standards and guidelines for communication sites - Radio And ...

GENERATOR OUTPUT AND DERATING CONSIDERATIONS CHAPTER 6: POWER SOURCES
• The engine exhaust system pipe and muffler shall be no smaller in diameter or of greater length
than that specified by the manufacturer.
• In areas where the noise levels exceed 85 dBA, warning signs and hearing protection shall be
provided.
6.9.1.2 GENERATORS LOCATED OUTDOORS
If the generator is to be located outdoors, the following requirements shall be met:
• The generator shall be enclosed in a housing sufficiently rugged to protect against weather, animal/
insect ingress, and tampering. This is especially important for the radiator and fuel tank.
• The generator shall be enclosed within a fenced area, with adequate distance between the fence and
the equipment for servicing.
• A muffler shall be used to minimize noise. If the generator is installed near other buildings, a
muffler suitable for use in residential areas shall be used.
• The engine exhaust shall be equipped with a rain cap.
• Locate the generator such that wind will not likely carry dust and moisture into the housing nor
exhaust gases into the building.
• Locate the generator such that required ventilation may be achieved. Most generators exhaust air
outward through the radiator.
• In colder climates other considerations apply. An engine block heater may be required to keep the
engine oil usable.
• Grade relative to fuel source/fuel inlet shall be appropriately considered.
6.9.2 FUEL SUPPLY
Generators may be operated from diesel, liquid propane or gaseous (propane or natural gas) fuels.
Domestically, state and local codes shall be observed because different areas of the country have unique
requirements. Fueling requirements in non-domestic locations shall meet all applicable national and
local codes.
When selecting a generator, determine the standard fuel source for the area and use it whenever possible
to ensure that an adequate fuel supply is available. Where available, utility-provided natural gas
provides the most reliable fuel source and releases the installation from concerns regarding fuel tanks.
In general, the following fueling considerations shall be observed:
• Liquid Propane Gas (LPG) is considered the best all-around backup generator fuel. If possible, an
LPG-configured generator should be considered.
• Diesel and gaseous propane are not well-suited for cold climates. Diesel is no longer allowed for
new generator systems on US Federal lands due to ground contamination concerns. Diesel requires
regular anti-bacterial treatment and water drainage. Diesel must be replaced with fresh fuel
periodically.
• Natural gas requires a reservoir tank in addition to the supply line. If the supply line is severed,
then the generator immediately stops. If natural gas is used, the generator output power will
typically be reduced by 20%, as compared to gasoline. Generator output must be derated
accordingly in these cases.
6-38 68P81089E50-B 9/1/05