Section 6 – Installation
PRIMEPACT 66G and 66LP Recreational Vehicle Generators
Figure 6.15 – Typical Propane Gas Fuel System | ◆ 6.5.4 PRIMARY REGULATOR |
◆6.5.2 SOME IMPORTANT CONSIDERATIONS
When installing an LP gas system, consider seriously the following items:
•All fittings, lines, hoses and clamps must be tight and free of leaks. Apply a pipe sealant to threads when assembling threaded connections. This reduces the possibility of leakage.
•Test the entire fuel system for leaks using approved test methods.
•Optimum gas pressure at the inlet to the gaseous fuel solenoid valve and secondary regulator is 11 inches water column.
•The installer’s fuel supply connection point is at the gaseous fuel solenoid valve. This is a
•Use a length of approved flexible fuel hose between the gaseous fuel solenoid valve and rigid gas piping. The flexible line should be at least 6 inches longer than necessary.
◆6.5.3 VAPOR WITHDRAWAL
LP gas is stored in pressure tanks as a liquid. The gas systems used with these generators were designed only for vapor withdrawal type systems. Vapor withdrawal systems use the gas vapors that form above the liquid fuel in the tank. Do NOT attempt to use the generator with any liquid withdrawal type system.
Gas pressure delivered to the solenoid valve must be properly regulated by means of a primary gas regulator. Mount the primary regulator at the gas tank outlet or in the supply line from the gas tank. The following rules apply:
•For best results, the primary regulator supplies gaseous fuel to the secondary regulator at 11 inches water column. Do NOT exceed 14 inches water col- umn.
•The installer must be sure the primary regulator is rated at sufficient gas flow to operate the generator plus all other gas appliances in the circuit.
NOTE:
Recommended MINIMUM gas flow rate for all air- cooled PRIMEPACT series generators is 67 cubic feet per hour.
If an existing primary gas regulator does not have a sufficient flow capacity for the generator and other gas appliances in the circuit, (a) install a primary regulator with adequate flow rate, or (b) install a sep- arate regulator only and rated at least 67 cubic feet per hour. The inlet side of any primary regulator that supplies the generator must connect directly to a gas pressure tank. Do NOT tee the generator line into a gas circuit feeding other areas.
◆6.5.5 GASEOUS CARBURETION
LP gas vapors should be supplied to the secondary reg- ulator inlet at about 11 inches water column (positive pressure). The engine pistons draw air in during the intake stroke (Figure 6.16). This air passes through a carburetor venturi, which creates a low pressure that is proportional to the quantity of air being pumped. The low pressure from the carburetor venturi acts on the regulator diaphragm to pull the diaphragm toward the source of low pressure. A lever attached to the diaphragm opens a valve to permit gas glow through the carburetor.
Figure 6.16 – LP Gas Carburetion Diagram
Generac® Power Systems, Inc. 29
