Section 1 - General Information
Guardian
Figure 1.2 - Main Circuit Breaker
Model | Rating | Phase | Actual Current | C/B Rating* | % over rating | Circuit Breaker |
004721/004722 | 15,000 | 1 | 62.5 | 70 | 112% | 70A BQ2 |
004723/004724 | 20,000 | 1 | 83.3 | 90 | 108% | 90A BQ2 |
004725/004726 | 25,000 | 1 | 104.2 | 125 | 120% | 125A BQ2 |
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| * Amp Rating of CB structured under model. |
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Recommended fuels should have a Btu content of at least 1,000 Btus per cubic foot for natural gas and 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.
1.7ENGINE 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
1.7.1 LOW OIL PRESSURE SWITCH
This switch is
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 230°F (110°C), the switch contacts close, which causes the engine to shut down automatically (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 (Figure 1.6 on page 6).
Generac® Power Systems, Inc. 5