Section 6 – Installation
Recreational Vehicle Generators
Figure 6.12 – LP Gas Carburetion Diagram | 6.5.8 EXCESS FLOW VALVE |
The greater the airflow through the carburetor ven- turi, the lower the pressure at the venturi throat. The lower the pressure at the venturi throat, the greater the diaphragm movement, and the greater the move- ment of the regulator valve. The more the regulator valve opens, the greater the gas flow that is propor- tional to airflow through the generator.
The following facts about the secondary regulator must be emphasized:
•The regulator must be sensitive to venturi throat pressure changes throughout the operating range.
•The regulator must be properly adjusted so it will stop the flow of gas when the engine is not running (no air flow through the carburetor).
•The slightest airflow (and vacuum in the venturi throat) should move the regulator valve off its seat and permit gas to flow.
6.5.7 FUEL SUPPLY LINES
•LP gas lines must be accessible, but protected against possible damage.
•Do NOT connect electrical wiring to any LP gas fuel line or run wiring alongside the lines.
•Route gas lines away from hot engine exhausts.
•Retain gas lines with metal clamps that do not have sharp edges.
•Install an approved length of flexible hose between the gaseous fuel solenoid valve and rigid fuel supply lines. The flexible line must be nonmetal- lic, nonorganic and nonconductive. It must be approved for use with LP gas.
DANGER
Gaseous fuel lines between the tank and the secondary regulator are under a positive pres- sure (about 11 inches water column). Gas pres- sure at the outlet side of the secondary regula- tor, however, is a negative pressure and can draw flame inside a line or fitting and cause an explosion.
LP gas tanks should have an excess flow valve, according to NFPA 501C. This valve and the gas lines must be carefully sized so the valve will close when a fuel line is severed or broken. Consult the Natural- LP Gas Association for information and limitations of excess flow valves.
Manual shutoff valves on the supply tank and else- where in the system must be fully open when oper- ating the generator. The excess flow valve functions properly only if all valves are fully open.
6.5.9 LEAKAGE TESTS
Do not place the generator into service until the gas system has been properly tested for leaks. To test the system, a separate source of 12 volts DC to open the gaseous fuel solenoid valve is needed.
The leak test must comply fully with NFPA, Paragraph
318.All connections, hoses, valve regulators, fittings, and other fuel system parts must be tested under gas or air pressure of not less than 90 psi (620 kPa), while using soap and water or an equivalent solution to check for leaks. Other approved methods of testing for leaks may be used, if appropriate. DO NOT USE ANY FLAME TO TEST FOR LEAKS.
6.6EXHAUST SYSTEM
The generator exhaust system must be safely and properly installed. Only approved mufflers and other exhaust system parts must be used. A properly installed exhaust system must be vapor tight, quiet and completely safe.
DANGER
The generator engine gives off DEADLY carbon monoxide gas through its exhaust system. This dangerous gas, if breathed in sufficient con- centrations, can cause unconsciousness or even death. Never operate the generator set with the vehicle inside any garage or other enclosed area. DO NOT OPERATE THE GENERATOR IF THE EXHAUST SYSTEM IS LEAKING OR HAS BEEN DAMAGED. SYMPTOMS OF CARBON MONOXIDE POISONING ARE (a) inability to think coher- ently; (b) vomiting; (c) twitching muscles; (d) throbbing temples; (e) dizziness; (f) headaches;
(g) weakness; and (h) sleepiness. IF FEELING ANY OF THESE SYMPTOMS, MOVE INTO FRESH AIR IMMEDIATELY. IF SYMPTOMS PERSIST, GET MEDICAL HELP. Do not operate the generator until its exhaust system has been inspected and properly repaired.
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