Guardian 4721, Repair Manual

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GENERAL INFORMATION
SECTION 1.2
PREPACKAGED INSTALLATION BASICS
PART 1
Page 7
11 inches water column for LP gas (6.38 ounces per
square inch), and 5 inches water column for natural
gas (2.89 ounces per square inch). The maximum
recommended pressure is 14 inches water column
(8.09 ounces per square inch). A primary regulator
may be required to ensure that proper fuel supply
pressures are maintained.
DANGER: LP AND NATURAL GAS ARE
BOTH HIGHLY EXPLOSIVE. GASEOUS FUEL
LINES MUST BE PROPERLY PURGED AND
TESTED FOR LEAKS BEFORE THIS EQUIP-
MENT IS PLACED INTO SERVICE AND PERI-
ODICALLY THEREAFTER. PROCEDURES
USED IN GASEOUS FUEL LEAKAGE TESTS
MUST COMPLY STRICTLY WITH APPLICA-
BLE FUEL GAS CODES. DO NOT USE
FLAME OR ANY SOURCE OF HEAT TO TEST
FOR GAS LEAKS. NO GAS LEAKAGE IS
PERMITTED. LP GAS IS HEAVIER THAN AIR
AND TENDS TO SETTLE IN LOW AREAS.
NATURAL GAS IS LIGHTER THAN AIR AND
TENDS TO SETTLE IN HIGH PLACES. EVEN
THE SLIGHTEST SPARK CAN IGNITE THESE
FUELS AND CAUSE AN EXPLOSION.
Use of a flexible length of hose between the genera-
tor fuel line connection and rigid fuel lines is required.
This will help prevent line breakage that might be
caused by vibration or if the generator shifts or set-
tles. The flexible fuel line must be approved for use
with gaseous fuels.
!
VAPOR
LIQUID
LP PRIMARY/ S ECONDARY
S UPPLY REGULATOR
APPROVED FLEX LINE
(CAUTION! — KEEP FLEX FUEL LINE
S TRAIGHT)
11-14 INCHE S WATER
COLUMN OPTIMUM
GENERATOR
DEMAND
REGULATOR
MANUAL S HUTOFF VALVE
GENERATOR BA S E
GA S CARBURETOR
Figure 3. Typical LP Gas Fuel System (Liquid Cooled Units)
NATURAL GA S
PRIMARY
REGULATOR
5-14 INCHE S WATER COLUMN OPTIMUM
GENERATOR
DEMAND
REGULATOR
MANUAL S HUTOFF VALVE
GENERATOR BA S E
GA S CARBURETOR
APPROVED FLEX LINE
(CAUTION! — KEEP FLEX FUEL LINE
S TRAIGHT)
Figure 2. Typical Natural Gas Fuel System (Liquid Cooled Units)