FUEL SYSTEM
The generator has been factory tested and adjusted
using a natural gas fuel system. If propane (LP
requirements) gas is preferred, contact an authorized
service dealer. Refer to Secion 1.12.
Recommended fuels should have a Btu content of at
least 1,000 Btus per cubic foot for natural gas; or at
least 2,520 Btus per cubic foot for LP gas. Ask the
fuel supplier for the Btu content of the fuel being
used.
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 explosion. 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
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 10 psi (68
kPa), the switch contacts close and the engine shuts
down automatically (Figure 1.4).
Figure 1.4 - Low Oil Pressure Switch
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 250°F
(121°C), the switch contacts close, which causes the
engine to shut down automatically (Figure 1.5).
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Section 1 - General Information
Centurion Liquid-cooled 15 kW and 25 kW Generators
Model Rating Phase Actual Current C/B Rating* Circuit Breaker
04912 15,000 1 62.5 70 70A BQ2
04913 25,000 1 104.2 125 125A BQ2
* Amp Rating of CB structured under model.
Figure 1.2 - Main Circuit Breaker